Abstracts of the 31st Bárány Society Meeting, Madrid, Spain, May 9-11, 2022¹

Laboratory characterization of VestAid: a tablet-based technology for objective exercise monitoring in vestibular rehabilitation

Shamus Roeder 1, Pedram Hovaresht1, Lisa Holt1, Pan Gao1, Lemin Xiao1, Devendra Tolani1, Chad Zalkin1, Yonatan Vaknin1, Jody Underwood1, Carlos Esquivel2, Yadira Del Toro2, Susan Whitney3

Intelligent Automation, Inc.1, AFMO SGAR Hearing Center for Excellence, San Antonio, TX, USA,2 University of Pittsburgh, PA, USA3

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We developed and characterized VestAid, an innovative, low-cost home-exercise system that helps patients follow therapists’ instructions and uses the tablet camera to automatically assess compliance in the performance of vestibulo-ocular reflex (VORx1) exercises. The system provides the physical therapist with near real-time objective (head speed, gaze compliance) and subjective (pre- and post- exercise symptoms, perceived difficulty) metrics of compliance through a web-based provider portal.

The system is implemented as a tablet-based app for the patient and a web-based portal for the physical therapist. The physical therapist inputs the parameters of the exercises (suggested dosage, direction and speed of head movement, optotype shape and type, contrast with background). Video instructions on the tablet help patients recall how to perform the VOR exercises and a metronome guides head speed during the exercises. The system collects symptom data before and after each exercise which is then combined with objective performance data to provide feedback to both the patient and the physical therapist.

Using the video stream of head movement, we developed fast and accurate face and facial landmark detection algorithm to compute the head pitch, roll, and yaw angles. A peak detection algorithm is used to determine head speed compliance to VOR x1 set parameters. A Convolutional Neural Network was trained for eye-gaze classification and compliance determination.

We characterized the accuracy of the head angle estimation by comparing its performance on a subset of the BIWI public dataset with Hopenet, a state of art deep-learning method that cannot be implemented on the tablet due to high computational load. Comparable performance to Hopenet was observed with less than10 degrees average geodesic error and less than6 degrees average absolute degrees in yaw plane. We characterized the accuracy of VestAid’s head-turn frequency measurements by performing the head turn exercise with the VestAid system with an Inertial Measurement Unit (IMU) affixed to the back of a head worn helmet. Data from 15 instances of 20 second head-yaw movements with frequencies 80, 120, and 160 bpm yielded a median of average head angle error less than 10 degrees. Publicly available data from 10 persons was utilized to train and evaluate the eye-gaze model, which yielded above 90% accuracy, precision, and recall.

Initial results suggest that the VestAid system can determine the head frequency and eye gaze classification within the required accuracy. Systematic data collection and human studies to further validate the technology are under way.

This work is supported by the US Army Medical Research and Materiel Command under Contract Number listed on W81XWH-18-C-0030. The views, opinions and/or findings contained in this report are those of the author(s) and should not be construed as an official Department of the Army position, policy or decision unless so designated by other documentation.

Prognostic factors that modify outcomes of vestibular rehabilitation in elderly patients with falls

Marcos Rossi-Izquierdo¹, Pilar Gayoso-Diz², Sofía Santos-Perez^3,4, María Del-Rio-Valeiras^3,4, Ana Faraldo-Garcia³, Isabel Vaamonde-Sanchez-Andrade³, Antonio Lirola-Delgado^3,4, Andrés Soto-Varela^3,4

¹Department of Otolaryngology, University Hospital Lucus Augusti, Lugo, Spain; ²Institute of Health Carlos III, Madrid, Spain; ³Department of Otolaryngology, Complexo Hospitalario Universitario de Santiago de Compostela, Spain; ⁴Department of Surgery and Medical-Surgical Specialities, Universidade de Santiago de Compostela, Spain.

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Background: Our previous study has shown that vestibular rehabilitation (VR) is an effective technique to reduce falls in elderly patients. It would be interesting to establish patients’ clinical characteristics in which vestibular rehabilitation is expected to be more effective.

Aims: Evaluate factors that could modify rehabilitation outcomes in elderly patients with previous falls.

Methods: Fifty-seven patients randomized to one of the intervention group (computerized dynamic posturography—CDP—training, optokinetic stimulus or exercise at home) and with previous falls were analyzed. Patients were assessed with objective outcome measures (sensorial organization test and limits of stability—LOS—of CDP, modified timed up and go test—TUG—and number of falls) and with subjective outcome measures (dizziness handicap inventory and Short falls efficacy scale-international—Short FES-I) during a 12-month follow-up period.

Results: In the logistic regression model, a worse score in the maximum excursion (MXM), and a shorter time in the TUG significantly associated with a reduction > 50% of falls. Also, association with a higher score in the Short FES-I was close to a statistical significance. There was no statistical significance association with other covariables.

Discussion: In patients with reduced limits of stability, VR seems to be more effective and they should be encouraged to perform it. But on the other hand, patients with longer time in the TUG show worse outcomes and may benefit more with gait training.

Conclusions: VR in elderly people with previous falls is effective regardless of their age and gender.

Keywords: Vestibular rehabilitation · Outcomes · Prognostic factor · Falls · Elderly

A Tinnitus Suite for two ears and one brain in patients with Meniere’s Disease

Patricia Perez-Carpena^1,2, Marta Martinez-Martinez^2,3; Ramón Antonio Martínez Carranza⁴, Angel Batuecas Caletrio⁴, Jose A. Lopez-Escamez ^1,2,5

¹Department of Otolaryngology, Hospital Universitario Virgen de las Nieves, ibs.Granada, Granada, Spain; ²Otology & Neurotology Group CTS⁴⁹⁵, GENYO - Centre for Genomics and Oncological Research, Granada; ³Department of Otolaryngology, Hospital Universitario San Cecilio, ibs.Granada, Granada, Spain; ⁴Department of Otolaryngology, Hospital Universitario de Salamanca, IBSAL Salamanca Spain; ⁵Department of Surgery, Division of Otolaryngology, Universidad de Granada, Granada, Spain.

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Introduction: Meniere’s disease (MD) is a chronic disorder of the inner ear characterized by vertigo attacks with aural fullness, tinnitus and sensorineural hearing loss. Tinnitus is considered the most annoying symptom, but it is seldom investigated. Although there is no evidence that tinnitus is induced by anxiety, some studies suggest a possible association between these symptoms. Our objective is to perform a psychoacoustic characterization of tinnitus in MD, and to determine if the tinnitus perception is related to anxiety or to the cochlear damage itself, to define an extreme phenotype for tinnitus.

Methods: A cross-sectional multi-center study was designed, including 100 patients diagnosed with defined MD who reported tinnitus, from hospital from Granada and Salamanca. A detailed anamnesis was carried out, including clinical variables (age, gender, age of onset, duration of the disease, uni or bilateral involvement, hearing thresholds, fluctuation and location of the tinnitus) and psychoacoustic variables (type of sound, tinnitus loudness matching, minimum masking level, and residual inhibition). Perceived disability was assessed by a visual analogue scale (VAS) and the Tinnitus Handicap Inventory (THI). Anxiety and depression symptoms were evaluated with the Hospital-Anxiety Depression Scale (HADS).

Results: Tinnitus was permanent in 79 patients. Most of these patients described a tonal tinnitus (n =44), followed by the subgroup of patients describing a noise-like tinnitus (n =35). Meniere’s disease patients with tonal tinnitus presented higher scores in THI compared with the patients with noise-like tinnitus. We found a statistically significant correlation between the scores obtained in VAS and THI (r =0.67; p = 0.001). Both scales showed a moderate correlation with the total HADS score (VAS-HADS, r =0.32, p =0.004; THI-HADS, r =0.56, p =0.001). No statistically significant association was found between these scores and the intensity of tinnitus, the age of patients or the duration of the disease.

Conclusions: Tinnitus is a heterogeneous symptom in patients with MD, which includes tonal and noise like tinnitus. This heterogeneity could be related to the clinical differences described in MD tinnitus. Most patients with MD develop a persistent, constant tinnitus, but few of them report an annoying tinnitus with a significant impact on their quality of life, to be considered a tinnitus extreme phenotype. The type of tinnitus and the hearing involvement in MD have shown a correlation with the disability perceived by patients estimated by the THI.

Visual-inertial heading perception: Effect of heading direction, offset, and visual field size on multisensory integration and perception of common causation

Benjamin T. Crane^1,2,3, Raul Rodriguez³

University of Rochester Departments of Otolaryngology¹, Neuroscience², and Bioengineering³

Visual and inertial cues are the sensory modalities for heading determination. The visual cue is ambiguous as it can represent either self-motion through a fixed environment or environmental motion. When there are offsets between visual and inertial headings, it is only appropriate to integrate them when they are both due to motion through a fixed environment, a situation known as common causation. Difference in heading direction is one factor that makes common causation less likely to be perceived, although surprisingly large differences can be perceived as common causation. We looked at the effects of visual field size, heading offset and direction on common causation and integration. Experiments were done using 102° of the horizontal visual field and 70° of the vertical visual field and these were compared with a visual field of 38° in both directions (11% size). Both inertial and visual stimuli consisted of 2s of synchronized motion. The visual stimulus consisted of a 70% coherence star field. Trial blocks included 12 possible visual and inertial headings which covered the full 360° range in the horizontal plane in 30° increments. Every heading combination was presented in random order with 144 stimuli per block. A dial was used to report the perceived direction of the visual or inertial heading and buttons were pressed to report if the headings were the same or different. Six trial blocks were performed per subject, in 3 blocks inertial heading was reported and in 3 visual heading was reported. In all 6 blocks subjects reported if headings were the same or different. Greatly diminishing the visual field size and removing peripheral vision had a surprisingly small effect on visual direction determination or common causation perception. The lateral component of non-cardinal visual headings (e.g. 30°, 60°) was over-estimated by about 20°. Perception of common causation was also very similar to a full field with common causation which was highest when stimuli were aligned in cardinal directions and very low when stimuli were separated by 90° or more. When offset, visual headings continued to have a large influence on inertial heading perception – 10° with a 30° offset, 8° with 60-90° offsets, and 3° with a 120-150° offset. These were smaller than the offsets seen with the full visual field (13° with a 30° offset, and 13-19° with 60-120° offsets. The inertial stimulus influence on the visual stimulus was minimal (<2°) in both conditions.

ST0066Diagnosis of inner ear disorders using MRI -from animal study to clinical application

Maoli Duan¹, Jun Yang²

¹Department of Otolaryngology Head and Neck Surgery & Audiology and Neurotology and Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden; ²Department of Otolarynggology Head and Neck Surgery, Shanghai Xinhua Hospital, Shanghai Jiaotong University, China

We have performed MRI scanning from in vitro to in vivo animal study and found that the method is useful mean to diagnose inner ear disorders using 4.7 Tesla MRI. The important findings are that Gd cannot enter endolymph but perilymph. We further expanded the findings to patient study using 3.0 Tesla MRI and found that Gd cannot enter endolymph but enter easily in perilymph. Thus, the findings provide critical means to diagnose inner ear diseases.

ST0068Allelic variants in KCNQ2 and KCNQ3 genes in Spanish patients with sporadic Meniere Disease.

Patricia Perez-Carpena^1,2, Alvaro Gallego-Martinez², Sana Amanat²; Pablo Román-Naranjo²; Jose A. Lopez-Escamez^2,3,4

¹Department of Otolaryngology, Hospital Universitario Clínico San Cecilio. ibs.Granada, Granada, Spain; ²Otology & Neurotology Group CTS495, GENYO - Centro de Genómica e Investigación Oncológica, Granada; ³Department of Otolaryngology, Instituto de Investigación Biosanitaria Ibs.GRANADA, Hospital Universitario Virgen de las Nieves, Granada; ⁴Department of Surgery, Division of Otolaryngology, Universidad de Granada, Granada, Spain

Introduction: Meniere’s disease (MD) is a chronic disorder characterized by sensorineural hearing loss, tinnitus, aural fullness and episodic vertigo. The genetic hypothesis of MD relies on the different prevalence observed according to the ethnic background, familial aggregation studies, and the identification of some genes in familial cases. The voltage-dependent potassium channel K7.2/3 has been involved in the dorsal cochlear nucleus in a tinnitus noise-induced mouse model. Our objective is to investigate the role of rare allelic variants in KCNQ2 and KCNQ3 genes in Spanish patients with MD by target exome sequencing.

Methods: DNA samples were obtained from peripheral blood of patients with MD using the DNA Isolation Kit QIAamp DNA Blood Kit (QIAGEN). A target-sequencing panel including coding regions of genes KCNQ2 and KCNQ3 genes was designed and used to sequence 860 patients with MD. After quality filtering, we annotated vcf files using ANNOVAR, adding information for minor allele frequencies (MAF) from several reference population databases and pathogenic prediction tools. Statistical analyses were done with SPSS, Excel and R packages. Gene burden analysis was addressed using 2x2 contingency tables comparing the allelic frequencies with the three reference databases (CSVS from Spain, Non-Finnish European (NFE) from ExAC and gnomAD). Odds ratios with 95% confidence intervals were calculated using Fisher’s exact test, obtaining corrected p-values by Bonferroni’s method.

Results: A total 175 different allelic variants were found in KCNQ2 and KCNQ3 genes. Multiallelic variants and variants with a MAF >0.10 were excluded, obtaining a final set of 71 SNV (11 for KCNQ2 and 60 for KCNQ3). Most of our single variant analyses showed that allelic frequencies were not different when they we compared to reference databases (CSVS, NFE from both ExAC and gnomAD). However, one of the variant observed in KCNQ3 (8:133141822 G>T) showed significant differences when compared to NFE from ExAC and gnomAD, although we could not confirm this difference with Spanish controls. Although gene burden analysis of KCNQ2 and KCNQ3 showed differences for missense variants in KCNQ3 when compared to NFE controls from ExAC and gnomAD, these results were not replicated after comparison with Spanish controls.

Conclusions: Although we observe some promising results in the variant 8:133141822 G>T from KCNQ3, we could not find a burden of missense variants of KCNQ2 and KCNQ3 gene in patients with MD.

Funding. This project was partially funded by the H2020-MSC-ITN-722046 Grant, an European School for Interdisciplinary Tinnitus Research (ESIT).

ST0075The human egomotion network

Ria Maxine Rühl^1,2, Leoni Ophey²,Theresa Raiser, Katharina Seiderer, Virginia Flangin, Matthias Ertl^2,3, Julian Conrad^1,2 and Peter zu Eulenburg^2,4

Department of Neurology¹ and German Center for Vertigo and Balance Disorders² IFB-LMU, Ludwig-Maximilians-University, Munich, Institute of Psychology and Inselspital³, University of Bern, Institute for Neuroradiology⁴, Ludwig-Maximilians-University Munich, Munich, Germany⁴

Theme: Volitional movement in a three-dimensional environment requires multisensory integration, in particular of visual and vestibular signals. In humans, responses to visual egomotion-compatible optic flow stimuli have been demonstrated for multiple cortical areas in the parieto-temporal, cingulate, insular and occipital cortex. Of these regions, areas MST, CSv and VIP have been shown to respond to vestibular stimulation. The egomotion network structure in a comprehensive whole-brain approach however has not been systematically investigated to date.

We applied visual self-motion and galvanic vestibular stimulation using high resolution multi-band neuroimaging to characterize the entire cortical and subcortical egomotion network in humans in a large cohort (n=131). Responses during egomotion perception suggest a network including cortical areas CSv, PcM, human VPS, the cerebellar uvula and an area in the supramarginal gyrus. With respect to its delineated cortical connections and anatomical localization, we propose that this area represents the human homologue of macaque area 7a. The whole-brain functional connectivity analysis point at a central role of the connections between area CSv and the uvula of the cerebellum, possibly representing feedback loops involved in updating visuo-spatial and vestibular information during egomotion. All egomotion hubs showed varying functional connections with visual, vestibular, somatosensory and higher order motor areas, underlining their common function in sensorimotor integration essential for the guidance of locomotion.

Target audience: Clinicians and researchers interested in understanding the structural correlates of the human egomotion system and its functional connections.

ST0076Functional Head Impulse Testing Might Be Useful for Assessing Vestibular Compensation After Unilateral Vestibular Loss

Julia Sjögren, Per-Anders Fransson, Mikael Karlberg, Måns Magnusson, Fredrik Tjernström

Department of Clinical Sciences, Otorhinolaryngology Head and Neck Surgery, Skåne University Hospital, Lund University, Lund, Sweden

Background: Loss of the vestibulo-ocular reflex (VOR) affects visual acuity during head movements. Previous studies have shown that compensatory eye-saccades improve visual acuity and that the timing of the saccade is important. Most of the tests involved in testing VOR are made with passive head movement, that do not necessarily reflect the activities of daily living and thus not being proportionate to symptoms and distresses of the patients.

Objective: To examine differences between active (self-generated) or passive (imposed by the examiner) head rotations while trying to maintain visual focus on a target.

Method: Nine subjects with unilateral total vestibular loss were recruited (4 men and 5 women, mean age 47) and tested with video Head Impulse Test (vHIT) and Head Impulse Testing Device-Functional Test (HITD-FT) during passive and active movements while looking at a target. VOR gain, latencies of covert saccades, frequency of covert saccades and visual acuity were measured and analyzed.

Results: Active head-impulses toward the lesioned side resulted in better visual acuity (p = 0.002) compared to conventional passive head-impulses and generated eye-saccades with significantly shorter latencies (p = 0.004). Active movements to the lesioned side generated dynamic visual acuities that were as good as when testing the intact side.

Conclusion: Actively generated head impulses resulted in normal dynamic visual acuity, even when performed toward the side of total vestibular loss. This might be attributed to the appearance of short-latency covert saccades. The results show a strong relationship between self-generated movements, latencies of covert saccades and outcome in HITD-FT, i.e., a better dynamic visual function with less retinal slip which is the main function of the VOR. The method of active HITD-FT might be valuable in assessing vestibular compensation and monitoring ongoing vestibular rehabilitation.

ST0078Importance of Establishing Protocols in the Sequence of Diagnostic Positional Tests for Posterior and Horizontal Canal BPPV

Anita Bhandari¹, Rajneesh Bhandari², Herman Kingma³, Michael Strupp⁴

(ENT) Vertigo and Ear Clinic, IndiaRajneesh BhandariNeuroEquilibrium Diagnostics, Jaipur, India; ²Department of Ear Nose Throat, Maastricht University, Maastricht, Netherlands; ³Faculty of Physics, Tomsk State National Research University, Tomsk, Russia; ⁴Department of Ear Nose Throat, Aalborg University, Aalborg, Denmark; Professor of Neurology, Department of Neurology and German Center for Vertigo and Balance Disorders, Hospital of the Ludwig Maximilians University Munich, Germany

Introduction: The diagnosis of BPPV is established by the type of nystagmus induced during the different positional tests. The Dix-Hallpike and the diagnostic Sémont manoeuvre are used for the diagnosis of posterior canal BPPV and the Supine Roll test for horizontal canal BPPV. Simulations of the diagnostic tests show how the otolith debris in the canals can be displaced during these manoeuvres, which may have an impact on the test results. In this study, we examined the effect of the sequence of positional tests on diagnosis of canalithiasis affecting posterior and horizontal canals.

Methods: A 3D simulation model was developed based on reconstructed MRI images. Movement of the otolith debris within the canals was tracked with applied fluid dynamic principles (as a function of time). Each canal was linked with the associated extraocular muscles to visualize nystagmus generated by debris movement within the affected canal. Canalithiasis affecting the ampullary and non-ampullary arms of the horizontal canals and posterior canal long arm was studied. Simulations were used to study the movement of the debris during the diagnostic Dix-Hallpike test and Supine Roll test performed from right and left sides.

Results: The simulations show that the Dix-Hallpike and Supine Roll tests could displace the debris within the horizontal canal from its initial position. In contrast, these positional tests did not change the position of the debris in the posterior canal. By changing the sequence of these three tests, different kinds of horizontal nystagmus patterns, such as bilateral direction-changing, bilateral direction-fixed and unilateral nystagmus, were found. We also observed that the Supine roll and Dix-Hallpike diagnostic tests themselves can also result in repositioning of the debris back to the utricle. The simulations show that the diagnostic tests (including the Dix-Hallpike) may already result in repositioning of debris in the horizontal canals back to the utricle. This could explain why it is possible that sometimes no nystagmus is detected during the repositioning manoeuvre in the case of canalithiasis of the horizontal canal after performing the Dix-Hallpike; in contrast, we observed that the Supine Roll test did not affect the position of the debris in the posterior canals.

Conclusions: Depending on the sequence of diagnostic manoeuvres, the change of debris position can result in various nystagmus patterns. Based on the simulations, it is recommended that the Supine Roll test is performed before the Dix-Hallpike test to avoid shifting of the debris in the horizontal canal when testing for posterior canal BPPV.

ST0090Enrichment of Missense Variants in Axonal Guidance Signalling-related genes in Sporadic Meniere’s Disease cases

Alvaro Gallego-Martinez¹, Teresa Requena¹, Pablo Roman-Naranjo¹, Patrick May², Jose A. Lopez-Escamez^1,3,4

¹Otology & Neurotology Group CTS495, Department of Genomic Medicine, GENYO, Centre for Genomics and Oncological Research, Pfizer University of Granada Andalusian Regional Government, PTS, 18016 Granada, Spain; ²Bioinformatics core, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-Sur-Alzette, Luxembourg; ³Department of Otolaryngology, Instituto de Investigación Biosanitaria ibs.Granada, Hospital Universitario Virgen de las Nieves, Universidad de Granada, 18014 Granada, Spain; ⁴Division of Otolaryngology, Department of Surgery, University of Granada, 18011 Granada, Spain

Introduction: Meniere’s disease (MD) is a rare inner ear disorder defined by episodic vertigo, sensorineural hearing loss and tinnitus. MD is suspected to have an important genetic background. Although it has been mostly described in sporadic cases, around 10% of the observed individuals reports familial cases. It is associated with an accumulation of endolymph in the inner ear and the formation of endolymphatic hydrops, but the molecular mechanisms remain still unknown. However, it is suspected that supporting cells of the inner ear may be an important biological target for the disease. Previous studies detected that the main molecular pathways showing higher differentially expressed genes in the supporting cells are related to cochlea-vestibular neuronal innervation, cell-cell adhesion and leucocyte extravasation. In this study, our objective is to analyse a possible burden of rare variants in genes that interact with the main signalling pathways in supporting cells of the inner ear in patients with sporadic MD.

Methods: We designed a targeted-sequencing panel including genes related with the main molecular pathways in supporting cells and sequenced 860 Spanish patients with sporadic MD. We selected variants with minor allele frequencies <0.1 in the gene panel and were compared with three independent population reference datasets (CSVS for spanish population, GnomAD NFE for non-finnish european population and GnomAD ALL for global population). Variants were classified as loss of function, missense and synonymous. Missense variants with a combined annotation dependent depletion score (CADD) of >20 were classified as damaging missense variants. We calculated odds ratio for each gene in the panel for every group of variants in every population frequency dataset. Genes significantly enriched in our cohort for the different comparisons were ranked, pointing to which pathway was more represented by missense variant-enriched genes.

Results: We have observed a significant burden of damaging missense variants in few key genes, including the NTN4 and NOX3 genes, associated with axon guidance signalling pathways in patients with sporadic MD. We have also identified active subnetworks having an enrichment of rare variants in sporadic MD.

Conclusion: The enrichment of missense variants genes such as NTN4 and NOX3 suggests that axonal guidance signalling gene network could be a novel pathway involved in sporadic MD.

Acknowledgments: This study was funded by the Luxembourg National Research Fund Inter/Mobility/17/11772209 grant and EF-0247-2017 from Andalusian Health Government.

ST0091Prevalence and impact of dizziness, unsteadiness and falls in adults positive for COVID-19. An online anonymous survey

Viktoria Azoidou¹, Louisa Murdin², Doris-Eva Bamiou³, Marousa Pavlou¹

¹Centre for Human and Applied Physiological Sciences, King’s College London, London, United Kingdom, ; ²Audiovestibular Medicine Department, Guy’s Hospital, Guy’s and St Thomas NHS Foundation Trust, London, United Kingdom, ; ³Neuto-otology Department, National Hospital for Neurology and Neurosurgery, and Ear Institute, University College London, London, United Kingdom, ; ¹Centre for Human and Applied Physiological Sciences, King’s College London, London, United Kingdom, .

Background: Dizziness and unsteadiness are common clinical manifestations of coronavirus-disease-2019 (COVID-19). Falls were observed in older adults positive for COVID-19. Some COVID-19 survivors, do not fully recover, and experience lingering symptoms for longer than six months. It is not clear how many adults positive for COVID-19 have been affected by dizziness, unsteadiness and/or falls and the impact these symptoms have on their lives.

Methods: A 37-item-close-ended-online-anonymous-survey delivered via Jisc-platform between April-August 2021 aimed to investigate the prevalence and impact of dizziness, unsteadiness and/or falls in adults aged 18-95 years’ old positive for COVID-19 with (Group P) and without (Group N) previous diagnosis of a pathology which provoked these symptoms. Recruitment was via social media, community, and patient organisations representing people with COVID-19 or the investigating symptoms.

Results: In both Group P (n=481, females=390, mean age ±SD= 30.34±13.23 years) and Group N (n=513, females=416, mean age ±SD= 30.99±12.88), dizziness was the most prevalent symptom followed by unsteadiness and falls (Group P: 74.2%, 60.5%, 20.8%; Group N: 74.7%, 61.6%, 18.5%, respectively). The majority of responders experienced these symptoms for >six months (Group P: 60.5%; Group N: 65.7%). Responders experienced dizziness and unsteadiness on a daily basis (Group P: 29.9%, 28.3%; Group N: 22%, 21.1%, respectively), or 1-2 times per week (Group P: 23.3%, 21%; Group N: 28.1%, 25%, respectively) with each episode lasting for a few seconds up to 2 minutes (Group P: 37.2%, 36.2%; Group N: 46.2%, 46%, respectively). Falls were reported by younger adults in both Group P and N (mean age ±SD =33.24 ±13.04 and =35.35±12.17 years, respectively). The most common symptoms triggers were different body movements (Group P: 50.3%; Group N: 46.6%) and moving from a lying down or sitting position to standing up (Group P: 44.1%; Group N: 43.1%). Between- groups there was a statistically higher prevalence in Group P for persons who reported to be severely impacted by dizziness and unsteadiness (37% versus 23%; and 32% versus 18%, respectively) in daily activities. All severely impacted persons in Group P had a previous diagnosis of a pathology causing dizziness and/or unsteadiness with most prevalent peripheral vestibular disorder (88/481), vestibular migraine (43/481), anxiety/stress (41/481), and low blood pressure (41/481).

Conclusions: Persons affected by COVID-19 may experience new onset or exacerbation of previous symptoms of dizziness and unsteadiness and increased incidence of falls for >six months post-COVID with a significant impact on their ability to perform daily activities.

ST0103Sensitivity and Stimulation Characteristics of the Mammalian Vestibular short-latency Evoked Potential

Christopher J. Pastras¹, Ian S. Curthoys², Daniel J. Brown³

¹School of Medical Sciences. The University of Sydney; ²Vestibular Research Laboratory, The University of Sydney; ³School of Pharmacy and Biomedical Science, Curtin University.

The Vestibular short-latency Evoked Potential (VsEP) has been used as an objective measure of vestibular nerve function and represents the synchronous firing of vestibular primary afferents to the onset of motion. It was first termed the short latency vestibular evoked potential by Elidan et al. in 1982 due to its similarity to the auditory brainstem evoked potential. Since then, the VsEP has been measured in various vertebrate models and preparations; the most common being a non-invasive, scalp recording to linear-jerk pulses. This approach is attractive for several reasons, such as the ability to measure vestibular nerve function in chronic recovery animal models without disturbance of the labyrinth. However, with the cochlea intact, this approach is prone to auditory contamination, making interpretation difficult. Given the increased popularity of the VsEP in recent years, it’s important to validate key features of the response for future interpretation and use. This work aimed to characterise the near-field VsEP recorded close to the vestibular afferents from facial nerve canal in anaesthetized guinea pigs. Linear-jerk pulses of varying widths (~0.1-3ms) were used to evoke the VsEP and were compared to responses with the cochlea intact, before and after controlled experimental manipulations, such as acoustic-masking, changes in stimulation rate, and cochlear ablation. Responses from the facial nerve canal were also compared to the vertex. Responses evoked by a 2ms jerk pulse were not suppressed by acoustic forward-masking but were significantly masked using continuous broadband noise. Changing the stimulation rate was used to characterise differences in cochlear and vestibular neuronal forward masking. With the cochlea intact, 50% of the response was forward-masked with a stimulation rate of 60Hz, whereas the response after cochlear ablation did not forward-mask. Overall, surgical ablation of the cochlea revealed significant cochlear contribution of the response across all linear-jerk pulse widths. An iso-acceleration, iso-jerk, and iso-VsEP paradigm was used to probe the kinematic vector sensitivity of the VsEP. Surprisingly, results indicate that the VsEP scales with linear acceleration of the earbar, rather than kinematic jerk. Interestingly, responses with the cochlea intact from both the facial nerve canal and vertex, scaled with kinematic jerk, rather than acceleration. This work reveals new findings that call into question the original interpretation of the sensitivity and stimulation characteristics of the mammalian VsEP.

The target audience is basic vestibular researchers; however, we believe this work will be of interest to a wide readership such as clinicians.

ST0104Similarities and Differences between Vestibular and Cochlear Systems – In Vivo Evoked Potentials.

Christopher J. Pastras¹, Daniel Brown², Ian Curthoys³

¹School of Medical Sciences. The University of Sydney; ²School of Pharmacy and Biomedical Science, Curtin University; ³Vestibular Research Laboratory, The University of Sydney

Auditory evoked potentials have been critical to our understanding of mammalian cochlear function and hearing loss. These measures have allowed a differential assessment of auditory hair cell and neural dysfunction in experimental animal models of disease, such as endolymphatic hydrops and ototoxicity. However, their vestibular counterparts have been more challenging to record due to difficulties in stimulating (and recording) from the labyrinth in isolation of the cochlea. Recently, however, gross utricular nerve and hair cell responses have been recorded from the facial nerve canal and utricular macula of anaesthetized guinea pigs, following cochlear ablation. Vestibular nerve measurements include the Vestibular short-latency Evoked Potential (VsEP) and the Vestibular Nerve Neurophonic, while vestibular hair cell responses include the Utricular Microphonic and utricular Summating Potential. These vestibular responses are analogous to the widely recorded cochlear evoked responses; the Compound Action Potential, Auditory Nerve Neurophonic, Cochlear Microphonic, and Summating Potential. The ability to record similar response measures across inner ear sensory systems highlights commonalities in hair cell and afferent receptor mechanisms and sensory coding. However, clear and important differences exist, such as distinctions in response threshold, sensitivity, dynamic range, frequency selectivity, and characteristics of peripheral response generators, such as, stereocilia polarisation, etc. Comparisons of these response measures can enhance our basic understanding of inner ear physiology, as well as provide a more holistic understanding of cochleovestibular disorders and related therapies.

The target audience is primarily basic inner ear researchers and physiologists; however, we believe this work will be of interest to a wide readership, such as clinicians.

ST0108Galvanic Vestibular Stimulation Improves Spatial Cognition After Unilateral Labyrinthectomy in Mice

Thanh Tin Nguyen^1,2,3†, Gi-Sung Nam^2,4†, Jin-Ju Kang^2,5, Gyu Cheol Han⁶*, Ji-Soo Kim⁷, Marianne Dieterich^8,9,10 and Sun-Young Oh^1,2,5*

¹Jeonbuk National University College of Medicine, Jeonju, South Korea; ²Department of Neurology, Jeonbuk National University Hospital & School of Medicine, Jeonju, South Korea; ³Department of Pharmacology, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam; ⁴Department of Otorhinolaryngology-Head and Neck Surgery, Chosun University College of Medicine, Kwangju, South Korea; ⁵Research Institute of Clinical Medicine of Jeonbuk National University-Jeonbuk National University Hospital, Jeonju, South Korea; ⁶Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Gachon University of Medicine and Science, Incheon, South Korea; ⁷Department of Neurology, Seoul National University Hospital & School of Medicine, Seoul, South Korea; ⁸Department of Neurology, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany. ⁹-German Center for Vertigo and Balance Disorders-IFB, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany. ¹⁰-Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.

Objectives: To investigate the deficits of spatial memory and navigation from unilateral vestibular deafferentation (UVD) and to determine the efficacy of galvanic vestibular stimulation (GVS) for recovery from these deficits using a mouse model of unilateral labyrinthectomy (UL).

Methods: Thirty-six male C57BL/6 mice were allocated into three groups that comprise a control group and two experimental groups, UVD with (GVS group) and without GVS intervention (non-GVS group). In the experimental groups, we assessed the locomotor and cognitive behavioral function before (baseline) and 3, 7, and 14 days after surgical UL, using the open field (OF), Y maze, and Morris water maze (MWM) tests. In the GVS group, the stimulations were applied for 30 min daily from postoperative day (POD) 0–4 via the electrodes inserted subcutaneously close to both bony labyrinths.

Results: Locomotion and spatial cognition were significantly impaired in the mice with UVD non-GVS group compared to the control group. GVS significantly accelerated recovery of locomotion compared to the control and non-GVS groups on PODs 3 (p < 0.001) and 7 (p < 0.05, Kruskal–Wallis and Mann–Whitney U tests) in the OF and Y maze tests. The mice in the GVS group were better in spatial working memory assessed with spontaneous alternation performance and spatial reference memory assessed with place recognition during the Y maze test than those in the non-GVS group on POD 3 (p < 0.001). In addition, the recovery of long-term spatial navigation deficits during the MWM, as indicated by the escape latency and the probe trial, was significantly better in the GVS group than in the non-GVS group 2 weeks after UVD (p < 0.01).

Conclusions: UVD impairs spatial memory, navigation, and motor coordination. GVS accelerated recoveries in short- and long-term spatial memory and navigation, as well as locomotor function in mice with UVD, and may be applied to the patients with acute unilateral vestibular failure.

ST0109Effects of Galvanic Vestibular Stimulation on Vestibular Compensation in Unilaterally Labyrinthectomized Mice

Gi-Sung Nam^1,2†, Thanh Tin Nguyen^1,3,4†, Jin-Ju Kang^1,3,5, Gyu Cheol Han⁶* and Sun-Young Oh^1,3,5*

¹Jeonbuk National University College of Medicine, Jeonju, South Korea; ²Department of Otorhinolaryngology-Head and Neck Surgery, Chosun University College of Medicine, Gwangju, South Korea; ³Department of Neurology, Jeonbuk National University Hospital & School of Medicine, Jeonju, South Korea; ⁴Department of Pharmacology, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam; ⁵Research Institute of Clinical Medicine of Jeonbuk National University-Jeonbuk National University Hospital, Jeonju, South Korea; ⁶Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Gachon University of Medicine and Science, Incheon, South Korea.

Objectives: To investigate the ameliorating effects of sinusoidal galvanic vestibular stimulation (GVS) on vestibular compensation from unilateral vestibular deafferentation (UVD) using a mouse model of unilateral labyrinthectomy (UL).

Methods: Sixteen male C57BL/6 mice were allocated into two groups that comprise UL groups with GVS (GVS group, n = 9) and without GVS intervention (non-GVS group, n = 7). In the experimental groups, we assessed vestibulo-ocular reflex (VOR) recovery before (baseline) and at 3, 7, and 14 days after surgical unilateral labyrinthectomy. In the GVS group, stimulation was applied for 30 min daily from postoperative days (PODs) 0–4 via electrodes inserted subcutaneously next to both bony labyrinths.

Results: Locomotion and VOR were significantly impaired in the non-GVS group compared to baseline. The mean VOR gain of the non-GVS group was attenuated to 0.23 at POD 3 and recovered continuously to the value of 0.54 at POD 14, but did not reach the baseline values at any frequency. GVS intervention significantly accelerated recovery of locomotion, as assessed by the amount of circling and total path length in the open field tasks compared to the non-GVS groups on PODs 3 (p < 0.001 in both amount of circling and total path length) and 7 (p < 0.01 in amount of circling and p < 0.001 in total path length, Mann–Whitney U-test). GVS also significantly improved VOR gain compared to the non-GVS groups at PODs 3 (p < 0.001), 7 (p < 0.001), and 14 (p < 0.001, independent t-tests) during sinusoidal rotations. In addition, the recovery of the phase responses and asymmetry of the VOR was significantly better in the GVS group than in the non-GVS group until 2 weeks after UVD (phase, p = 0.001; symmetry, p < 0.001 at POD 14).

Conclusion: Recoveries for UVD-induced locomotion and VOR deficits were accelerated by an early intervention with GVS, which implies that GVS has the potential to improve vestibular compensation in patients with acute unilateral vestibular failure.

ST0110Vibration-Induced Downbeat Nystagmus: A New Cerebellar Sign Observed in Paraneoplastic Cerebellar Degeneration Associated with Anti-Ri Antibody

Jong-Hee Lee¹, Hyo-Jung Kim², Ji-Soo Kim^1,3

¹Dizziness Center, Seoul National University Bundang Hospital, Seongnam, Korea; ²Research Administration Team, Seoul National University Bundang Hospital, Seongnam, Korea; ³Department of Neurology, Clinical Neuroscience Center, Seoul National University Bundang Hospital, Seongnam, Korea

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Vibratory stimuli on the sternocleidomastoid muscle or skull may enhance the vestibular asymmetry and evoke nystagmus. This vibration-induced nystagmus (VIN) mostly beat toward the healthy or less affected ear in unilateral or asymmetric peripheral vestibulopathy. We report downbeat VIN, a hitherto undescribed sign, in a patient with paraneoplastic cerebellar degeneration (PCD) due to cervix cancer with a peritoneal metastasis and anti-Ri antibody. This 47 year-old women had suffered from dizziness and imbalance for several months after the diagnosis, and examination showed spontaneous upbeat nystagmus with and without visual fixation that decreased during the lateral gazes and changed into downbeat nystagmus during convergence. The spontaneous upbeat nystagmus also changed into downbeat after horizontal head-shaking for about 15 seconds and during vibratory stimuli on either mastoid and the forehead. Additional findings included positional downbeat nystagmus, impaired smooth pursuit, hypermetric horizontal saccades, and truncal ataxia. The dizziness and ataxia did not respond to steroid pulse and intravenous IgG therapy. Along with head-shaking nystagmus, the downbeat VIN observed in our patient indicates a cross coupled responses of the vestibular system during or after stimulation of the semicircular canals or otolithic organs due to cerebellar dysfunction. Vibration-induced downbeat nystagmus should be added to the list of central vestibular signs, probably due to cerebellar dysfunction.

ST0111The Differential Effects of Acute Right- vs. Left-Sided Vestibular Deafferentation on Spatial Cognition in Unilateral Labyrinthectomized Mice

Thanh Tin Nguyen^1,2, Gi-Sung Nam^3,4, Jin-Ju Kang^1,4, Gyu Cheol Han⁵, Ji-Soo Kim⁶, Marianne Dieterich^7,8,9 and Sun-Young Oh^1,4*

¹Department of Neurology, Jeonbuk National University Hospital & School of Medicine, Jeonju, South Korea; ²Department of Pharmacology, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam; ³Department of Otorhinolaryngology-Head and Neck Surgery, Chosun University College of Medicine, Gwangju, South Korea; ⁴Research Institute of Clinical Medicine of Jeonbuk National University-Jeonbuk National University Hospital, Jeonju, South Korea; ⁵Department of Otolaryngology-Head and Neck Surgery, Gachon University of Medicine and Science, Graduate School of Medicine, Incheon, South Korea; ⁶Department of Neurology, Seoul National University Bundang Hospital & School of Medicine, Seoul, South Korea; ⁷Department of Neurology, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany; ⁸German Center for Vertigo and Balance Disorders-IFB, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany; ⁹Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.

Objectives: This study aimed to investigate the disparity in locomotor and spatial memory deficits caused by left- or right-sided unilateral vestibular deafferentation (UVD) using a mouse model of unilateral labyrinthectomy (UL) and to examine the effects of galvanic vestibular stimulation (GVS) on the deficits over 14 days.

Methods: Five experimental groups were established: the left-sided and right-sided UL (Lt.-UL and Rt.-UL) groups, left-sided and right-sided UL with bipolar GVS with the cathode on the lesion side (Lt.-GVS and Rt.-GVS) groups, and a control group with sham surgery. We assessed the locomotor and cognitive-behavioral functions using the open field (OF), Y maze, and Morris water maze (MWM) tests before (baseline) and 3, 7, and 14 days after surgical UL in each group.

Results: On postoperative day (POD) 3, locomotion and spatial working memory were more impaired in the Lt.-UL group compared with the Rt.-UL group (p < 0.01, Tamhane test). On POD 7, there was a substantial difference between the groups; the locomotion and spatial navigation of the Lt.-UL group recovered significantly more slowly compared with those of the Rt.-UL group. Although the differences in the short-term spatial cognition and motor coordination were resolved by POD 14, the long-term spatial navigation deficits assessed by the MWM were significantly worse in the Lt.-UL group compared with the Rt.-UL group. GVS intervention accelerated the vestibular compensation in both the Lt.-GVS and Rt.-GVS groups in terms of improvement of locomotion and spatial cognition.

Conclusion: The current data imply that right- and left-sided UVD impair spatial cognition and locomotion differently and result in different compensatory patterns. Sequential bipolar GVS when the cathode (stimulating) was assigned to the lesion side accelerated recovery for UVD-induced spatial cognition, which may have implications for managing the patients with spatial cognitive impairment, especially that induced by unilateral peripheral vestibular damage on the dominant side.

ST0113Selectively Targeting Efferent Synaptic Mechanisms in the Mouse Inner Ear

Choongheon Lee¹, Anjali Sinha², Kenneth Henry^1,2, Anqi W. Walbaum³, Peter A. Crooks³, Joseph C. Holt^1,2,4

¹Department of Otolaryngology, University of Rochester, Rochester, NY, United States; ²Department of Neuroscience,University of Rochester, Rochester, NY, United States; ³Department of Pharmaceutical Sciences, College of Pharmacy,University of Arkansas for Medical Sciences, Little Rock, AR, United States; ⁴Department of Pharmacology & Physiology,University of Rochester, Rochester, NY, United States

Electrical stimulation of inner ear efferents gives rise to a number of diverse effects on vestibular and auditory physiology. The bulk of these effects are the product of acetylcholine (ACh), the predominant efferent neurotransmitter, and subsequent activation of several ACh receptors (AChRs) and downstream modulation of potassium channels on afferents and hair cells in the cochlea and vestibular endorgans. On the vestibular side, pharmacological evidence has suggested that efferent-mediated fast of vestibular afferents is mediated by α4β2*-containing nicotinic AChRs (nAChRs) while efferent-mediated slow excitation of vestibular afferents is mediated by the activation of muscarinic AChRs (mAChRs) and subsequent closure of KCNQ potassium channels. In contrast, activation of α9α10-nAChRs and SK2 potassium channels in type II hair cells gives rise to efferent-mediated inhibition of vestibular afferents. On the auditory side, efferent-mediated suppression of the compund action potential and distortion product otoacoustic emissions (DPOAEs) is also mediated by α9α10nAChRs and SK2 channels in outer hair cells. Previous pharmacological characterization of the above synaptic mechanisms have primarily relied on the use of systemically-administered cholinergic drugs that, in addition to entering the inner ear, also readily access the CNS and other peripheral tissues where they could interact with similar synaptic mechanisms. Some of these off-target effects could potentially complicate interpretation of our pharmacological observations and certainly may limit the use of these drugs in behavioral paradigms designed to probe efferent mechanisms in the inner ear. To avoid or minimize these off-target effects, we thought that the use of peripherally-acting cholinergic drugs in combination with different administration strategies might be of some utility. However, details about whether such drugs can enter the ear were lacking. Using a variety of administration routes, we performed both vestibular afferent and DPOAE recordings during efferent stimulation in mice to characterize whether charged mAChR or α9α10nAChR antagonists, that exhibit little CNS entry, still retain their ability to target these synaptic mechanisms in the inner ear. We can report that systemic, middle ear, or direct perilymphatic administration of the charged mAChR antagonists glycopyrrolate and methscopolamine will block efferent-mediated slow excitation of mouse vestibular afferents. Furthermore, the same data also reveal these mAChR antagonists can move from one ear to the other. The charged α9nAChR antagonists, however, were ineffective when administered systemically and only blocked efferent-mediated suppression of DPOAEs upon direct perilymphatic application. These data reveal additional details about the rules of drug entry into the inner ear.

ST0114Using Mouse Behavioral Models for Assaying Vestibular Efferent Function

Anjali Sinha^1,2, Natalie B. Dang¹, Choongheon Lee¹, Joseph C. Holt^1,2,3

¹Department of Otolaryngology, University of Rochester, Rochester, NY, United States; ²Department of Neuroscience,University of Rochester, Rochester, NY, United States; ³Department of Pharmacology & Physiology,University of Rochester, Rochester, NY, United States

The efferent vestibular system (EVS) in mammals starts as a small number of bilateral, multipolar neurons in the dorsal brainstem. Axons of contralateral and ipsilateral vestibular efferent neurons (VENs) travel to multiple vestibular end organs on each side and extensively branch to give rise to an abundance of synaptic varicosities on hair cells and afferent terminals. While electrical stimulation of mammalian VENs in the laboratory setting profoundly modulates both the resting discharge and sensitivity of vestibular afferents, the functional framework, for how and when the mammalian EVS is employed under normal physiological conditions, is poorly understood. Pharmacological data regarding EVS actions in mice from our lab have characterized a number of cholinergic synaptic mechanisms that underlie the responses of vestibular afferents to efferent stimulation, including multiple muscarinic and nicotinic acetylcholine receptors. Some of our interest in performing vestibular studies in mice was having access to transgenic animals where these specific EVS synaptic mechanisms, implicated by our pharmacological data, have been disrupted. These mice are likely to present with distinct vestibular phenotypes that can be characterized in both electrophysiological and behavioral assays.

The utility of such an approach is highlighted by a number of recent observations made in mice where the alpha9 nicotinic acetylcholine receptor subunit (α9nAChR-KO) has been altered. Loss of functional α9nAChRs in α9nAChR-KO animals is associated with modifications in the response properties of vestibular afferents that likely give rise to changes in the vestibulo-ocular reflex (VOR), vestibular sensory evoked potential (VsEP), and vestibulo-autonomic pathways. For further insight into EVS function, we have recently employed a suite of behavioral assays that might reveal vestibular deficits in transgenic mice missing critical EVS signaling components. As our first test, we probed if α9nAChR-KO animals, relative to their controls (α9nAChR-WT), behave differently before and/or after being subjected to a provocative vestibular stimulus. Postural sway and center of pressure (COP) measurements were made on a miniature force plate from α9nAChR-WT and α9nAChR-KO mice before and after a 5-min rotation at 125 RPMs on an orbital shaker. Before stimulation, both groups of mice readily explored the confines of the force plate and exhibited comparable COP metrics. In the poststimulus period, however, α9AChR-KO mice displayed a striking reduction in their movement on the force plate which was often associated with a significant compression of postural sway space, bouts of immobilization along the corners and walls of the plate enclosure, and reduced point-to-point movements. Interestingly, older α9nAChR-KO, but not WT, animals exhibited similiar mobility phenotypes during the prestimulus period which may point to interactions among aging, stress, and vestibular function.

ST0115Thresholds for vestibular and cutaneous perception, and oculomotor response induced by galvanic vestibular stimulation

Thanh Tin Nguyen^1,2,4,*, Jin-Ju Kang^2,3,*, Sun-Young Oh^1,2,3

¹Jeonbuk National University College of Medicine, Jeonju, South Korea; ²Department of Neurology, Jeonbuk National University Hospital & School of Medicine, Jeonju, South Korea; ³Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, South Korea; ⁴Department of Pharmacology, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam

Objectives: The aim of this study was to detect the specific threshold intensities and response characteristics of galvanic vestibular stimulation (GVS) on vestibular (conscious) and cutaneous (detrimental) perception, as well as on oculomotor nystagmus (reflex).

Methods: These thresholds were determined concurrently, but separately, in 15 right-handed healthy subjects (aged 32.8 ± 6.76 years; 66.7% female) seated upright and wearing a Frenzel goggle while applying a direct current (DC) GVS with a cathode right and anode left paradigm using a two-step approach (gradual increasing followed by decreasing intensities).

Results: The mean vestibular threshold was 0.83 ± 0.45 mA and above the currents, dizziness of whirling sensation or falling tendency, which was more frequently directed to the clock-wise (33.3%) than the counter-clockwise (66.7%) rotation were induced. The mean cutaneous threshold was 0.88 ± 0.4 mA and the currents above which triggered mild tingling sensation on the cathode (66.7%), which was more frequent than on the anode (13.3%) (p=0.039, one-sample binomial test) or both sides (20%). The mean oculomotor threshold was 1.27 ± 0.53 mA and above the currents, right-beating horizontal (cathode) or clock-wise torsional nystagmus (77.3%), which was more frequent than the left-beat (anode) or counter clock-wise torsional nystagmus (26.7%) (p=0.035, one-sample binomial test) were induced. The oculomotor threshold was significantly lower than the vestibular threshold (p=0.023) and oculomotor threshold (p=0.036) (Mann-Whitney U test). Vestibular threshold was significantly higher in the male participants than the female (1.3 ± 0.45 mA vs. 0.6 ± 0.21 mA, p=0.022, independent t-test).

Conclusion: Our findings showed that the vestibular perception threshold was the highest sensitivity with the lowest level of current intensity compared to the oculomotor threshold. It implies that a strategy of lowering GVS current intensity, at the level of vestibular perception threshold, may prioritize eliciting beneficial vestibular stimulating effects while avoiding simultaneously detrimental effects such as oculomotor consequences.

ST0118How peripheral vestibular damage affects velocity storage

Amsal Madhani¹, Richard F. Lewis^1,2,3, Faisal Karmali^1,3

¹Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA; ²Department of Neurology, Harvard Medical School, Boston, MA; ³Department of Otolaryngology, Harvard Medical School, Boston, MA

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Velocity storage is a centrally-mediated mechanism that processes peripheral vestibular inputs. One prominent aspect of velocity storage is its effect on dynamic responses to yaw rotation. Specifically, when normal human subjects are accelerated to constant angular yaw velocity, horizontal eye movements and perceived angular velocity decay exponentially with a time constant circa 15-30 s, even though the input from the vestibular periphery decays much faster (~ 6 s). Peripheral vestibular damage causes a time constant reduction, which is useful for clinical diagnoses, but a mechanistic explanation for the relationship between vestibular damage and changes in these behavioral dynamics is lacking. It has been hypothesized that Bayesian optimization determines ideal velocity storage dynamics based on statistics of vestibular noise and experienced motion. Specifically, while a longer time constant would make the central estimate of angular head velocity closer to actual head motion, it may also result in the accumulation of neural noise which simultaneously degrades precision. Thus, the brain may balance these two effects by determining the time constant that optimizes behavior. We applied a Bayesian optimal Kalman filter to determine the ideal velocity storage time constant for unilateral damage. Predicted time constants were substantially lower than normal, similar to patients, and modeled interactions between age-related hair cell loss and peripheral damage. These results provide a mechanistic explanation for changes in velocity storage after peripheral damage. Results also suggested that even after peripheral damage, ipsilateral noise originating in the periphery or early central processing remains relevant in neurocomputations. Overall, our findings support the hypothesis that the brain optimizes velocity storage based on the vestibular signal-to-noise ratio.

ST0119Proposed Diagnostic Criteria for Definite Isolated Otolith Dysfunction

Myung-Whan Suh ¹, Toshihisa Murofushi²

¹Department of Otolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul, Korea; ²Department of Otolaryngology, Teikyo University School of Medicine Mizonokuchi Hospital, Kawasaki, Japan

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Background and objectives: Dizzy patients with abnormal otolith function tests, despite a normal caloric response, are defined as having specific (isolated) otolith organ dysfunction. This study was performed to compare the differences in clinical presentation between isolated otolith dysfunction (iOD) patients with lab- and Sx-based iOD group and lab-based iOD symptoms.

Subject and methods: The medical records of 23 iOD patients with normal caloric response but abnormal cervical vestibular evoked myogenic potential (VEMP), ocular VEMP, or subjective visual vertical were reviewed. Non-spinning vertigo was considered as otolith-related symptoms. The patients’ age, onset of dizziness, Numeric Rating Scale on the severity of dizziness, and concomitant vestibular disorders were analyzed.

Results: Patients in the lab-based iOD group were significantly older than those in the lab- and Sx-based iOD group. Known vestibular disorders were significantly more common in the lab-based iOD group (83.3%) compared to the lab- and Sx-based iOD group (18.2%). Despite the normal caloric response, catch-up saccade was found in the video head impulse test in more than half (54.5%) of the lab-based iOD group patients. There was no catch-up saccade in the lab- and Sx-based iOD group. There were no significant differences in gender ratio, frequency of dizziness attacks, and duration of illness.

Conclusions: We propose new definitions of definite iOD (lab- and Sx-based iOD) and probable iOD (lab- or Sx-based iOD). These new definitions may help researchers to identify patients who are more likely to have true iOD, and facilitate comparisons of results between different studies.

ST0124Stop-Gain Variant in the CENPP gene affecting Kinetochore assembly and Mitotic Progression segregates low frequency Sensorineural Hearing Loss

Paula Robles-Bolivar^1,2,3, Alberto Parra-Perez^1,2,3, Alba Escalera-Balsera^1,2,3, Alvaro Gallego-Martinez^1,2,3, Pablo Roman-Naranjo^1,2,3, Jose A. Lopez-Escamez^1,2,3,4

¹Otology & Neurotology Group CTS495, Department of Genomic Medicine, GENYO, Centre for Genomics and Oncological Research, Pfizer University of Granada Andalusian Regional Government, PTS, 18016 Granada, Spain; (P.R.-B.); (A.P.-P.); (A.E.-B.); (A.G.-M.); (P.R.-N.); (JA.L.-E.); ²Sensorineural Pathology Programme, Centro de Investigación Biomédica en Red en Enfermedades Raras, CIBERER, 28029 Madrid, Spain; ³Department of Otolaryngology, Instituto de Investigación Biosanitaria ibs.Granada, Hospital Universitario Virgen de las Nieves, Universidad de Granada, 18014 Granada, Spain; ⁴Division of Otolaryngology, Department of Surgery, University of Granada, 18011 Granada, Spain

Background: Low-frequency sensorineural hearing loss (SNHL) is a rare condition with a prevalence of 18 per 100.000 population. It is characterized by losses at tones under 1000Hz, accompanied by ear fullness and tinnitus, but without vertigo. When it overlaps with vestibular symptoms is considered an initial stage for Meniere disease (MD). To date, there is a total of 130 described genes underlying non-syndromic NSHL, but only five have been associated with low-tones phenotype, such as DIAPH1, WSF1, TNT, SLC26A4 or CCDC50, appearing with an autosomal dominant inheritance pattern. The purpose of this study is to determine the genetic cause of low frequency hearing loss diagnosed in four women from a Swiss family over three generations.

Methods: Four cases and one control were submitted to otological-audiometric examinations and exome sequencing from saliva samples. Bioinformatic data processing and subsequent candidate prioritization included variants with minor allele frequency (MAF)<0.001 in non-Finnish European population, pathogenic CADD score>20 and segregation in all affected members but absent in control. The coding genes from variants should also be expressed in inner ear.

Results: Audiological profile described an up-slopping configuration, with mild-moderate losses below 500Hz and progression to high frequencies over time, without tinnitus or vestibular symptoms. After prioritization process, the exome analysis pointed a novel non-sense variant in the Centromeric Protein P (CENP-P) gene, segregating in heterozygosis in cases. CENP-P is a subunit of CENPA-CAD (nucleosome distal complex), involved in assembly of kinetochore proteins, mitotic progression and chromosome segregation. RNA-seq studies revealed CENP-P expression in mouse inner ear in embryonic and postnatal stages, more in supporting than hair cells in both, the cochlea and the vestibular epithelia. The candidate variant (CENP-P,C283*) is classified as “Likely pathogenic” by ACMG guidelines, turning to “Pathogenic” when PP1 parameter (meaning co-segregation of these variant with phenotype in multiple family members) is manually activated. Variant generates a five amino truncation at the end of the protein, which it suggested to produce loss of electrostatic interactions by in sillico modelling, that could slightly alter the stability. Conservational analysis indicated limited conservation of altered residue between the top 50 sequences with higher identity with human CENP-P.

Conclusions: In conclusion, we present the gene coding for centromeric protein P (CENP-P) as a possible responsible for hearing loss at low frequencies. Consecutive advances in genetic defining this condition will enable us to improve its diagnosis, prognosis and treatment.

This project was partially funded by H2020-SC1-2019-848261 and the Swiss Schmieder-Bohrisch Foundation

ST0127Vestibular Adaptation Mitigates Unwanted Effects of Magnetic Vestibular Stimulation with Slow Bore Entry Velocity

Jacob M. Pogson^1,3, Dale C. Roberts¹, Jorge Otero-Milan^1,2, Ari Shemesh^4,5, David S. Zee¹, Bryan K. Ward¹

¹The Johns Hopkins University, Baltimore, United States; ²University of California Berkeley, United States; ³Royal Prince Alfred Hospital, Camperdown, Australia; ⁴Technion Israel Institute of Technology, Haifa, Israel; ⁵Hadassah Medical Center, Jerusalem, Israel

Magnetic Resonance Imaging (MRI) requires a powerful static electromagnetic field. Exposure of the inner ear to this magnetic field generates a magnetohydrodynamic Lorentz force in the endolymph, which pushes the cupulae of the lateral and superior semicircular canals, causing subjective vertigo and objective nystagmus. This force is proportional to magnetic field strength, so increases as subjects enter the MRI bore, remains constant within the bore, and then decreases on exit. However, for a typical 20 second entry duration, the nystagmus response usually increases to a peak over tens of seconds after entering the bore, and then exponentially reduces over seconds, minutes, and hours. The response is presumably mediated by a combination of central vestibular velocity storage and adaptation mechanisms. Here, we investigated if better matching the magnetic field entry time to the vestibular adaptation time-constants could mitigate the subjective and objective vestibular effects.

First, with Matlab SimuLink we built a three-axis mathematical model of the vestibular system which incorporates gravity, velocity storage (Tc=16sec), rotational feedback, and vestibular adaptation (Tc=100sec, Tc=1000sec). These parameters were set as determined by previous studies. We simulated nystagmus responses in the supine position with movement durations of 20, 120, and 300 seconds; the longer the entry and exit durations the lower the per and post peak slow-phase velocities (SPV).

Second, we collected data from 4 control subjects using a 7 Tesla MRI; 2 were naive to the stimulus. Binocular eye movements were recorded at 100 Hz, along with head orientation in the gravity and magnetic fields. Subjects were manually moved on the MRI bed to linearly increase or decrease the magnetic field over durations of 20, 120, and 300 seconds. As in our model simulations, longer entry and exit durations reduced the nystagmus peak SPV. All subjects reported that the 20 sec duration generated the most intense vertigo, all subjects reported some mild vestibular symptoms e.g., tilting without vertigo, for the 120s condition, whereas no subject reported any vestibular symptoms during the 300s condition.

In summary, the model successfully predicted that longer entry durations (120 and 300 secs) lower the peak SPV. Together, the model and data demonstrate a new method to mitigate the objective and subjective effects of MVS by taking advantage of vestibular adaptation. About 120s MRI entry and exit duration may be an ideal tradeoff between practical implementation and reduction of discomforting vestibular symptoms.

ST0129A Case of Virtual Reality In Visual Vertigo

Lennox, Amy; Morrow, Stacy

Vestibular rehabilitation (VRT) is used to manage the symptomatic manifestations of vestibular conditions. However often the outcomes of vestibular rehabilitation are limited by patient compliance and time constraints. The introduction of virtual reality technology can provide interesting interactions for patients thus encourage patients to actively participate in various repetitive rehabilitation exercises and overcoming the aforementioned barriers. Despite this, the efficacy of virtual reality for vestibular rehabilitation remains unclear. Preliminary evidence suggest the benefit of virtual- reality. Here, we present one case which will seek to address the utility of virtual reality.

The case demonstrates outcome measures pre and post vestibular rehabilitation utilising virtual reality technology in a patient who describes visual vertigo. The patient is a 29 year old male, referred to the service post head injury. The diagnosis was concluded as unilateral deficit as defined by video head impulse testing (vHIT) and Supression Head Impulse Paradigm test (SHIMP) results. The patient was initially seen 2 years post accident and sponteneous compensation/recovery had not occured. Subjective measures to monitor outcomes for rehabilitation included the Dizziness Handicap Inventory (DHI) and Visual Vertigo Analogue Scale (VVAS). The patient was asked to spend 5-10 minutes completing the tasks within virtual reality environment. The visually stimuating environment would increase to 20minutes after a period of desensitisation. After 9 months (time span due to travel restrictions and COVID19) the patients subjective scores and self reporting of visual vertigo increased significantly alongside the objective measurements. In vHIT Vestibulo-ocular reflex morphology was non-pathologocal with increased gains (increases of Lateral, 0.1, Posterior, 0.3 and Anterior, 0.2 in gain) and reduced asymmetry (Lateral, 9%, LARP, 35%, RALP, 26%). The Saccades of overt nature, become covert and gathered. Similarly with SHIMP the VOR morphology improved to mimic a non-pathological presentation, asymmetry significantly decreased and corrective saccades became gathered denoting a significantly reduced PR score (Left improvement, 14%, Right Improvement, 34%).

This case, albeit interesting, has limitations, predominantly due to the N number. However expansion of the study is in progress, inlusion criteria will be introducted, testing procedures randomly assigned and a statistically significant population will be recruited. The question of interest is whether virtual reality-based balance exercises performed during vestibular rehabilitation are superior to conventional balance exercises during vestibular rehabilitation in unilateral peripheral vestibular loss.

ST0130Apo-geotrophic nystagmus in a patient with cerebellar bleed

Hanaan Ashraf¹,Vishal Pawar²

¹Aster Al Rafa Polyclinic, International city Br. Dubai,U.A.E.; ²Aster Gardens Specialty clinic, Dubai, UAE

Target audience- Neurologists, Neurotologists, Otologists, Audio-vestibular physician

Theme

Introduction: Apogeotropic positional nystagmus is commonly seen with horizontal canal cupulolithiasis. However, it can be seen in some central lesions. The central causes include Vestibular migraine and tumours, stroke, demyelination, degenerative disorders involving the brainstem and cerebellum. It is imperative to differentiate it from benign paroxysmal positional vertigo (BPPV) involving the horizontal semicircular canal. We are presenting a case of apogeotrophic nystagmus seen in a patient with cerebellar nodular bleed.

Materials and Methods: The study was conducted at the outpatient dizziness unit, Aster Speciality Clinic, Dubai, UAE. All patients with positional vertigo underwent the Dix-Hallpike test (DHT), Head Roll test (HRT), Supine straight head extension (SSHE). We are presenting a case of cerebellar nodular haemorrhage manifesting positional vertigo and apo-geographic horizontal nystagmus.

Results: A 71 years gentleman, known diabetic and hypertensive, presented with positional vertigo for one month, each episode lasting 2-5 minutes. The patient was hospitalised with severe vertigo, imbalance, vomiting and headache one month ago in another facility and was diagnosed to have Intracerebellar bleed (Fig-1).

Fig-1)

CT brain showing left cerebellar hemorrhage involving the nodulus.

Cerebral angiography showed arteriovenous malformation. After discharge, he continued to have positional vertigo and nausea. Video-oculography (VOG) showed hypometric saccades, impaired smooth pursuit in horizontal and vertical planes. He had down-beating nystagmus in the dark suppressed on fixation. There were square wave jerks in central and horizontal gazes. HRT on the left showed right beating (apogeotrophic) nystagmus (Fig-2).

Fig-2)

Head roll test on left side showed right beating (apo-geotrophic) nystagmus

Discussion: The pathophysiological basis of the findings in our case is as follows.1) Positional nausea: It could be explained by the irritation of area postrema secondary to intraventricular haemorrhage or due to intracranial pressure changes. 2) Positional vertigo and nystagmus: Cerebellar nodulus is sensitive to gravity, and nodular lesions can cause positional vertigo and nystagmus, which explains the apogeotrophic nystagmus seen during the supine head roll test on the right in our patient. 3) Downbeating nystagmus suppressed by fixation: Nystagmus suppressed by fixation is usually seen in peripheral vestibular lesions. However, if flocculus or its connections are intact (as in our patient), the central nystagmus can get suppressed by fixation and mimic like peripheral. Hence, nystagmus seen without fixation does not exclude central aetiology.

Conclusion: Central pathologies should be considered in patients with apogeotrophic positional nystagmus. The pointers towards the central localisation include other central signs like saccadic abnormalities, impaired smooth pursuit, square wave jerks, down beating nystagmus. Hence thorough ocular motor testing is of paramount importance in the localisation of patients presenting with positional vertigo.

ST0131An explanation for individual variations in three-dimensional vestibular behavior

Chengqi Wang¹, Amsal Madhani¹, Faisal Karmali¹

¹Harvard Medical School / Massachusetts Eye and Ear, Boston, USA

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Many vestibular patients complain of inappropriate perceptions of three-dimensional motion, and subjectively there are differences even amongst vestibular-normal individuals. In this study, we used computational models to begin to develop hypotheses for the physiologic reasons for these variations. It is well accepted that the vestibular organs are imperfect, yet the brain is able to synthesizes a robust estimate of three-dimensional motion and orientation in most individuals. Computational models accurately describe these central processes. A growing body of computational and experimental evidence suggests that these central processes are adaptatively adjusted to minimize error – i.e., optimize in a Bayesian sense - based on the statistics of vestibular neural noise (i.e., variability) and experienced motion. For example, we have previously used this approach to study changes with aging and peripheral damage that occur in the yaw angular velocity. In this case, while a longer time constant would be advantageous because this would make the VOR accurate over a longer period of time, it has been argued that this would result in the accumulation of noise by the velocity storage mechanism, which would result in drift and make the VOR less precise. In this study, we extended these results to three-dimensional processing. The first behavior we studied was post-rotatory tilts - 45 deg tilts of the body following the cessation of constant-velocity upright yaw rotation. As in previous studies, we used perceptual thresholds and signal detection theory to estimate vestibular noise. We predicted responses that cover the normal range of human vestibular noise by using published data on the range of human thresholds. These predictions showed that changing only SCC noise resulted in substantial variations in estimates of angular velocity, linear acceleration and the direction of gravity. These inappropriate estimates of motion persisted for many seconds. The second behavior we studied was off-vertical axis rotation – constant-velocity rotation about an axis tilted relative to the vertical. These predictions showed that changing only SCC noise resulted in notable variations in estimates of angular velocity, minor variations in estimates of linear acceleration, and no variations in the estimates of gravity. These results provide a first step in explaining interindividual variations in three-dimensional vestibular responses and could lead to a better understanding of dizziness and vertigo.

Acknowledgements: Funded by NIH/NIDCD R01-DC018287.

FP0865Effect of Gentamicin Induced Vestibular Ablation on Quality of Life and Visual Sensitivity in Patients after the Vestibular Schwannoma Surgery

Zuzana Balatkova¹, Zdenek Cada¹, Silvie Hruba¹, Vladimir Koucky¹, Veronika Bandurova¹ Martin Komarc², Rudolf Cerny³, Jan Plzak¹

¹Department of Otorhinolaryngology and Head and Neck Surgery, 1st Faculty of Medicine Charles University in Prague and Motol University Hospital, Postgraduate Medical School; ²Department of Anthropomotorics and Methodology, Faculty of Physical Education and Sport, Charles University in Prague; ³Department of Neurology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital

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Objectives: Improvement of quality of life and minimizing of vestibular disorders postoperatively is one of the current goals in treatment of patients with vestibular schwannoma. Postoperative dizziness and postural instability are not the only problems, increased sensitivity to complex visual stimuli may persist in a long term and thus deteriorates the quality of life. Preoperative chemical vestibular ablation can reduce vestibular symptoms in patients after vestibular schwannoma resection. Our aim was to evaluate the effect of preoperative application of gentamicin on postoperative quality of life and visual sensitivity.

Methods: 0.5-1.0 mL of 40 mg/mL nonbuffered gentamicin in at least three intratympanic instillations in 11 patients was administered two months prior to the surgery. Head impulse and caloric tests confirmed reduction of vestibular function in all patients. The control group consisted of 21 patients. Quality of life in both groups was evaluated by the Glasgow Benefit Inventory (GBI), the Glasgow Health Status Inventory (GHSI) and the Dizziness Handicap Inventory questionnaires. The psychological profile was evaluated using GAD-7, Generalised Anxiety Disorder Assessment and Zung Self-Rating Depression Scale questionnaires. Visual symptoms and optokinetic sensation were evaluated by specific questionnaire developed by our team and by measuring preoperative and postoperative gains of optokinetic nystagmus with routine electronystagmography in both groups.

Results: There were no statistically significant differences between both groups with regards to the results of questionnaires. Patients who received preoperative gentamicin were less sensitive to visual stimulation (p <0.10). Many of them had significantly higher gain in the optokinetic nystagmus than the control group. Significant difference of psychological profile survey was observed between the groups.

Conclusions: Preoperative gentamicin induced vestibular ablation helps to lower the level of anxiety in patients and improves their general postoperative status. Pre-treatment also helps to decrease the sensitivity to complex visual stimulation and combined sensory perception.

Study registration number is NCT03638310.

FP0866Does the pre-treament by chemical vestibular ablation decrease patients’sensitivity to optokinetic and optic flow stimulation after vestibular schwannoma retrosigmoid suboccipital resection?

Zdenek Cada¹, Zuzana Balatková¹, Rudolf Cerný², Ondrej Cakrt³, Jan Plzák¹

¹Department of Otorhinolaryngology and Head and Neck Surgery, 1st Faculty of Medicine Charles University in Prague and Motol University Hospital, Postgraduate Medical School; ²Department of Neurology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital; ³Department of Rehabilitation and Sports Medicine, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital

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Objectives: Surgical removal of vestibular schwannoma causes acute vestibular symptoms, including postoperative vertigo, oscillopsia. Some patients are also more sensitive to optokinetic stimulation (optic flow). Preoperative chemical vestibular ablation can reduce vestibular symptoms postoperatively.The goal of two presented studies was to determine whether chemical vestibular prehabituation influences the patients’sensitivity to optokinetic stimulation.

Methods: In both studies 0.5-1.0 mL of 40 mg/mL nonbuffered gentamicin was injected preoperatively transtympanically in 21 patients (study group). Head impulse and caloric tests confirmed reduction of vestibular function in all patients. The control group consisted of 31 patients. Visual symptoms and optokinetic sensation were evaluated using a specific questionnaire developed by our team and by measuring optokinetic gain preoperatively and postoperatively in both groups. The psychological profile was evaluated in both groups by using the validated questionnaires for depression and anxiety.

Results: Gentamicin group was less sensitive to visual stimulation in both studies (p <0.05, p <0.10). Already preoperatively had the majority in the study group a significantly higher gain in the optokinetic nystagmus measurement than the control group.

Conclusion: Patients who received preoperative gentamicin were more resilient to optokinetic and optic flow stimulation.

This trial is registered with clinical study registration number NCT02963896.

FP0870Safe Stability! The importance of multisensory input for balance control in people with intellectual disabilities: a pilot study.

Laura Leyssens¹, Ruth Van Hecke¹, Karlien Moons¹, Sofie Luypaert¹, Melina Willems^2,3, Maya Danneels¹, Sarie Martens¹, Cleo Dhondt⁴, Leen Maes^1,5

¹Department of Rehabilitation Sciences, University of Ghent, Belgium; ²Artevelde University of Applied Sciences, Ghent, Belgium; ³Special Olympics International; ⁴Department of Head and Skin, University of Ghent, Belgium; ⁵Department of Ear, Nose and Throat, University Hospital of Ghent, Belgium

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Background. Substantial evidence indicates that persons with intellectual disabilities (ID) are more susceptible for sensory impairments (e.g. hearing loss) and often experience motor problems (e.g. postural instability, frequent falling). Despite the anatomical and physiological proximity between the hearing and vestibular organ, and the well-established role of the vestibular system in several gross motor skills, data on the (peripheral) vestibular function is scarce in this population. This urged us to estimate the occurrence and characteristics of vestibular dysfunctions in the ID population, by applying a vestibular screening in a heterogeneous group of adult persons with ID and an age- and gender-weighted control group. Additionally, in a subgroup of the participants with ID, the auditory, visual, and postural balance function was evaluated in addition to the vestibular function, to explore the impact of (multi)sensory dysfunctions on the postural balance performance.

Methods. 45 adults with ID (18-61 years) participated to a vestibular screening protocol (cVEMP & vHIT) at the National Games of Special Olympics Belgium, of which 30 athletes (18-61 years) also completed an auditory (sequential protocol consisting of DPOAEs, tympanometry, and audiometry), visual (SVA), and postural balance evaluation (RS and SLS on a force platform, mFRT, and TUGT). Additionally, an age- and gender-weighted control group of 42 adults without ID (19-58 years) was subjected to the same vestibular screening protocol, of which 25 subjects (19-59 years) also underwent the postural balance evaluation.

Results. Compared to the control group, the occurrence of abnormal cVEMP and vHIT responses was significantly higher in the ID group, and the ID subjects performed significantly worse and/or showed more body sway for all balance tasks except the TUGT. Within the ID group, a significant positive correlation was observed between the number of failed sensory screening items and the number of failed balance tasks.

Conclusion. This study suggests an increased prevalence of peripheral vestibular deficits and postural balance problems in people with ID relative to the general population, and significant involvement of peripheral sensorial deficits in these postural balance dysfunctions.

Abbreviations.

ID=intellectual disabilities

cVEMP = cervical vestibular evoked myogenic potentials

vHIT = video head impulse test

DPOAEs = distortion product otoacoustic emissions

SVA = static visual acuity

RS = Romberg stance

SLS = single leg stance

mFRT = modified functional reach test

TUGT = timed-up-and-go test

FP0873A New Spin on Sensory Organization Testing

Colin R. Grove¹, G. Mark Pyle², Bryan C. Heiderscheit³, Kristin E. Caldera³, Scott J. Hetzel⁴, Susan L. Whitney⁵

Johns Hopkins University¹; University of Wisconsin-Madison: Departments of Surgery²; Orthopedics and Rehabilitation³; and Biostatistics⁴; University of Pittsburgh: Department of Physical Therapy⁵

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Background: The Sensory Organization Test (SOT) is a test of balance in vestibular-impaired persons. Historically, despite excellent sensitivity, its diagnostic value has been diminished by poor specificity. Further, there is lingering uncertainty regarding what this test measures since performance on the SOT has not been strongly correlated with vestibular function tests, patient-reported outcomes, functional balance tests, or gait. Despite its shortcomings, the SOT is frequently used as an outcome in vestibular rehabilitation. Recently, the Bertec Balance Advantage (BBA) computerized dynamic posturography device was developed which includes a new version of the SOT (BBA-SOT). The protocol for the BBA-SOT is similar to the SOT; however, the new test is implemented using high-precision force plates and a virtual reality projection system. Given these enhancements, the psychometric properties of the BBA-SOT must be explored. The aims of this study were to examine the criterion and convergent validity of the BBA-SOT.

Methods: A total of 34 adults, 17 vestibular-impaired (9 women, age 61.1; sd 10.2) and 17 healthy (13 women, age 39.3; sd 11.2) participated in this study. Criterion validity was evaluated by calculating the area under the curve (AUC) using receiver operator characteristic analysis. We assessed convergent validity by calculating Spearman’s correlation coefficient between overall performance on the BBA-SOT and the Activities-specific Balance Confidence (ABC) scale, Dizziness Handicap Inventory (DHI), non-instrumented Dynamic Visual Acuity Test (NI-DVAT), Five-times Sit to Stand Test (FTSTST), Functional Gait Assessment (FGA), and an instrumented 2-minute walk test (i2MWT).

Results: The AUC (95% CI) for the BBA-SOT composite score was 0.95 (0.88,1). The correlations (95% CI) between the BBA-SOT composite score and other specific outcomes of interest were: 0.71 (0.49, 0.85) (ABC average score), -0.8 (-0.9, -0.64) (DHI total score), -0.69 (-0.83, -0.46) (degradation in visual acuity, horizontal NI-DVAT), -0.69 (-0.83, -0.45) (degradation in visual acuity, vertical NI-DVAT), -0.59 (-0.77, -0.31) (FTSTST time), 0.73 (0.52, 0.86) (FGA total score), as well as 0.51 (0.18, 0.74) (gait speed), -0.61 (-0.8, -0.32) (terminal double support, left), -0.44 (-0.69, -0.1) (terminal double support, right), 0.63 (0.36, 0.81) (turn velocity), and -0.61 (-0.8, -0.32) (turn duration) from the i2MWT.

Conclusions: The BBA-SOT composite score has excellent ability to discriminate between healthy and vestibular-impaired adults. Overall performance on the BBA-SOT is moderately to strongly correlated with measures of balance-related confidence, dizziness-related perceived handicap, dynamic visual acuity, balance, and gait. These findings support the use of the BBA-SOT as a valid balance test.

FP0877A Link Between Posturography and Vestibulo-Ocular Reflex

Manuel Oliva-Domínguez¹; María Dolores Aguilar-Conde²; Juan Bartual-Magro³; Juan Bartual-Pastor⁴

¹Hospital Costa del Sol (Marbella, Spain); ²Hospital Virgen de la Victoria (Málaga, Spain); ³Hospital Virgen de la Cocha (Zamora, Spain); ⁴Chairman of Otolaryngology, retired (Cádiz, Spain)

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Our study wil connect the vestíbulo-ocular reflex gain to the performance in posturographic tests.

Material and Methods: all patients included in this study underwent a vHIT in the horizontal plane, recording the instantaneous gain at 60 msec. To get a result regardless of the affected side, we added the results to the right and left manoeuvres in the same patient.

Posturographics tests were recorded by means of a triaxial accelerometer device attached to the patient’s head. This device records the acceleration exerted in every spatial plane. Through trigonometry, we can calculate the angle made up in every plane. Eventually, 90% of the amplitude of the angle change was calculated. To get a single representative value, the equation 2*Pitch + Roll + Yaw was applied.

All patients underwent the mCTSIB protocol plus Unterberger-Fukuda test, recording 20 secs for every test.

Next, we applied a linear regression fit model, pairing the oscillation amplitudes in posturography with the vestíbulo-ocular reflex gain, working out the regression coefficient and statistic significance by means of p value. Significance was set up to 0.05

In the end, we also checked out the relationship between vHIT and oscillations in every spatial plane, if a significant p value is found in a test

RESULTS: our series includes 165 patients, mean age 56.85 years, 40% men and 60% women. Results in mCTSIB are, regression coefficient and p value, -0.02 and 0.56 (s2eo), -0.03 and 0.54 (s2ec), -0.04 and 0.43 (s2eof), -0.08 and 0.31 (s2ecf). Unterberger-Fukuda test, however yielded a coefficient of -0.28 and p value 0.000043.

Next, linear fit model was applied, as detailed before, for Unterberger-Fukuda test in every spatial plane. Results were, coefficient and p value: -0.05 and 1.27e-06 (Roll), -0.03 and 0.001 (Pitch), -0.16 and 0.005 (Yaw)

CONCLUSIONS: Unterberger-Fukuda test is the only posturographic test were significant statistical results were found, showing that head oscillations increase as vestíbulo-ocular reflex gain decreases. This link is more pronounced in the yaw plane, which meets the plane where the vHIT was performed

FP0882Including an Otoneurologist in the infectious endocarditis protocol

Angel Batuecas Caletrío, Sofía Ferreira Cendón, Maria José Fernandez Nava, María Gil Melcón, Hortensia Sánchez Gómez

Otoneurology unit. ENT Department. IBSAL. University Hospital of Salamanca. Salamanca. Spain.

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POSTER: Infectious endocarditis is a serious infection in the heart cavities. Systemic gentamicin is the first choice treatment in most protocols. The vestibulotoxic effect of gentamicin is well demonstrated. We studied the importance of including the vestibular tests in the assistance protocol of patients treated of infective endocarditis with systemic gentamicin.

Methods: We studied two groups of patients treated for their infectious endocarditis with systemic gentamicin. The first group before including an otoneurologist in the assitance protocol and the second group after including it.

We analyze the time from the beginning of the treatment until the onset of symptoms, the time to be assessed by an otoneurologist, the vestibular damage produced, the presence or not of oscillopsia and the recovery of the damage.

Results: 29 patients were included in the study. 13 in group 1 and 16 in group 2. The paceintes of group 1 took 65 days to be assessed by an otoneurologist and those of group 2 only 2. The average VOR gain measured through vHIT was 0.39 and 0.44 in patients in group 1 and 0.64 and 0.71 in group 2. 5/13 patients in group 1 suffered from oscillopsia while in group 2 only 3/16.

Conclusions: Since the effect of systemic Gentamicin in the vestibule is known and that this mediation is of first choice in the treatment of infective endocarditis, an otoneurological assessment should be included in these patients to prevent severe damage to vestibular function.

FP0883Skull VIbration induced nystagmus: optimizing tests

Angel Batuecas Caletrío¹, Sofía Ferreira Cendón¹, Maria José Fernandez Nava¹, Juan Carlos del Pozo de Dios¹, Hortensia Sánchez Gómez¹, Vanessa Pérez Guillén²

¹Otoneurology unit. ENT Department. IBSAL. University Hospital of Salamanca. Salamanca. Spain; ²Otoneurology unit. ENT Department. Hospital universitario La Fe. Valencia. Spain.

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POSTER: Skull vibration induced nystagmus (SVIN) is a useful and easy resource that provides great information about vestibular function.

The relationship of the findings in the SVIN with other vestibular tests has already been studied. But the relationship between the SVIN findings and the findings in the Video Head impulse test is unknown.

Methods: We analyze and compare the findings in 63 patients with vestibular neuritis in both SVIN and vHIT. Patients were studied at least six months after suffering vestibular neuritis.

Results: 38 men and 25 women were included in the study. 33 right and 30 left. In all cases the nystagmus was directed towards the healthy side.

The stimulation frequency that achieved a higher percentage of SVIN appearance was 100Hz. A moderate correlation was obtained between the appearance of SVIN and the gain asymmetry measured through vHIT. The SVIN appeared in all cases in which there was a difference between the gains of the healthy side and the affected side above 0.31

Conclusions: In cases of vestibular neuritis, the presence of a positive SVIN correlates with a large asymmetry in the vestibuloocular reflex gains. The SVIN is a useful test for the location of the diseased side in cases of vestibular neuritis.

FP0884Advantages of VHIT in the evaluation of recently postoperated patients

Zenaida Piñeiro-Aguín¹, Albert Pujol-Olmo², Olga Ferrer-Andino³

¹Parc de Salut Mar – Hospital del Mar. Barcelona; ²Hospital de la Santa Creu i Sant Pau. Barcelona; ³Pars Sanitari Sant Joan de Deu. Sant Boi de Llobregat

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Advantages of VHIT in the evaluation of recently postoperated patients

Introduction: After middle ear surgery, especially Stapedectomy, acute episodes of vertigo and vestibular syndromes may occur. From the introduction of VHIT, these patients can be evaluated 24 hours after the intervention or even immediately if the patient has symptoms. The precision in the involvement of the VOR gives us a topographic diagnostic.

Material and methods: Over a period of three years (2016 - 2019), 16 patients with postoperative vestibular symptoms were reviewed. Mainly stapedectomy (9 cases) and myringoplasty (7 cases) performing VHIT initially, at 3 months and one year after the intervention, if the initial VHIT was pathological. In 5 patients, vestibular pathology with alteration of the VOR was found and in two cases the examination was normalized. In two of the cases the affectation was due to the inferior vestibular nerve only, ipsilateral to the surgery.

Results and Discussion: In the 5 pathological cases, an improvement of the dispersion in the PR index was observed, well correlated with the patient’s clinic that improves the symptomatology as the saccades are grouped. In accordance with the literature, VHIT is a good predictor of clinical improvement in postoperative patients. With this method, the function of the vestibule can be evaluated even with the healing eardrum and without applying water or air to the surgical bed.

Conclusions: VHIT is an effective and safe method for the evaluation of patients after middle ear surgery. The speed and simplicity of the method gives us security and precision in the diagnosis of possible postoperative hipofunctions of the vestibule. In future work, the vestibular function must be evaluated before and after surgery, mainly in Otosclerosis.

FP0885Value of targeted bedside neuro-otological examination in the acutely dizzy patient

Alexander A. Tarnutzer^1,2, Daniel Gold³, Zheyu Wang^4,5, Karen A. Robinson⁶, Jonathan A. Edlow^7,8, Terry D. Fife^9,10, Jorge C. Kattah¹¹, Kevin A. Kerber¹², Georgios Mantokoudis¹³, Elizabeth Marsh³, Ali S. Saber Tehrani³, David S. Zee³, David E. Newman-Toker³

¹Cantonal Hospital of Baden, Baden, Switzerland; ²Faculty of Medicine, University of Zurich, Zurich, Switzerland; ³Johns Hopkins University School of Medicine, Department of Neurology, Baltimore, MD; ⁴Division of Biostatistics and Bioinformatics, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine; ⁵Johns Hopkins Bloomberg School of Public Health, Department of Biostatistics, Baltimore, MD; ⁶Johns Hopkins University School of Medicine, Department of Medicine, Baltimore, MD; ⁷Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA; ⁸Harvard Medical School, Boston, MA; ⁹Department of Neurology, Barrow Neurological Institute, Phoenix, AZ; ¹⁰Department of Neurology, University of Arizona College of Medicine, Phoenix, AZ; ¹¹University of Illinois College of Medicine. Peoria, IL; ¹²Department of Neurology, Health Services Research Program, University of Michigan, Ann Arbor, MI; ¹³Department of Otorhinolaryngology, Head and Neck Surgery, lnselspital, Bern University Hospital, University of Bern, Bern, Switzerland

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Acute dizziness/vertigo is usually due to benign inner ear causes but occasionally due to dangerous neurologic causes, particularly stroke. Because symptoms and signs are superficially similar, misdiagnosis is a serious concern and overuse of diagnostic tests is common. Here we assessed the accuracy of symptoms and physical examination findings in acutely dizzy adults to identify those with central neurologic causes, particularly stroke. We performed a systematic search of MEDLINE and Embase (1980-2016) to identify studies reporting on the diagnostic accuracy of bedside vestibular tests in acutely dizzy patients. Studies were included that measured the performance of bedside findings for identifying peripheral versus central causes using a reference standard of neuroimaging (magnetic resonance imaging with diffusion weighted images [MRI-DWI]). Studies reporting on either episodic, positionally-triggered vertigo or acute, prolonged vertigo were screened. 3722 unique articles were identified, of which 18 met inclusion criteria. Two authors independently performed critical appraisal and data extraction. Sensitivity, specificity and likelihood ratios were calculated for individual physical examination findings for acute vertigo. Six studies reported preliminary data. No high-quality studies differentiating benign paroxysmal positional vertigo from central positional vertigo in patients with positionally-triggered episodes were identified. For the acute vestibular syndrome (AVS), 12 studies (prospective=6; retrospective=6) with a total of 607 patients were included with a range of 8 to 191 patients per study. 415 patients had central causes (with 373 ischemic strokes). Eye movement abnormalities and truncal instability/gait disturbance were the clinical signs with the highest diagnostic value to distinguish peripheral and central causes of AVS. A three-step bedside testing battery “H.I.N.T.S.” (Head Impulse, Nystagmus, Test of Skew) had excellent diagnostic properties when performed by specialists (sensitivity 0.97 [0.94-0.99, 95%CI]; specificity 0.91 [0.87-0.95]). Severe (grade 3) truncal/gait ataxia had high specificity (0.96 [0.93-0.99]) but low sensitivity (0.45 [0.37-0.52]). Early MRI-DWI (i.e., within the first 24-48 hours) was able to be assessed in 124 patients and was falsely negative in one of five stroke patients (sensitivity 0.79 [0.72-0.86]). In AVS, eye movement examination by specialists can differentiate peripheral from central causes and appears to have higher diagnostic accuracy for stroke than even MRI-DWI in the first 48 hours after onset of symptoms. Future studies should design and evaluate methods to disseminate and implement these techniques to frontline clinical practice.

FP0889The Dizziness Handicap Inventory as a predictor of sick leave

Mari Kalland Knapstad^1,2, Frederik Kragerud Goplen^1,3, Stein Helge Glad Nordahl^1,3, Jan Erik Berge^1,3

¹Norwegian National Advisory Unit on Vestibular Disorders, Department of Otorhinolaryngology & Head and Neck Surgery, Haukeland University Hospital, Bergen, Norway; ²Department of Health and Functioning, Western Norway University of Applied Sciences, Bergen, Norway; ³University of Bergen, Department of Clinical Medicine, University of Bergen, Bergen, Norway

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Background: Dizziness is a common complaint in the adult population and is associated with reduced quality of life, psychological comorbidity and financial burden for both patients and health care systems. The Dizziness handicap inventory (DHI) is a commonly used questionnaire for assessing the self-perceived handicap in dizzy patients. The aim of this study was to examine the association between the DHI and sick leave.

Methods: This was a cross-sectional study conducted at an otolaryngology clinic. We included a total of 238 patients between 18 – 67 years old, referred for either balance or dizziness symptoms during a 1-year period. Sick leave the last 30 days was categorized as no sick leave, <50% sick leave, >50% sick leave or 100% sick leave. The association between sick leave over the last 30 days and DHI was examined with binary and ordinal logistic regression analysis. The hospital anxiety and depression scale (HADS), Health-related quality of life (RAND-12), diagnosis, duration of dizziness, age and gender were used as covariates.

Results: A total of 63 males (mean age 46.4 (SD 10.8)) and 175 females (45.4 (SD 12.6)) were included, with 46% diagnosed with a peripheral vestibular disorder. Adjusting for covariates, the logistic regression analysis showed that a 10-point increase on DHI (range: 0 – 100) was associated with being on sick leave (yes/no) the last 30 days (OR: 1.50, 95% CI: 1.25 – 1.90, p <0.001). Categorizing sick leave status, using no absence as base outcome, a 10-point increase in DHI-score was associated with a higher degree of sickness absence in the adjusted analysis (OR: 1.50, 95% CI: 1.25 – 1.80, p < 0.001).

Conclusion: In this study, we found that a higher score on DHI is associated with the degree of sick leave the last 30 days, even after adjusting for health-related quality of life, anxiety and depression symptoms. These results indicate the clinical usefulness of the DHI as a possible predictor of sick leave in patients with dizziness.

FP0891Development of an Application for Vestibular Rehabilitation for Older Adults Informed by Clinical Care

Linda D’Silva², Karen Skop³, Michael Rossi¹, Jeremy Martin¹, Katherine Marschner¹, Nathan T. Pickle¹, Timothy Zehnbauer¹, Paulien E. Roos¹

¹CFD Research Corporation, Huntsville AL, USA; ²University of Kansas Medical Center, Kansas City, KA; ³: Jame Haley VA Hospital, Tampa, FL

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Background: Almost half of people over the age of 60 experience dizziness. Vestibular rehabilitation has been proven effective in reducing dizziness and falls. However, adherence to exercise programs remains a major problem and can be below 50%. Clinicians typically rely on patient self-reporting to assess adherence and are often unsure if exercises were performed correctly at-home. Therefore, this research aimed to develop an app with gaming elements and remote monitoring to improve adherence of older adults to gaze stabilization and balance exercises.

Methods: Games for VORx1, two target, and two different balance exercises (weight shift and single leg) were developed and incorporated in an app. The app allows exercise prescription and remote monitoring through a web portal. A clinician informed design was used when five physical therapists were asked identical questions about the exercises they would like to see represented in the app, the duration, and frequency of exercises. The app provides exercises in the form of games that are controlled by an Inertial Measurement Unit (IMU) sensor placed on the head or sacrum. The app was tested on ten healthy females aged 60-74 years (69.1± 5.1 years). Participants completed gaze stabilization and balance exercises using the app and provided feedback on use intention, ease of use, usefulness and enjoyment using questionnaires and open-ended questions.

Results: for 2 out of 4 games, 9 out of 10 subjects showed high enjoyment. All 10 subjects responded they would find the app easy to use, found it useful to do exercises, would use it again if they had dizziness issues, and felt motivated when playing the games. 3 out of 10 subjects felt frustrated and/or worried while using the app. The open-ended questions showed this was due to confusion on game instructions. Subjects liked the colors and graphics in the games for the different exercise levels.

Conclusions: This study demonstrated that an app for vestibular rehabilitation with gaming elements was found enjoyable and useful by older adults and was easy to use. It highlighted areas that may cause frustration and need improvement. On the longer term the app may increase adherence of older adults to vestibular rehabilitation exercises due to the game design, remote monitoring, and feedback.

This research was supported by the NIDCD of the NIH (Award R44DC017408). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

FP0892Influence of Testing and Measurement Variables on High Frequency Visuo-Vestibular Interaction and VOR Suppression Quantified Clinical Tests.

Maria Montserrat Soriano-Reixach, Elisabeth Ninchritz-Becerra, Izaskun Thomas-Arrizabalaga, Ariadna Valldeperes-Vilanova, Jorge Rey-Martinez, Xabier Altuna.

Neurotology Unit. ENT Department. Hospital Universitario Donostia. San Sebastián - Donostia. Spain.

Quantified VVOR and VORS tests has been recently added to available clinical vestibular tests. But despite clinical validity of these quantified tests that appear to have an increasing clinical interest, the influence of most of clinical testing method and mathematical analysis variables are not well defined for clinical testing purposes. The objective of this study is to investigate the main influence of some testing and analysis variables on clinical quantified VVOR and VORS results. For that, a prospective observational clinical study on 19 heathy patients has been realized. Every participant was examined with quantified visually enhanced vestibular-ocular reflex test and vestibulo-ocular reflex suppression test. The results of the study are the follow ones: a significant statistical difference between the three VVOR, VORS with no reinforce paradigm and VORS reinforce paradigm tests was found for a mean gain values of 0.91 ± 0.09 and 0.6 ± 0.15 and 0.57 ± 0.16 respectively (p < 0.001). Optimized linear model showed a significant influence of frequency on gain values for reinforced VORS and non-reinforced VORS test (p = 0.01 and p = 0.004, respectively). Attending to gain analysis method, statistical significant differences were found depending on the short time sample location of the records for initial location of VVOR test (p < 0.006) and final location of VORS with reinforced paradigm test (p < 0.023). In conclusion, there are significant differences for gain values according to VVOR and VORS testing as effect of VOR suppression. Head movement frequency is a significant factor that affect to the gain values especially for VORS testing. Also, for VORS testing there is a significant effect of participant concentration on testing task for suppression gain values. When a short time window sample is considered for VVOR and VORS testing, middle located time samples appears to be most adequate for both tests.

FP0898Psychometric properties of the abbreviated Dizziness Handicap Inventory (DHI-S) in general practice

Vincent A. van Vugt¹, Henrica C.W. de Vet ², Johannes C. van der Wouden¹, Henk C. P. M. van Weert¹, Henriëtte E. van der Horst¹, Otto R. Maarsingh¹

¹Department of general practice, Amsterdam UMC, Amsterdam Public Health, The Netherlands; ²Department of epidemiology and biostatistics, Amsterdam UMC, Amsterdam Public Health, The Netherlands.

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Background: The 25-item Dizziness Handicap Inventory (DHI) is worldwide the most used questionnaire to assess impairment due to vestibular symptoms and measure treatment success. However, the DHI’s length limits applicability in daily clinical practice. The abbreviated 10-item DHI-S is a promising alternative. The aim of this study was to assess the validity, reliability, responsiveness, optimal cut-off point for substantial impairment and the minimally important change of the DHI-S in general practice.

Methods: We performed a psychometric evaluation of the DHI-S questionnaire in general practice. In a prospective cohort study 415 adults with vestibular symptoms (aged = 65 years) were diagnosed with regard to subtype(s) and underlying cause(s) after a full diagnostic workup. Participants filled out the 25-item DHI at baseline, and one week, six months and ten years follow-up. The DHI answers were used to calculate DHI-S scores. Validity was assessed by criterion validity (Pearson’s r) at each measurement. Longitudinal measurements were used for test-retest reliability (intraclass correlation coefficient) and responsiveness (Pearson’s r). We used ROC curve analyses to determine optimal DHI-S cut-off points for substantial impairment (=30 DHI) and minimally important change (>11 DHI).

Results: The DHI-S demonstrated excellent criterion validity (r = 0.93-0.96), test-retest reliability (ICC =0.86) and responsiveness (r = 0.89). The DHI-S reliably distinguished substantial impairment and identified minimally important change, with optimal DHI-S cut-off scores of =12 points and >5 points, respectively.

Conclusion: The DHI-S is a valid, reliable, and responsive questionnaire that can replace the DHI in general practice. The DHI-S could potentially become a valuable tool in the management of patients with vestibular symptoms.

FP0901The Resilience of the Inner Ear - Vestibular and Audiometric Results after Transmastoidal Plugging of a Semicircular Canal

Joost J. A. Stultiens¹, Nils Guinand², Vincent van Rompaey³, Angélica Pérez Fornos², Henricus P.M. Kunst¹, Hermanus Kingma¹, Raymond van de Berg¹

¹Department of Otorhinolaryngology & Head and Neck Surgery, School for Mental Health and Neuroscience, Faculty of Health Medicine and Life Sciences, Maastricht University Medical Center, Maastricht, The Netherlands; ²Division of Otorhinolaryngology and Head-and-Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland; ³Department of Otorhinolaryngology and Head & Neck Surgery, Faculty of Medicine and Health Sciences, Antwerp University Hospital, Antwerp, Belgium.

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Background: Currently, only few indications exist for surgical intervention in peripheral vestibular disorders. However, some patients are not sufficiently treated by conservative care and the pathophysiology provides options for surgical therapy. Certain patients with intractable benign paroxysmal positional vertigo or superior canal dehiscence syndrome may opt for plugging of the affected semicircular canal to relieve them from disabling symptoms. However, structured data of the impact of this procedure on vestibular function and hearing is lacking. The aim of the current study is to assess evolution of vestibular and audiometric function after transmastoidal plugging of a semicircular canal.

Methods: Patients undergoing transmastoidal plugging of a semicircular canal for superior semicircular canal dehiscence syndrome or for benign paroxysmal positional vertigo were selected and underwent pre- and postoperative assessment of vestibular and audiometric function. This assessment consisted of bithermal caloric irrigation test, video Head Impulse Testing, cervical and ocular vestibular evoked myogenic potentials, and pure tone audiometry. Patients were tested postoperatively at one week, two months and six months follow up. A CT scan was performed six months postoperatively.

Results: Low-frequency vestibulo-ocular reflex (VOR) response declined initially in 6/6 patients and high-frequency VOR gain declined in 4/6 patients. Postoperative VOR response recovered to >60% in 4/6 patients and high-frequency VOR gain was restored to =86% of the preoperative value in 5/6 patients for both ipsilateral non-plugged semicircular canals. Four patients preserved cervical and ocular VEMP responses. Bone conduction hearing deteriorated in 3/6 patients, but recovered within six months postoperatively, although one patient had a persistent loss of 15 dB at the 8 kHz threshold.

Conclusion: Impact of semicircular canal plugging varies widely between patients. It seems that ipsilateral vestibular function decreases postoperatively in all patients and auditory function decreases in some patients. However, several patients show almost full restoration of the function of the two non-plugged semicircular canals and auditory function within six months postoperatively. Therefore timing of the postoperative assessment is essential for outcome assessment. These results are important for counseling of patients undergoing plugging of a semicircular canal and for the development and implementation of other procedures involving surgery of the semicircular canal, such as vestibular implantation.

FP0905SHIMP versus HIMP in diagnosing patients with Bilateral Vestibulopathy

T.S. van Dooren^1,4, B. Dobbels⁸*, F.M.P. Lucieer¹*, D. Starkov^1,2, A.M.L. Janssen^4,5, N. Guinand^1,6, A. Pérez Fornos⁶, V. Van Rompaey^7,8, H. Kingma^1,2, R. van de Berg^1,2* both authors share equal contribution

¹Division of Balance Disorders, Department of Otorhinolaryngology and Head and Neck Surgery, Maastricht University Medical Centre, Maastricht, Netherlands; ²Faculty of Physics, Tomsk State Research University, Tomsk, Russia; ³Faculty of Health, Medicine and Life Sciences, University of Maastricht, Maastricht, Netherlands; ⁴Department of ENT/Audiology, School for Mental Health and Neuroscience (MHENS), Maastricht University Medical Centre, Maastricht, The Netherlands; ⁵Department of Methodology and Statistics, Care and Public Health Research Institute (CAPHRI), Maastricht University, Maastricht, The Netherlands; ⁶Service of Otorhinolaryngology Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland; ⁷Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; ⁸Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital, Edegem, Belgium.

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Introduction. A horizontal vestibulo-ocular reflex gain (VOR gain) of < 0.6, measured by the video head impulse test (VHIT or HIMP), is one of the diagnostic criteria for bilateral vestibulopathy (BV) according to the Báràny Society. However, VOR gain calculations can be influenced by compensatory saccades during the head impulse (i.e. covert saccades). To overcome this issue, eye movements are desaccaded by the HIMP paradigm. An alternative is the Suppression Head Impulse test (SHIMP), since it reduces covert saccades in BV patients which make VOR gain calculations probably more reliable. The goal of this study was to determine the clinical consequences of using SHIMP instead of HIMP when diagnosing BV.

Methods. This study comprised 98 BV patients (diagnosed according to the Báràny criteria in Antwerp University Hospital and Maastricht University Medical Centre). They were sequentially tested with HIMP and SHIMP paradigm (Otometrics). Artefacts were removed from all impulses. A custom-made algorithm was used for saccade detection. VOR gain (area under the curve) was calculated on the artefact free impulses. Both VOR gain and the frequency of covert saccades were compared between the two tests. Lastly, the agreement on BV diagnosis (VOR gain < 0.6 or not) between the two paradigms (HIMP and SHIMP) was assessed.

Preliminary results. BV patients in this study showed significantly fewer covert saccades during SHIMP, compared to HIMP (p=0.001 and p=0.006 for rightwards and leftwards head impulses respectively). VOR gain differed statistically significant between SHIMP and HIMP for both rightwards and leftwards head impulses (p < 0.000), where mean VOR gain during SHIMP was lower (0.35 in HIMP for both sides, 0.32 in SHIMP rightwards, and 0.33 in SHIMP leftwards). In 90% of the patients there was agreement between SHIMP and HIMP on the diagnoses of BV (VOR gain <0.6 or not).

Conclusion. To our knowledge, this is the largest study population on SHIMP testing in BV patients. Covert saccades and VOR gains were significantly reduced during SHIMP, compared to HIMP. However, the clinical relevance of these statistically significant differences is small. Based on this large study population, current HIMP and SHIMP paradigm are both able to diagnose BV. To conclude, the current HIMP paradigm seems to be sufficient to identify BV, despite of the interference of covert saccades.

FP09083 Tesla MRI of Vestibular Endolymphatic Space in patients with isolated Cystic Lateral Semicircular Canal Malformation

Víctor Manuel Suárez-Vega, Pablo Domínguez, Nicolás Perez-Fernandez

Clínica Universidad de Navarra

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Research background: Congenital malformations of the inner ear are characterized by small structural changes and variations in the anatomical development. Among them, one of the most frequent malformation of the bony labyrinth is the one affecting the lateral semicircular canal (LSCC). Isolated LSCC dysplasia (LSCCD) shows no cochlear associated abnormalities and no dilated vestibular aqueduct. The aim of this study is to depict morphology and size of the endolymphatic space in the vestibules of patients with isolated LSCCD using a dedicated 3D high resolution MR sequence called 3D inversion recovery with REAL reconstruction (3D-REAL-IR).

Methods: From January 2018 to February 2020, we reviewed 281 CT and 241 MR temporal bone studies as well as 103 MR studies performed for the evaluation of endolymphatic hydrops (EH). Five patients with LSCCD were found, one of them with bilateral malformation. Three patients (4 affected ears) underwent specific MR examination for the evaluation of EH, consisting on a heavily T2-weighed cysternography sequence (T2 SPACE) and a 3D inversion-recovery with REAL reconstruction. The endolymphatic volumetric ratio (ELR) was calculated as the total endolymphatic volume divided by the total perilymph volume multiplied by 100. Manually delineation of structures by an experienced radiologist and semi-automated generated volumes by the software were obtained.

Results: Hydrops MR imaging was available in 4 of the affected ears. According to the endolymphatic ratio, the most severe ear had a clinical diagnosis of Meniere’s disease and the endolymphatic space encompassed the 81% of the total vestibular lymphatic space, whereas the contralateral “asymptomatic” ear showed a physiological ER of 16%. A patient affected with hearing loss had an ER of 33% and the last affected ear was found incidentally in a patient who was scanned for migraine, with a surprising ER of 42%.

Conclusions: Endolymphatic hydrops imaging is feasible and can be performed on patients with inner ear malformations like the LSCCD. The endolymphatic volumetric ratio could be a useful and easily applicable tool in daily clinical practice. The Target audience Othologist with special interest in vestibular pathologies and Meniere’s disease, as well as Head and Neck Radiologists.

FP0913Bilateral Vestibulopathy Patients’ Perspectives on Vestibular Implant Treatment: A Qualitative Study

Lisa van Stiphout¹, Florence Lucieer¹, Nils Guinand², Angélica Perez Fornos², Maurice van de Berg¹, Vincent van Rompaey³, Josine Widdershoven^1,3, Herman Kingma^1,4, Manuela Joore^5,6, Raymond van de Berg^1,4

¹Department of Otorhinolaryngology and Head and Neck Surgery, Division of Balance Disorders, Maastricht University Medical Center, School for Mental Health and Neuroscience, Maastricht, Netherlands; ²Service of Otorhinolaryngology Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland; ³Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; ⁴Faculty of Physics, Tomsk State Research University, Tomsk, Russian Federation; ⁵Department of Clinical Epidemiology and Medical Technology Assessment (KEMTA), Maastricht University Medical; ⁶Care and Public Health Research Institute (CAPHRI), Maastricht University, Maastricht, The Netherlands

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Objectives: The aim of this study was to explore expectations of patients with bilateral vestibulopathy regarding vestibular implant treatment. This could advance the definition of recommendations for future core outcome sets of vestibular implantation and help to determine on which characteristics of bilateral vestibulopathy future vestibular implant research should focus.

Methods: Semi-structured interviews were conducted with 50 patients diagnosed with bilateral vestibulopathy at Maastricht UMC+. Interviews followed a semi-structured interview guide and were recorded and transcribed. Transcripts were analysed thematically by two independent researchers. A consensus meeting took place to produce a joint interpretation for greater dimensionality and to confirm key themes.

Results: Overall, patient expectations centralized around three key themes: (physical) symptom reduction, functions and activities, and quality of life. These themes appeared to be interrelated. Patient expectations focused on the activity walking (in a straight line), reducing the symptom oscillopsia and being able to live the life they had before bilateral vestibulopathy developed. In general, patients indicated to be satisfied with small improvements.

Conclusion: This study demonstrated that patient expectations regarding a vestibular implant focus on three key themes: symptom reduction, functions and activities, and quality of life. These themes closely match the functional improvements shown in recent vestibular implantation research. The results of this study provide a clear guideline from the patient perspective on which characteristics of bilateral vestibulopathy, future vestibular implant research should focus.

FP0914Development and content validity of the Bilateral Vestibulopathy Questionnaire

Lisa van Stiphout¹, Israt Hossein¹, Merel Kimman², Susan Withney³, Andrianna Ayiotis⁴, Michael Strupp⁵, Nils Guinand⁶, Angélica Pérez Fornos⁶, Angel Ramos⁷, Vincent Van Rompaey⁸, Raymond van de Berg¹

¹Department of Otorhinolaryngology and Head and Neck Surgery, Division of Balance Disorders, Maastricht University Medical Center, School for Mental Health and Neuroscience, Maastricht, Netherlands; ²Department of Clinical Epidemiology and Medical Technology Assessment (KEMTA), Maastricht University Medical center, Maastricht, Netherlands; ³Department of Physical Therapy, School of Health and Rehabilitation Sciences, Duquesne University, Pittsburgh, Pennsylvania, U.S.A; ⁴The Departments of Otolaryngology–Head and Neck Surgery and Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, U.S.A.; ⁵The Department of Neurology, University of Munich, Munich, Germany; ⁶Service of Otorhinolaryngology Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland; ⁷Department of Otolaryngology, Head and Neck Surgery, Complejo Hospitalario Universitario Insular Materno Infantil de Gran Canaria, Las Palmas, Spain; ⁸Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium

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Background: To date, the burden and severity of the full spectrum of bilateral vestibulopathy (BV) symptoms is not measured in a standardized manner. Since therapeutic interventions focusing on improving BV symptoms are emerging (e.g. the vestibular implant, balance belt and noisy galvanic stimulation), the need for a new standardized assessment tool that embraces all aspects of BV arises. Therefore, the aim of this study was to develop a multi-item Patient Reported Outcome Measure, that captures all clinically important symptoms of BV and assesses its impact on daily life.

Methods: The development of the Bilateral Vestibulopathy Questionnaire (BVQ) consisted of two phases: (I) initial item generation and (II) face and content validity testing using cognitive interviews to gain insight in patients’ perspectives and an international expert meeting to obtain input from BV experts. Items were derived from a previous literature review and individual semi-structured interviews focusing on the full spectrum of reported BV symptoms (I). Subsequently (IIa), individual patient interviews were conducted using thinking aloud and concurrent verbal probing techniques to assess the comprehensibility of the instructions, questions and response options, and the relevance, missing domains or missing items. Finally, international experts with extensive experience in the field of the physical, emotional and cognitive symptoms of BV were invited to participate in an online focus group to assess the relevance and comprehensiveness of the BVQ (IIb).

Results: The BVQ that was developed consisted of two sections. The first section included seven constructs with a total of 50 items scored on a six-point Likert scale: three constructs regarding physical symptoms (imbalance, oscillopsia and other physical symptoms), one construct encompassing cognitive symptoms, one construct encompassing emotional symptoms, one construct comprising limitations and behavioral changes and one construct regarding social life. The second part consisted of four items, each scored on a visual analog scale from zero to 100, to inquire about limitations in daily life, perceived health and expectations regarding future recovery. Interviews with BV patients (n=8, 50% female, mean age 56 years (range 24-88 years)) and the expert meeting confirmed face and content validity of the developed BVQ.

Conclusion: The BVQ, which was developed to assess the full spectrum of BV symptoms and its impact on daily life, proved to have good face and content validity. It can be used to characterize the current self-reported symptoms and disability and to depict symptom burden before and after therapeutic interventions such as vestibular implant therapy.

FP0916Case report: Paroxysmal positional vertigo - not always benign

Maritta Spiegelberg, Alexander Tarnutzer

Neurology Department, Cantonal Hospital Baden, Switzerland

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Introduction: BPPV is the most common cause of positional vertigo. However, in a small fraction of cases, central and potentially life-threatening underlying diseases may mimic the clinical presentation of BPPV. Thus persistent paroxysmal positional nystagmus not responding to repositioning maneuvers for BPPV should result in a careful search for additional neurological symptoms and investigations.

Objective: The case report presented here should promote awareness that persistent positional vertigo and nystagmus not responding to repositioning maneuvers and / or with associated neurological symptoms require further diagnostic testing including neuro-imaging in every doubtful case to rule out intracranial pathologies.

Case report: A 45-year old man complained about a sudden onset of episodic positional spinning vertigo with nausea / vomiting when lying down on the left and right side since two weeks and a gait disorder. Right supine roll 90° maneuver revealed a discreet horizontal apogeotropic persistent nystagmus and vertigo, left supine roll maneuver provoked a moderate horizontal apogeotropic nystagmus and severe vertigo. After otokonia mobilisation by vibration, a 360°-barbecue repositioning maneuver was performed leading to an improvement of symptoms. A diagnosis of cupulolithiasis of the right horizontal semicircular canal was made. During the control the next day, however, the patient again presented with a horizontal apogeotropic persistent nystagmus and vertigo. Hence a brain-MRI scan was scheduled due to newly arising complaints of pharmacoresistent nausea and vomiting and worsening gait disorder. The brain MRI scan revealed multiple intracranial, mainly cystic lesions with compression of the fourth ventricle, the brainstem and the left cerebellar hemisphere. Neurosurgical resection of the cerebellar mass revealed a diagnosis of cerebral metastases of an until then undiagnosed adenocarcinoma of the lung.

Conclusion: Central causes must be suspected when progressive, therapy-resistant paroxysmal positional nystagmus and vertigo in combination with other neurological deficits occur or if nystagmus pattern are atypical during provocation maneuvers. In 12 – 20 % of cases an underlying central pathology is identified, including cerebellar tumors, internal auditory canal masses, cerebello-pontine angle tumors, obstructive hydrocephalus, lipoma, glioma and meningioma. Furthermore BPPV and additional intracranial tumors may coexist.

FP0917Functional head impulse test in PPPD subjects without and with Optokinetic Stimulation

Cangiano Jacopo, Gatti Omar, Bussi Mario

San Raffaele Scientific Institute

Persistent Postural Perceptual Dizziness (PPPD) is a functional chronic clinical condition characterized by unsteadiness present on most days for a period of at least 3 months. Either a vestibular disorder or a psychological distress may lead to the disorder. Visual stimuli are commonly reported among exacerbating conditions. In our cross sectional prospective study we studied vestibular function in 25 PPPD subjects through a video-HIT, a bedside examination (including skull vibration test, head shaking and positional tests) and a functional-HIT. The latter is based on having the patient identify an optotype displayed on a computer screen for a short time during passive head rotations; results are expressed in percentage of recognized optotypes. The test was repeated while an optokinetic stimulation (OKS) was given on the screen. Results of the functional-HIT without and with OKS have been compared with those of 25 healthy subjects. Moreover, patients were asked to perform a STAI questionnaire and anxiety levels before and after OKS test were assessed with a VAS scale. Video-HIT and f-HIT without OKS showed normal values in all subjects. F-HIT with OKS provoked more reading errors in patients than in controls. The interaction of group per time detected a different trend of decrease between the two groups (p=0.0002). Patients presented increased anxiety levels before testing, which was reduced after the exam. Among PPPD subjects nine fulfilled criteria for definite vestibular migraine and 8 of them presented nystagmus in at least one of the tests during bedside examination. Only anxiety before OKS test was predictive of worsening of f-HIT results (p=0.0007). Different possibilities have been considered to explain results. Increased anxiety levels may play a role in visuo-vestibular interactions; moreover our data are not inconsistent with the possibility that these subjects present a “hypersensitive” visual alarm system, and OKS might provoke a “threatening effect”, leading to a gaze bias during examination

FP0919Primary Large B-cell Lymphoma of the Central Nervous System presenting as a Vestibular Syndrome

Pedro Valente, Cristina Aguiar, Eugénia Castro, Artur Condé, João Larangeiro

Otolaryngology Department of Centro Hospitalar de Vila Nova de Gaia/Espinho

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Background: Dizziness and vertigo are frequent complaints in patients seeking care in emergency departments. Although they are typically considered to have a peripheral cause, the underlying pathology can be serious, and misdiagnosis may have a significant impact on treatment, quality of life and patient outcome. The authors present a case of a patient diagnosed with Primary Diffuse Large B-Cell Lymphoma (DLBCL) of the Central Nervous System (CNS) and review the literature regarding the presentation, diagnosis, treatment and prognosis of this entity.

Case Presentation: A 74-year-old woman presented to the ENT emergency department due to dizziness complaints during the previous two months, associated with intense nausea/vomiting. She described frequent episodes of instability, with non-spinning quality, triggered by head movements, which worsened progressively, leading to significant weight loss and generalized asthenia. The patient denied focal neurologic deficit or other cochleovestibular complaints, fever, chills, or night sweats.

On admission, vital signs were stable. The otoneurological examination showed direction-changing, bilateral horizontal gaze-evoked nystagmus, with an upbeat vertical component during upward-gaze, negative head impulse test and absence of skew deviation. Non-contrast head computed tomography (CT) demonstrated no visible masses or hemorrhage. Brain magnetic resonance imaging (MRI) revealed a homogeneous T2 hyperintense, gadolinium-enhancing lesion involving the fourth ventricle, brainstem, cerebellar peduncles and hemispheres (Figure 1). Cerebrospinal fluid analysis was normal and flow cytometry was negative for malignancy. The patient underwent a posterior fossa craniotomy with stereotactic biopsy of the lesion. Histopathological analysis showed large neoplastic lymphoid cells and immunohistochemical staining was consistent with the diagnosis of DLBCL.

Figure 1:

CNS Primary DLBCL on MRI.

The patient was considered unfit for systemic intensive chemotherapy and started on palliative treatment with dexamethasone and procarbazine. She deceased due to a respiratory infection two months later.

Discussion and Conclusion: Primary DLBCL of the CNS is a rare, malignant non-Hodgkin lymphoma (NHL), estimated to account for less than 1% of all NHLs. Although typically associated with immunocompromised patients; its incidence among the immunocompetent elderly population is increasing.

Tumor location determines the clinical presentation, most frequently with non-specific focal neurological or neuropsychiatric symptoms. Isolated vestibular complaints have been seldomly reported as the initial manifestation. The histopathological examination with adequate immunohistochemistry testing is the diagnostic gold standard. Primary DLBCL of the CNS is an aggressive tumor with high rates of recurrence after treatment. The combination of chemotherapy and radiotherapy is the standard treatment and have consistently improved survival, despite the overall poor prognosis.

FP0920Clinically Isolated Syndrome presenting with Vertigo, Hearing Loss and normal HINTS examination

Pedro Valente, Isabel Pinto, Eugénia Castro, Artur Condé, João Larangeiro

Otolaryngology Department of Centro Hospitalar de Vila Nova de Gaia/Espinho

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Background: Acute vestibular syndrome (AVS) presents as a spontaneous episode of severe vertigo, with sudden onset and prolonged duration. Causes of AVS most often include vestibular neuritis and stroke, although demyelinating diseases may also mimic vestibular neuritis and are estimated to account for 4% of all AVS episodes.

Case Presentation: A 17-year-old female teenager presented to the ENT emergency department due to complaints of spontaneous, persistent vertigo and right-sided hearing loss in the previous seven days, associated with nausea and vomiting. The otoneurological examination showed unidirectional left-beating horizontal-torsional nystagmus, grade 3 (all gaze positions), pathological head impulse test to the right side and absence of skew deviation. Pure-tone audiometry confirmed a right-sided moderate high-frequency sensorineural hearing loss (Figure 1A) and a video head impulse test (vHIT) revealed a slightly reduced vestibulo-ocular reflex (VOR) gain (0.77) in the right horizontal canal (Figure 2A). The patient was admitted due to a presumed acute labyrinthitis and started treatment with corticosteroids and anti-emetic medication. Improvement on dizziness and hearing impairment was remarkable with complete recovery of normal hearing levels within just four days of treatment (Figure 1B) and normalized horizontal canal VOR gain (Figure 2B). A brain magnetic resonance imaging (MRI) was performed, revealing multiple lesions including in the right middle cerebellar peduncle and cerebellar hemisphere white matter, suggestive a demyelinating etiology (Figure 3). The patient was discharged and completed adequate study, which confirmed the diagnosis of Multiple Sclerosis.

Figure 1:

Right-ear pure tone audiograms. A – Initial audiogram; B – Post-treatment audiogram showing complete recovery of normal hearing levels.

Figure 2:

Lateral canal (LC) video head impulse test (vHIT) in both ears at the time of diagnosis. Blue and orange waves represent head velocity, green waves represent inverted eye velocity, and red waves represent saccades. A – Initial vHIT with reduced VOR gain (0.77) in the right LC. B – Follow-up vHIT assessment with normal VOR gain (1.07) in the right LC.

Figure 3:

Brain MRI revealed multiple high-intensity lesions in a typical demyelinating disease topography including the right middle cerebellar peduncle (A) and the cerebellar hemisphere white matter (B).

Discussion and Conclusion: Multiple sclerosis is the most common chronic inflammatory disease of the central nervous system (CNS) and, despite the continuous evolution in our understanding of this pathology, its underlying cause remains elusive and it is currently incurable. Patients with MS commonly report dizziness and vertigo either as an initial manifestation or during the course the disease. On the other hand, hearing impairment, specifically sudden sensorineural hearing loss (SSNHL), is rarely found in an initial presentation of MS. In the reported case, the initial bedside testing was suggestive of a peripheral vestibular cause, according to the HINTS paradigm and vHIT testing. The presence of SSNHL raised the suspicion of CNS disease and prompted imaging evaluation, which allowed the final diagnosis of MS. This case highlights the importance of an accurate diagnosis in patients presenting with an acute vestibular syndrome, keeping in mind the uncommon central causes, namely multiple sclerosis, where the timely initiation of appropriate disease-modifying therapies has been shown to be clinically effective.

FP0923Analysis of heel stepping motion using nine-axis motion sensor.

Toru Miwa

Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University

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A motion sensor is an electronic device that is designed to detect and measure movement. Motion sensors are used primarily in home and business security systems, but they can also be found in phones, paper towel dispensers, game consoles, and virtual reality systems. This technology will be utilized to improve the body balance in the future. We collected heel step test data on the force plate (Foulage test) for 6 healthy adults (all men aged 27.32±5.89) using an accelerometric device, nine-axis motion sensor. The subjects were demonstrated Foulage test with nine-axis motion sensor in their lumbar spine, and data were analyzed and examined correlations. Root mean square (RMS), auto-correlation coefficient (AC) and Euler horn were calculated from nine-axis motion sensor. Moving distance (FT value) and rotation angle (θ value) were calculated from Foulage test. There were significant correlations between AC x-axis of linear/ angular acceleration and FT value. There were also significant correlations between Euler horn y-axis and θ value. Our results suggested x-axis of lumbar spine affected Foulage stepping. This accelerometric device is easy to use and requires no specialized equipment and could be used to analyze Foulage test in clinical practice. We will show the results of relationship between Foulage test and motion sensor of head and neck spine during the conference.

FP0927Does the tuning property shift in cVEMP reflect endolymphatic hydrops revealed by MRI study?

Toshihisa Murofushi, Masahito Tsubota, Koji Nishimura

Teikyo University School of Medicine Mizonokuchi Hospital

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Background: Meniere’s disease (MD) is one of the representative peripheral vestibular diseases, characterized by episodic vertigo attacks accompanied by fluctuated auditory symptoms/signs. As endolymphatic hydrops (EH) is one of the histopathological features of MD, detection of EH using clinical neurophyiological tests such as cervical vestibular evoked myogenic potential (cVEMP), electrocochleography (ECoG) and so on have been performed. Nowadays MRI has been applied for detection of EH. However, correspondence of neurophysiological test results to MRI findings is not fully investigated.

Objective: In this study we tried to examine correspondence of cVEMP tuning property test results to MRI findings.

Subjects and Methods: Patients diagnosed with having MD or MD related vestibular diseases were enrolled. These patients underwent cVEMP tuning property test and MRI for assessment of EH. For cVEMP tuning property test, cVEMPs were measured using 500Hz and 1000Hz short tone bursts (STB)(air-conducted, 125dBSPL). As an index of EH, 500-1000 Hz cVEMP slope (=SLOPE) was calculated. Here, SLOPE = 100x(A500-A1000)/(A500+A1000). A500: normalized amplitude of p13-n23 to 500Hz STB, A1000: normalized amplitude of p13-n23 to 1000Hz STB. According to the previous studies, SLOPE< -19.9 was regarded as EH positive. Inner ear scans using 3T-MRI was taken 4 hours after gadolinium intravenous injection. For assessment of EH in MRI, we used grading by Nakashima T et al. (Acta Otolaryngol 2009;129:5-8) and regarded “Significant” in this grading as EH positive.

Results: Statistically significant association was shown between cVEMP slope findings and MRI findings (chi-square test, p<0.01).

Conclusion: EH positive and EH negative in cVEMP tuning property test correspond to MRI findings of EH.

FP0928PPPD patients show lack of habituation to repetitive stimuli? Study in auditory middle latency response (AMLR)

Toshihisa Murofushi, Fumiyuki Goto

Teikyo University School of Medicine Mizonokuchi Hospital

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Background: We have reported that vestibular miraine (VM) patients show lack of habituation to repetitive stimuli in auditory middle latency responses (AMLR). This phenomenon is considered to be caused by sensory processing disorders in the central nervous system. Habituation diorders in other chronic vestibular disease remain unclear.

Objective: To clarify whether PPPD (persistent perceptual postural dizziness) patients show lack of habituation to repetitives stimuli using auditory middle latency response (AMLR).

Subjects and Methods: Patients diagnosed with having PPPD were enrolled. Also, patients with vestibular migraine (VM), Meniere’s disease (MD) and healthy subjects (HC) were enrolled for comparison. These subjects underwent AMLR tests. The electrodes were placed on the vertex and the spinal process of the fifth cervical vertebra. Binaural click stimulation (0.1 msec, 70dBnHL) was presented. Totally 800 responses were averaged. Averaged responses were divided into 4 sets (S1 to S4) according to the temporal order. No, Po, Na, and Pa were identified, and amplitudes and latencies were measured. Because Na-Pa amplitudes showed significant difference amogb VM, MD, and HC in the previous study (Murofushi T et al. 2020), we mainly studied Na-Pa amplitude.

Results: While relative amplitude of Na-Pa in S4 to S1 showed decreasing in MD patients and HC (habituation), VM patients and PPPD patients showed lack of habituation. Although difference between VM patients and PPPD patients was not significant, VM patients showed tendency of clearer potentiaton than PPPD patients.

Conclusion: Habituation disorders to repetitive sensory stimuli might be a part of sensory processing disorders in PPPD patients, leading to prolongation of their symptoms.

FP0929Acute Unilateral Vestibular Hypofunction, Is It Vestibular Neuronitis... Or not?

R Andrés Navarro-Mediano, Estefanía Hernández-García, Mar Martínez and Guillermo Plaza

Hospital Universitario de Fuenlabrada

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Vertigo in an emergency room context is challenging and may involve different pathologies which converge in the same symptoms. This poster shows the case of a 58 years old woman who came to our hospital referring 1 week of continuous vertigo, inestability and nausea. She had no other symptoms. She presented a grade 1 left nystagmus and the v-HIT showed unilateral right hypofunction and overt and covert saccades. She was diagnosed of right vestibular neuronitis and started ambulatory treatment. She returned after 10 days with the same symptoms and underwent a CT brain scan that was informed as not presenting relevant findings. Three weeks later she returned with persistent vertigo and inestability and right facial palsy with peripheral characteristics. She underwent another CT scan which then showed right temporal subcortical hypodensity, and a MRI thereafter revealed multiple bilateral T2-hyperintense periventricular and deep supratentorial lesions at the union between the medium right cerebellar peduncule and the posterior bulbopontine region suggesting demyelinating disease or subacute encefalitis. She was treated with antivirals, ampicillin and steroids, and the serologies and the cerebrospinal fluid findings were negative which left the diagnose to demyelinating disease. After a month she was revaluated and she had no longer vertigo or facial palsy but she kept complaining of instability. Then, v-HIT improved showing bilateral normofunction with no saccades. She is still being studied by neurology up to date with no definite diagnose. This clinical case shows that acute vestibular syndromes, even when having compatible exploration and v-HIT can surprise us and we must stay alert of other possibilities.

FP0935Vestibular compensation and perceived disability in a population of vestibular neuritis

Jonathan Esteban-Sanchez¹, Almudena Rueda-Marcos², Eduardo Martin-Sanz¹

¹Otoneurology Unit. University Hospital of Getafe; ²Neurology Unit. University Hospital of Getafe

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Introduction: Vestibular neuritis (VN) is the most common cause of acute spontaneous vertigo.

An individual’s progress or lack of progress in vestibular restoration is usually measured by observing changes in vhit gain values, some patterns of saccades, motion intolerance, balance, functional abilities and more recently, health-related quality of life

Objetives: In this study we used CDP, SF36, AVS, DHI to evaluate the unsteadiness and quality of life status in patients with VN. To evaluate vestibular impairment and recovery/compensation mechanisms.

Material and Methods: A prospective, longitudinal study was conduced in the ENT Department between January 2018 and December 2019. There was 38 consecutive patients diagnosed with vestibular neuritis. All patients were monitored for 12 months

All patients underwent a complete physical examination and currently available conventional diagnostic test (bed-side vestibular examination, videonystagmography, VHIT, caloric test, cervical and ocular VEMP and computerized dynamic posturography (CDP).

All patients were submitted to customize a SF36 health survey questionnaire, an AVS and the DHI for assessing the disability.

Results: Demographic and clinical data were comparable between men and women.

Successive vHIT results showed a significantly vestibulo-ocular reflex gain recovery in vestibular neuritis patients. There is a reduction in percentaje of saccades with decrease in the latency, velocity, and organization of the compensatory saccades was observed.

This study shows statistically significant association between the VHIT test and SOT and limits of stability results of CDP.

There was a statistical significant difference for each parameter of DHI score (the emotional, functional and physical) between all visits. There is also statistical significant difference for almost all dimensions evaluated by SF-36 test between all visits. AVS showed similar results with great correlation with gain values of vHIT.

Conclusions: Vestibular neuritis is caused by an unilateral vestibular function, which is restored over time.

In addition to the recovery of the vestibulo-ocular reflex, the reduction of latency, velocity and the organization of compensatory saccades play a role in vestibular compensation.

Questionnaires such as DHI, SF-36 or AVS are useful tools to quantify the disability perceived by the patients. These questionnaires improve their values with great correlation with vHIT and CDP.

FP0938Postural instability in Parkinson disease and the association with the vestibulospinal tracts involvement

Luciana Cristina Matos Cunha, Sarah Teixeira Camargos, Anna Paula Batista de Ávila Pires, Denise Utsch Gonçalves

Universidade Federal de Minas Gerais

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Introduction: postural instability in Parkinson’s disease (PD) is common, has an unknown pathophysiology and has been associated to cognitive impairment. Galvanic vestibular stimulation (GVS) applied to the mastoid bone triggers a motor response in the posture-controlling muscles. The consequent electromyographic response, which is the vestibular-evoked myogenic potential (VEMP), provides information about the central pathways of the vestibular system, including brainstem, reticulospinal tract and vestibulospinal tracts extending from the cervical to the lumbar spine. Objective: To evaluate the vestibulospinal reflex in PD and to correlate it with cognitive impairment. Methodology: In a transversal design, 60 individuals with PD, of whom 30 presented postural instability (mean age 63 + 54-70 years, 11 women) and 30 did not (56 + 50-63 years, 15 women) as well as 32 healthy controls (58 + 51-68 years, 21 women) were submitted to galvanic stimulation to evoke VEMP and the response was recorded from the soleus muscle (sVEMP). The GVS was characterized as a direct, monophasic, and rectangular current with an intensity of 2 mA and a duration of 400 ms applied as a transmastoid binaural stimulation. The postural instability was defined by a score equal to or greater than 1 in the pull test at the Unified Parkinson Disease Rating Scale (UPDRS) and the Berg Balance Scale (BBS). The cognitive evaluation consisted of a mini examination of the mental state, a clock drawing test, a figures memory test and verbal fluency. Cognitive variables were reduced by means of factorial analysis to only one component called global cognition. The sVEMP variables were the latency and the morphology of the waves. They were correlated with the global cognition, BBS, UPDRS II (functional evaluation) and UPDRS III (motor evaluation). Results: PD with postural instability presented the worst results in UPDRS III (p<0.001), BBS (p<0.001) and global cognition (p=0.005), as expected. The sVEMP variables were not different in the groups with and without instability (p>0.005), but these groups presented worse sVEMP latencies comparing to the controls. Global cognition was not correlated with alteration in sVEMP. Conclusion: The vestibulospinal reflex was found to be altered in the early stages of PD, which supports the theory that the vestibular system plays a role in, but not truly explain, the postural instability in PD. The association of bad cognition and postural instability seems to be multifactorial, since an alteration in the vestibulospinal reflex was found before any clinical symptom of cognitive alteration.

FP0940Vibration-Induced-Nystagmus Contribution to the Unilateral Superior Semicircular Canal Dehiscence Syndrome vs Otosclerosis Diagnosis

Armin De Luca; Vanesa Pérez Guillén; Lidia Torres García; Ana Belén Castilla Jiménez; Herminio Pérez Garrigues

Hospital Universitari y Politècnic La Fe

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Introduction: The Superior Semicircular Canal Dehiscence Syndrome (SSCDS) is an infrequent entity that can present itself with vestibular symptoms associated with loud noises or increases in the intracranial pressure, as well as, conductive hearing loss, aural fullness and tinnitus. It’s not uncommon for this syndrome to present itself only with audiological symptoms mimicking Otosclerosis (OS).

Even though the definitive diagnosis for both entities relies strongly on temporal bone computerized tomography (CT), the vibration-induced-nystagmus (VIN) test may be a useful initial in-office evaluation to discriminate SSCDS from OS.

Methods and Material:

Studied population:

- 6 patients with confirmed SSCDS using temporal bone CT in whom tonal audiometry, tympanometry, stapedial reflex, video head impulse test (vHIT) and VIN test were performed.

- 11 patients with confirmed OS using temporal bone CT in whom the same complementary tests as in the SSCDS group were performed.

The VIN test was performed by using a 100Hz stimulus on both mastoids and the ophryon (anterior central cranial point) using a Sinapsis VVIV stimulator.

Results: Four of the patients with SSCDS presented a unilateral low frequency conductive hearing loss and all of them had a normal tympanometry and stapedial reflex. The vHIT was also normal in the six patients. The temporal CT showed a SSCD in every patient (2 of them bilateral). Every patient that had a unilateral finding (radiologic and audiometric) had a positive VIN test while stimulating with 100HZ (x=9.76 DS 3,24 °/second) at the ophryon. The direction of the fast phase of said nystagmus, while stimulating a central cranial point, beat to the same side of the dehiscence. Patients with bilateral findings had a negative VIN test. Each one of the patients with OS had a conductive hearing loss associated with a negative stapedial reflex and radiologic findings suggestive of otospongiosis. The VIN test was also negative in the 11 patients.

Conclusion: The VIN test is an un-expensive, simple and well-tolerated tool that may be useful as a guide in those patients in which the clinical presentation is unspecific and suggestive of either SSCDS or OS. Nevertheless, a negative finding in a patient with bilateral SSCDS compels to continue to perform other complementary tests to better discriminate the diagnosis.

FP0942Parameters of Off-Vertical Axis Rotation in Unilateral andBilateral Vestibulopathy and Their Correlation with VestibularEvoked Myogenic Potentials

Goun Choe¹, Shin Hye Kim², Sang-Yeon Lee³, Ji-Soo Kim⁴ and Ja-Won Koo¹

¹Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam 13620, Korea; ²Uijeongbu Eulji Medical Center, Department of Otorhinolaryngology-Head and Neck Surgery, Eulji University College of Medicine, Uijeongbu 11759, Korea; ³Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea; ⁴ Department of Neurology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam 13620, Korea

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Off-vertical axis rotation (OVAR) is a laboratory test to assess the otolith function. This study aimed to analyze the parameters of OVAR in patients with unilateral vestibular hypofunction (UVH) and bilateral vestibulopathy (BVP), and to correlate the parameters of OVAR with those of VEMPs. Ten healthy volunteers, 41 UVH, and 13 BVP patients performed OVAR. Bias component (BIC) and modulation component (MOC) of UVH and BVP patients were compared with those of healthy controls. BIC and MOC were correlated with amplitude and interaural difference (IAD) of cervical VEMP (cVEMP) and ocular VEMP (oVEMP). In UVH patients, the direction of BICs to affected side rotation were reversed and the absolute value of BICs were decreased when they were compared to healthy controls. In BVP patients, BICs were markedly attenuated. MOCs were not changed in UVH and BVP patients. There was no statistically significant correlation between VEMPs and OVAR.

FP0944VEMPlitude: Is It Worth It?

Harry Akram, Laura Freeman

University College London Hospitals

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I describe and discuss results of a study on Ocular VEMP amplitudes, comparing conventional montage to a variation of the “Belly-Tendon” montage (as described by Sandhu, 2013 and Colebatch, 2013) showing, on average, amplitudes are twice as large with the “BT” method and at worst, exactly the same. Previous studies describe the risk of ocular mygonenic interference from non-test sites but we demonstrate that it is a very low risk. We discuss the advantages and disadvantages and also my motivations for exploring this in relation to public health and vestibular assessments. This will be of interest to diagnosticians, particularly Audiologists, Audiological Scientists and anyone conducting oVEMP on their clinic. Finally, I propose that my new montage is named after popular Rythm and Blues vocalist Missy Elliot.

FP0949Effect of Electric Vestibular Stimulation on Oculomotor Control During Head Movements in Healthy and Vestibular Lesions

Maja Striteska^1,2, Jan Kremlacek³

¹Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital Hradec Kralove, Charles University, Faculty of Medicine in Hradec Kralove, Czech Republic; ²Department of Otorhinolaryngology, Charles University in Prague, 3rd Faculty of Medicine, University Hospital Kralovske Vinohrady, Czech Republic; ³Department of Medical Biophysics and Department of Pathological Physiology, Charles University, Faculty of Medicine in Hradec Kralove, Czech Republic

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Study preliminary data:

Introduction: Transcranial electric vestibular stimulation (tEVS) plays an essential role in the quest to understand sensory signal processing in the vestibular (balance) system and in investigating future treatment options for patients with different vestibular lesions. The study arises from a need to understand the tEVS interaction with a concurrent vestibular signal from an intact side during natural head movements.

Methods: Different tEVS attributes such as the type of current modulation (waveform, pulses, etc.), timing of pulses, signal intensity (0.3 to 0.5 mA), etc., were explored during motionless condition and during active or passive head movements (rotations), using the current and shame signals in healthy volunteers first. The head movements were explored in the frequency range from 1 Hz (VOG) to approximately 5 Hz (VHIT). During the second phase patients with different one sided peripheral vestibular lesions will be enrolled and divided in subgroups according to their diagnosis. The same protocol from the first phase will be used. Statistical data will be evaluated.

Preliminary data: The VOG traces showed well detectable vestibular responses to tDCS. Opposite, the VHIT gains were not affected neither from any stimulation in healthy. We hypothesize, the current provides such a small vestibular excitation (in spontaneous nystagmus only 1-2 aSPV response, emphasized by a head shake to 3-4 aSPV), that this small change in a function is well-tolerated or hidden as a small error during such a strong vestibular impulse, as high head acceleration during a head impulse test. This could affect some other hypotheses. Especially, why in some vestibular disorders like vestibular schwannoma or Meniere’s disease, low frequencies (of head movement) of tested vestibuloocular reflex (as spontaneous nystagmus and head shake are), are affected first, while high frequencies are affected later. Maybe due to a tolerance of a signal error. Next hypothesis could be based on a different vestibular hair cells type I and II sensitivity to electrical stimulation, while type I hair cells are associated with large vestibular afferents with an irregular neural firing pattern, while type II are associated with small vestibular afferents that display a regular neural firing pattern (Baloh a Honrubia 2001), dimorphic units could be either regular or irregular units. Irregular nerve fibres are larger and have higher conduction velocities (Goldberg, Fernandez, 1977[1]), are more efficient at transmitting excitatory information and are more sensitive to transient motion (Fernandéz, Goldberg, 1976, Goldberg 2000 [2, 3]).

FP0950Head-shaking Test discriminates Growth and Stable Vestibular Schwannoma

Maja Striteska^1,2, Martin Valis³, Martin Chovanec², Oliver Profant^2,4, Jan Kremlacek⁵

¹Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital Hradec Kralove, Charles University, Faculty of Medicine in Hradec Kralove, Czech Republic; ²Department of Otorhinolaryngology, Charles University in Prague, ³rd Faculty of Medicine, University Hospital Kralovske Vinohrady, Czech Republic; ³Department of Neurology, University Hospital Hradec Kralove, Charles University, Faculty of Medicine in Hradec Kralove, Czech Republic; ⁴Department of Auditory Neuroscience, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czech Republic; ⁵Biophysics and Department of Pathological Physiology, Charles University, Faculty of Medicine in Hradec Kralove, Czech Republic

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Abstract

Objective: To assess the potential of the head-shaking test to discriminate between the stable and growing vestibular schwannoma.

Study Design: Prospective study, schwannoma patients and healthy controls were enrolled.

Setting: Outpatients of a tertiary referral center.

Methods: One-hundred twenty-eight subjects were enrolled in a study from September 2016 to August 2021. Two vestibular schwannoma groups (stable and growing group) and one control group of healthy volunteers were examined with a Videooculography test battery and Video Head Impulse Test.

Results: We analysed the potential of each test to discriminate between growing and stable vestibular schwannomas. The ROC analysis of spontaneous nystagmus showed 48% specificity and 96% sensitivity for the average slow phase velocity cut-off (aSPV) 0.5 o/s. The caloric test cut-off 41% unilateral weakness had 59% specificity and 100% sensitivity, video head impulse test gain cut-off 0.8 had 56% specificity and 96% sensitivity, head-shaking induced nystagmus cut-off 0. 5 o/s aSPV showed 96% specificity and 89% sensitivity.

Conclusions: Our study showed the potential of the head-shaking test to identify a growth activity of vestibular schwannoma.

FP0951Estimated Vestibulogram (EVEST) for Effective Vestibular Assessment

Maja Striteska^1,2, Lukas Skoloudik¹, Martin Valis³, Jan Mejzlik¹, Katerina Trnkova², Martin Chovanec², Oliver Profant^2,4, Viktor Chrobok¹, Jan Kremlacek⁵

¹Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital Hradec Kralove, Charles University, Faculty of Medicine in Hradec Kralove, Czech Republic; ²Department of Otorhinolaryngology, Charles University in Prague, ³rd Faculty of Medicine, University Hospital Kralovske Vinohrady, Czech Republic; ³Department of Neurology, University Hospital Hradec Kralove, Charles University, Faculty of Medicine in Hradec Kralove, Czech Republic; ⁴Department of Auditory Neuroscience, Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, Czech Republic; ⁵Department of Biophysics and Department of Pathological Physiology, Charles University, Faculty of Medicine in Hradec Kralove, Czech Republic

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Abstract

Background. The availability and development of methods testing the vestibuloocular reflex (VOR) brought a broader view into the lateral semicircular canal (L-SCC) function. However, the higher number of evaluated parameters makes more difficult the specialist’s diagnose-making process. Purpose. To provide medical specialists, a new diagnostic-graphic tool, Estimated Vestibulogram- EVEST, enabling a quick and easy-to-read visualization and comparison of the VOR test results within the L-SCC. Methods. The development of EVEST involved 148 participants, including 49 healthy volunteers (28 female and 21 male) and 99 (58 female and 41 male) patients affected by different degrees of peripheral vestibular deficit. The corresponding L-SCC VOR test results, from patients meeting the diagnostic criteria, were used to create the EVEST. Results. Based on the test results, we depicted and calculated the EVEST vestibular function asymmetry (VFA) in all the groups. To assess a feasibility of EVEST to describe a vestibular function deficit, we calculated sensitivity and specificity of VFA using a receiver operating characteristic curve (ROC) and compared it to single tests. In all the tests, we determined the cutoff value as the point with the highest sensitivity and specificity. For discrimination of any vestibular deficit, the VFA with cutoff 6.5% was more sensitive (91%) and specific (98%) than single tests. Results showed that EVEST is a beneficial graphic tool for quick multifrequency comparison and diagnosis of different types of the peripheral vestibular loss. Conclusions. EVEST can help to easily evaluate various types of peripheral vestibular lesion.

FP0954Impairment of the high-frequency vestibulo-ocular reflex for dehiscent semicircular canals: incomplete natural plugging or mechanical energy dissipation?

Andrea Castellucci^1,2, Enrico Armato³, Cristina Brandolini², Pasquale Malara⁴, Salvatore Martellucci⁵, Valeria Del Vecchio^2,6, Angelo Ghidini¹

¹ENT Unit, Arcispedale Santa Maria Nuova, AUSL - IRCCS, Reggio Emilia, Italy; ²ENT and Audiology Unit, S.Orsola-Malpighi University Hospital, Bologna, Italy; ³ENT Unit, SS Giovanni e Paolo Hospital, ULSS Serenissima, Venice, Italy; ⁴Audiology & Vestibology Service, Centromedico, Bellinzona, Switzerland; ⁵ENT Unit, Santa Maria Goretti Hospital, AUSL Latina, Italy; ⁶UOC Audiology & Vestibology Unit, University Hospital Federico II, Naples, Italy.

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It is well known how superior canal dehiscence (SCD) results in audio-vestibular symptoms with low-frequency air-bone gap (ABG) and reduced thresholds for cervical- and ocular-VEMPs for air-conducted (AC) stimuli. Authors have demonstrated on animal models and humans how these data derive from the so-called “third-window effect”, where reduced impedance in the vestibular compartment results in dissipation of acoustic energy and enhanced otolith response to sounds. According to correlation studies, these phenomena seem to occur the wider is the dehiscence. Similarly, most subjects with wide-sized SCD present with impaired vestibulo-ocular reflex (VOR) on video-HIT for the affected superior canal (SC). It has been assumed that this finding might be due to a natural auto-plugging process exerted by middle fossa dura prolapsing through the dehiscence, as it overlaps postoperative VOR-gain measurements in surgically plugged patients who benefit from surgery. Accordingly, patients with wide-sized SCD presenting with SC-VOR hypofunction would be therefore expected to develop poor symptoms. Nevertheless, it is true only for few of them, whereas most patients continue to be symptomatic despite functional SC impairment. We hypothesize that, whereas wide-sized SCD may allow an incomplete canal plugging in some conditions, in most patients membranous SC continues to be patent allowing a dissipation of mechanical energy through the dehiscence. The aim of this paper is to provide further evidences for these assumptions. We compared instrumental data of 36 ears of 35 patients (17 males, 18 females, mean age 56.1 ± 13.6 years old) with SCD presenting with SC VOR-gain impairment (< 0.7) with post-operative data of 10 ears of 10 patients (mean age 51.4 ± 15.7 years old) with SCD who developed SC VOR-gain deficit after surgical canal plugging. All patients underwent audiometry, cervical- and ocular-VEMPs for AC/BC stimuli and video-HIT. Whereas no significant difference was found between the two groups in terms of mean VOR-gain for the affected SC (p > 0.05), mean ABG was significantly smaller (p < 0.01), both cervical- and ocular-VEMPs thresholds for AC stimuli were significantly higher and amplitudes significantly smaller (p < 0.01) in post-operative ears compared with non-surgical patients. In our opinion, these data suggest that the affected canal is patent in the majority of SCD-patients presenting with impaired SC VOR-gain and dissipation of mechanical energy through the dehiscence is more likely to occur than a spontaneous auto-plugging process, where ABG closure and VEMPs data normalization would be rather expected.

FP0955Feasibility of using Video Head Impulse Test to detect the involved canal in Benign Paroxysmal Positional Vertigo presenting with Positional Downbeat Nystagmus

Andrea Castellucci¹, Pasquale Malara², Salvatore Martellucci³, Enrico Armato⁴, Giacinto Asprella Libonati⁵

¹ENT Unit, Arcispedale Santa Maria Nuova, AUSL - IRCCS, Reggio Emilia, Italy; ²Audiology & Vestibology Service, Centromedico, Bellinzona, Switzerland; ³ENT Unit, Santa Maria Goretti Hospital, AUSL Latina, Italy; ⁴ENT Unit, SS Giovanni e Paolo Hospital, ULSS Serenissima, Venice, Italy; ⁵Vestibology and ENT Unit, Giovanni Paolo II Hospital, Policoro, Matera, Italy.

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Positional-downbeat nystagmus (pDBN) represents a relatively frequent finding in clinical practice. Though classically considered a sign of central disorders, thanks to recent advances in vestibular diagnostics and imaging, its primarily peripheral origin could have been ascertained. Nevertheless, distinguishing features of peripheral positional nystagmus, including latency, paroxysm and torsional components, may be missing, resulting in challenging differential diagnosis with central pDBN. Moreover, in case of benign paroxysmal positional vertigo (BPPV), detecting the affected canal may be challenging as the involvement of the non-ampullary arm of posterior canal (PC) results in the same oculomotor responses generated by contralateral anterior canal (AC)-canalolithiasis. Recent acquisitions suggest that patients with persistent pDBN due to vertical canal-BPPV may exhibit impaired vestibulo-ocular reflex (VOR) for the involved canal on video-head impulse test (vHIT). Since canal hypofunction normalizes following proper canalith repositioning procedures (CRP), an incomplete (or transient/positional) canalith jam acting as a “low-pass filter” for the affected ampullary receptor has been hypothesized. This study aims to determine the sensitivity of vHIT in detecting canal involvement in patients presenting with pDBN due to vertical canal-BPPV. We retrospectively reviewed the clinical records of 59 consecutive subjects presenting with peripheral pDBN. All patients were tested with video-Frenzel examination and vHIT at presentation and after resolution of symptoms or transformation in typical BPPV-variant. BPPV involving the non-ampullary tract of PC was diagnosed in 78%, AC-BPPV in 11.9% whereas in 6 cases the involved canal remained unidentified. Presenting VOR-gain values for the affected canal were greatly impaired in cases with persistent pDBN compared to subjects with paroxysmal/transitory nystagmus (p<0.001). VOR-gain values for the affected canal were even more impaired in patients (n.6) presenting with spontaneous DBN (p=0.002), consitent with a complete canalith jam within the PC. Each patient received CRP for BPPV involving the hypoactive canal or, in case of normal VOR-gain, the assumed affected canal. Each subject exhibiting VOR-gain reduction for the involved canal developed normalization of vHIT data after proper repositioning (p<0.001), proving a close relationship with otoliths altering high-frequency cupular responses. According to our results, overall vHIT sensitivity in detecting the affected SC was 72.9%, increasing up to 88.6% when considering only cases with persistent pDBN where an incomplete canal plug is more likely to occur. vHIT should be routinely used in patients with pDBN as it may enable to localize otoconia within the labyrinth, providing further insights to the pathophysiology of peripheral pDBN.

FP0957Overlapping Ménière’s Disease and Vestibular Migraine : Our Experience in Tertiary Referral Institution

Victoria Rivero de Jesús¹, Laura Ruiz Sevilla¹, Francesc Larrosa Diaz¹, Rosana Rodriguez Villalba², Manuel Bernal S¹, Isabel Vilaseca¹

¹Hospital Clínic - Barcelona, Spain; ²Althaia Xarxa Universitaria de Manresa, Spain

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Introduction: Ménière’s Disease (MD) and Vestibular Migraine (VM) are two clinical entities with overlapping signs and symptoms. The differential diagnosis is sometimes hard to perform when MD and VM are simultaneous, the diagnostic is really challenging.

Material and Methods: We analyze a series of 76 patients complying with Bárány’s Society diagnostic criteria for definite MD and/or Definite VM; 10 patients were excluded; we consider 66 patients (24 males, 52 females; age between 31 and 76) attended between 2018 and 2020. We divided them into 3 groups: definite MD group (uni and bilateral), definite VM group and MD + VM group. All patients were submitted to an accurate clinical history, physical examination, tonal audiometry, computerized vestibular testing and the Dizziness Handicap Inventory (DHI).

Results: According to Bárány’s Society diagnostic criteria, we find that 52 patients were definite MD, 11 were definite VM and 13 were overlapping VM / MD. Four patients of the simultaneous VM / MD group presented a positive familiar history for vertigo and/or migraine, 3 suffered a bilateral MD and 10 a unilateral MD .

Conclusion: In our experience, overlapping MD/ VM group is affected by more frequent crisis than definite MD group. DHI demonstrated a worse quality of life in MD + VM group. Females are more represented than males in all 3 groups; 4 patients of the MD/VM group had a positive family history for migraine or definite MD.

In our experience it is difficult to make a diagnostic of overlapping VM/MD. An accurate medical history can lead us to a better diagnostic and treatment.

FP0963Vestibular syncope : Recurrent syncope during the attacks of Meniere’s disease

Eunjin Kwon¹, Ju-Young Lee² Hyo-Jung Kim³, Jeong-Yoon Choi⁴, and Ji-Soo Kim⁴

¹Deparment of Neurology, Chungnam National University Hospital, Daejeon, Korea; ²Department of Neurology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea; ³Department of Neurology, Seoul National University Bundang Hospital, Seongnam, Korea; ⁴Research Administration Team; Seoul National University Bundang Hospital, Seongnam, Korea

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Background & Significance : Vestibulosympathetic reflex is referred to as the relation between the sympathetic nervous system and the vestibular system. We herein the case, who had recurrent syncope that associated with vestibular stimulation. Case : A 79-year-old woman with Meniere’s disease was referred to the clinic to evaluate for recurrent syncope for 12 years. She felt vertigo with tinnitus and hearing difficulty in the left ear. As her symptom got progressed, she had diagnosed with Meniere’s disease 5 years ago. The patient got syncope attack when she felt vertigo, had a loss of consciousness about 2 hours. As she fell, she got a traumatic temporal bone fracture and a small amount of subarachnoid hemorrhage in the bilateral temporal lobes. After the event, she had experienced similar events 4 times within 2 weeks after the discharge. Cardiologic and neurologic syncope evaluation was done and all excluded. In her interictal stage, vestibular function tests were done. As she was diagnosed with Meniere’s disease, the syncope associated with Meniere’s attack was suspected. Thiazide and betahistine for the prevention of syncope were applied and she has gotten free from syncope for 2-year-follow-up. Conclusions : Tumarkin’s otolithic crisis or drop vestibular attack is the main sign of Meniere’s disease, which is syncope with vestibular symptoms. However, the mechanism of the syncope and vestibular dysfunction is not clear yet. There were some studies about sympathetic and cardiovascular activity along with vestibular activity variation both in human and animal. We suggest the mechanism of drop attack as a vestibulosympathetic reflex failure with vestibular pathway impairment.

FP0968The Proteome of the Human Endolymphatic Sac Endolymph

Christine Ölander¹, Jesper Edvardsson Rasmussen¹, Per Olof Eriksson¹, Göran Laurell¹, Helge Rask-Andersen¹, Jonas Bergquist²

¹Department of Surgical Sciences, Otorhinolaryngology and Head and Neck Surgery, Uppsala University, Uppsala, Sweden; ²Department of Chemistry – BMC, Analytical Chemistry, Uppsala University, Uppsala, Sweden

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Advancements in mass spectrometry for the analysis of proteins have greatly improved protein identification. Sampling of endolymph from the endolymphatic sac is difficult because of its small volume and anatomical location, with a high risk of contamination with surrounding tissue fluids and blood. For successful sampling refined techniques are required.

With a tailored solid phase micro-extraction probe we were able to collect five endolymphatic sac endolymph samples and six endolymphatic sac tissue biopsies in patients undergoing trans-labyrinthine surgery for sporadic vestibular schwannoma. After preparation, the samples were analysed with nano-liquid chromatography - tandem mass spectrometry (nLC-MS/MS). The data were analysed with MaxQuant software to identify the total number of proteins. Pathway identification regarding molecular function and protein class was analysed using PANTHER classification system.

In total, 1656 proteins were found. 1211 different proteins were found in the endolymphatic sac endolymph samples and 1546 in the endolymphatic sac tissue biopsies. 1101 of the proteins overlapped, thus the proteins were found in both the endolymph samples and the sac biopsies. 110 of the proteins were unique for the endolymphatic sac endolymph samples as compared to 445 proteins unique for the endolymphatic sac biopsies.

To our knowledge, this mapping of the proteome of the human endolymphatic sac is unique and may form a platform for further investigations to better understand the function of this intriguing tissue in the human inner ear.

FP0970The Suitability of the CAVA Device as an Ambulatory Monitor for Detecting Dizziness

John Phillips¹, Jacob Newman², Stephen Cox²

¹Ear, Nose and Throat Dept., Norfolk and Norwich University Hospital, Norwich, UK; ²School of Computing Sciences, University of East Anglia, Norwich, UK.

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Diagnosis of the dizzy patient is challenging due to its episodic nature, its many possible causes and ambiguity in patient reporting of symptoms. To overcome these limitations, we have developed the CAVA system. The system comprises a medical device that is worn on the face and which continuously records eye and head movement data, and associated computer software for analysing the data collected. The device is intended to be worn by patients in the community for up to thirty days, is designed to be easy to use by non-experts, to be comfortable and unobtrusive to wear, and to require minimal user and expert intervention. In 2018, we undertook a clinical investigation to evaluate the suitability of the CAVA system in these areas. Seventeen healthy participants wore the device for up to thirty days. Six withdrew prematurely because of a minor skin issue related to the specific electrode pad used with the device, which has since been rectified. Ten participants completed the full trial and answered a questionnaire designed to evaluate their experiences. Their answers revealed that all participants found the device easy to apply and remove by themselves, and found it comfortable and unobtrusive to normal daily activities. A majority found it easy to sleep while wearing the device, and adapted to the presence of the device on their face. Furthermore, the CAVA system was shown to be capable of identifying short periods of induced nystagmus with a high degree of accuracy. In conclusion, the CAVA device functioned well as an ambulatory monitor, with a high level of participant compliance resulting from a number of intentional design features of the device. This work will be of general interest due to the novelty of the device we have developed, but it will also be of specific interest to those interested in balance, dizziness and eye movements.

FP0971Using the CAVA Device to Assess Patients with Meniere’s Disease

John Phillips¹, Jacob Newman², Stephen Cox²

¹Ear, Nose and Throat Dept., Norfolk and Norwich University Hospital, Norwich, UK; ²School of Computing Sciences, University of East Anglia, Norwich, UK

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Until recently, it was impossible to objectively assess a patient’s reports of dizziness without physically observing them during an attack. The CAVA system has made it possible to record the physiological parameters necessary to retrospectively assess patients that report dizziness. This is achieved by way of a medical device worn on the face that simultaneously records head and eye movements. The data captured provides a novel and interesting insight into the disparities between the symptoms reported by patients and the objective signs recorded by the device. During an ongoing clinical investigation of the CAVA system involving patients suffering from dizziness, we recruited three patients who had previously been diagnosed with unilateral Meniere’s disease. All three patients reported rotatory vertigo lasting for hours at a time, severe nausea and plugging in the affected ear. Each patient wore the CAVA device for twenty-three hours a day, for thirty days, and all three reported at least one episode of vertigo during their trial period. Data captured by the CAVA device revealed that only one of the patients had experienced a typical, acute Meniere’s attack, easily identifiable in the data as episodic nystagmus, changing direction over the course of three-hours. One patient experienced short bursts of nystagmus which appeared to be motion-provoked, and the data from the final patient did not reveal any evidence of nystagmus. These results show that the objective signs observed from dizzy patients can be vastly different, despite similar reports of symptoms, and despite similar histories and diagnoses. These findings suggest that an objective measure of a patient’s signs, such as that offered by CAVA, is necessary to correctly assess patients with Meniere’s disease and could significantly change the way in which such patients are managed. For example, it could identify potentially incorrect diagnoses, suggest an alternative diagnosis, or guide the most appropriate treatment options for the patient. These findings will be of interest to those interested in balance, dizziness and eye movements, and specifically to those interested in Meniere’s disease.

FP0975Identification of Stroke and TIA in Patients with Acute Dizziness, Vertigo or Imbalance in Emergency Departments of Primary Care Hospitals: Early Experiences with a Network-based Telemedical Approach

Peter Müller-Barna¹, Christina Leinweber¹, Julia Pfaffenrath¹, Nina Schütt-Becker¹, Rascha von Martial¹, Susanne Greck¹, Nikolai Hubert¹, Holger Rambold^2,3,4, Roman Haberl¹, Gordian Hubert¹

¹TEMPiS telestroke center, Department of Neurology, München Klinik, Academic Teaching hospital of the Ludwig-Maximilians-University, Munich, Germany; ²InnKlinikum Altötting, Department of Neurology, Altötting, Germany; ³Department of Neurology, University of Regensburg, Regensburg, Germany; ⁴MVZ Kliniken Mühldorf, Mühldorf am Inn, Germany

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Background: Acute dizziness, vertigo and imbalance are frequent and difficult to interpret symptoms in the emergency department (ED). Primary care hospitals often lack the expertise to identify stroke or TIA as underlying causes. A telemedical approach based on telestroke networks may offer adequate diagnostics and treatment.

Aim: Aim of this study is to evaluate the accuracy of a novel ED algorithm in differentiating between peripheral and central vestibular causes.

Methods: Within the Telemedical Project for Integrative Stroke Care (TEMPiS) a telemedical application including a videooculography (VOG) system was introduced in 2018 in 19 primary care spoke hospitals. An ED triage algorithm was established for all patients with acute dizziness, vertigo or imbalance of unknown cause (ADVIUC) as a leading complaint. In three predefined months all ADVIUC cases were prospectively registered and discharge letters analyzed. Accuracy of the ED triage algorithm in differentiation between central and peripheral vestibular cases was analyzed by comparison of ED diagnoses to final discharge diagnoses. The rate of missed strokes was calculated in relation to all cases with a suitable brain imaging. Acceptance of teleconsultants and physicians in spoke hospitals was assessed by surveys.

Results: A total number of 388 ADVIUC cases were collected, with a median of 12 cases per months and hospital (IQR 8-14,5). The most frequent hospital discharge diagnoses are vestibular neuritis (22%), stroke/TIA (18%), benign paroxysmal positioning vertigo (18%) and dizziness due to internal medicine causes (15%). Detection of a central vestibular cause by the ED triage algorithm has a high sensitivity (98.6%), albeit poor specificity (45.9%). One stroke out of 32 verified by brain scan was missed (3.1%). User satisfaction, helpfulness of the project, improvement of care, personal competence and satisfaction about handling of the VOG systems were rated consistently positive.

Discussion: The concept shows good acceptance for a telemedical and network-based approach to manage ADVIUC cases in the ED of primary care hospitals. Identification of stroke cases is accurate, while specificity needs further improvement. The concept could be a major step toward a broadly available state of the art diagnostics and therapy for patients with ADVIUC in primary care hospitals.

FP0976The Use of a Gaze Stability Test with Exertion to measure physiological recovery of the vestibular-ocular reflex: a case series

Amy Alexander¹, Shelly Massingale¹, Nicholas Hattrup², Jamie Pardini¹

¹Banner Sports Medicine and Concussion Specialty Clinic; ²Boston University

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Introduction: Following concussion, a graded exercise test can be utilized to measure the autonomic recovery of patients through heart rate, blood pressure, and self-perceived fatigue levels. The gaze stability test (GST) has been observed to decline in individuals following concussion. In addition, the GST acts as a measure of the vestibular-ocular reflex during faster movements, like those occurring during sport activities, and the vestibular-ocular reflex (VOR) has been shown to be unaffected by aerobic activity. With prior studies demonstrating that higher GST values are observed in an athlete population, observing the effect of aerobic activity on GST may reveal subtle lingering deficits during concussion recovery. Therefore, the use of GST with an aerobic exertion protocol may help determine physiological recovery of the VOR. This case series examined the utility of this protocol in a group of athletes recovering from concussion.

Case Description: 16 athletes (7 female) with dizziness and balance symptoms following sport-related concussion (SRC) underwent vestibular physical therapy. Individuals were injured while participating in combat, contact and non-contact sports, with seven patients having no prior history of concussion.

The average time from injury to start of care was 24.5 days (range = 8 - 221) with initial average yaw GST values of 164.81 deg/s in leftward direction movements and 165.0 deg/s in rightward direction movements. Over the course of treatment, athletes completed active rehabilitation consisting of vestibular exercises and aerobic sport specific activity, in clinic and at home. Once athletes achieved higher levels of GST on a subsequent assessment day (average 221.56 deg/s leftward and 223.68 deg/s rightward), they underwent a sport specific aerobic exertion protocol to understand if the VOR declined with aerobic activity. Following the initial exertion protocol, 8 individuals demonstrated a negative decline, ranging from -2.0% to -15.0%, and were not released to return to play. This group continued with vestibular therapy and at the end of treatment, the GST values, on average, were 244.37 deg/s in leftward and 239.66 deg/s in the rightward direction for the entire group of athletes.

Discussion: Assessing GST with exertion may provide a way to evaluate higher-level vestibular dysfunction in athletes following SRC. Having athletes exercise at an intensity that approximates their sport during the SRC recovery process may reveal a functional deficit that does not otherwise appear in traditional assessments. Ultimately, the optimal management of SRC is intended to contribute to safer return to play.

FP0977Gaze Stability in Young Athletes: performance and gender differences

Amy Alexander¹, Shelly Massingale¹, Nicholas Hattrup², Jamie Pardini¹

¹Banner Sports Medicine and Concussion Specialty Clinic; ²Boston University

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Background: Understanding how healthy athletes perform is important to optimally manage recovery from injury, especially in sport related concussion (SRC). Premature return to competition has been associated with an increased risk of orthopedic injury. The gaze stability test (GST) is a functional assessment of the vestibular ocular reflex (VOR), which assesses the maximum velocity a person’s head can move and maintain acuity. This ability relates to better athletic performance for many precision tasks as well as potential avoidance of injury. Studies have established norms in the athlete population, but none have included female athletes, and none have focused on youth athletes.

Methods: 101 (25 female) club sport athletes aged 7 to 17 years (mean age = 13.74 ±2.0) presented to an urban concussion specialty clinic for a multi modal preseason baseline test battery, of which the GST was one element. The clinic protocol used consisted of three tests using Bertec® Vision Advantage: static visual acuity (SVA)-calibrated for 5 ft from laptop screen, visual perception time test (VPT), and yaw GST in the high-performance range (GST-HP) starting at 140 deg/s-as detected by an accelerometer secured to the athlete’s head, with a maximum 400 deg/s. The optotype is 0.2 logMAR larger than SVA, flashed on the screen when the athlete was within an acceptable range of that trial’s intended velocity for 3 turns in a row. GST-HP results are determined by the program’s algorithm.

Results: Average leftward direction head movement for the athletes was 183.55 deg/s (± 41.83) with range = 120-330 deg/s and 191.24 deg/s (± 42.09) with range = 120-280 deg/s in the rightward direction. Consistency indexes within the program indicated that all trials were valid. Analyses using a 2-tailed independent sample t-test determined no significant difference between males and females for either left or right GST (leftward male x¯ = 184.1, female x¯ = 181.8; t = .278, p = .80; rightward male x¯ = 191.9, female x¯ = 189.2; t = .241, p = 0.78).

Conclusions: Each of the Concussion in Sport Group consensus statements underscores the importance of a multidisciplinary approach to managing recovery in the injured athlete. This study adds to the scientific literature by providing objective information on normal GST performance in youth athletes, which should in turn assist clinicians in understanding when an injured athlete has returned to expected levels of function and can safely return to play.

FP0983A Quantitative Analysis of Sway Patterns in Vestibular Assessment using an Open Source Sensor System.

David Ávila-Quezada¹, Haydee Barrientos-Ojeda², Enrique Gallo-Barraza³, Elvis Mancilla-Goldschmidt⁴, Julio Soto-González⁵, Jorge Mardones-Meléndez⁶, María Latorre-González⁷, Ignacia Inarejo-Inarejo⁸

Universidad Austral de Chile

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For the assessment of sway, clinic has a wide range of tests, such as Romberg’s, Fukuda’s stepping, or dynamic gait. However, these are, mostly, subjective and qualitative in character. At present, technological advances have allowed the development of new assessment instruments, such as inertial measurement devices (IMU), which aim to complement the results, from an objective and quantitative point of view. The inertial sensors used to measure acceleration and axial turn in three dimensions, which are then transformed into digital information.

The objective of this investigation, has been to create and test a platform for measuring the body sway and gait disturbance, for its use in vestibular evaluation and/or rehabilitation. The platform used was designed as open source; a model that allows open collaboration, creation of decentralized knowledge, always being in continuous evolution.

Methods: To achieve this objective, a protocol with different tests that contemplated measurements was designed, including: Romberg’s Test, Timed up and go, and walk test. All tests with and without sensor system. 86 subjects were examined, ranging from ages between 19-32 (71 cases), and older than 65 years (15 cases). The selected subjects were individuals without vestibular alterations.

For the evaluation, the equipment was set in the back, between L4-L5.

Results Romberg’s Test: The obtained results were the antero-posterior and lateral oscillations. The obtained values through the sample were 1.1 Hz (sd +-0.7), being within the observed ranges for the oscillations of human movements.

TUG: The results analyzed with the traditional measurement, compared to the IMU evaluation, showed a strong positive correlation (p.96), showing that the equipment measurements can replace the chronometer measurements. Also, a graph that allows for posterior analysis and extraction of more data was obtained (see fig. 1).

Figure 1:

TUG results.

Walk test: The results obtained in this test showed a strong correlation (p .9), between the analogue observation and the IMU evaluation. Nonetheless, the most important result was the characterization of the march oscillations (see fig. 2).

Figure 2:

Cyclical pattern of march phases.

Conclusions: The obtained results allowed us to describe patterns of the different tests used in Vestibular Assement with IMU. At present, we are increasing the studied population; also, regression formulas are being worked on, to determine possible alterations in patterns.

For more information and download or sponsor this project, please visit https://github.com/Debaq/Fullaxis

FP0988Are gain values significantly altered by manual data selection when performing the video Head Impulse Test on all six semicircular canals with two different v-HIT systems?

Abrahamsen^1,2, Regitze Skals³, Dan D. Hougaard^1,2

¹Department of Otolaryngology, Head & Neck Surgery and Audiology, Aalborg University Hospital, Aalborg, Denmark; ²Department of Clinical Medicine, Aalborg University, Aalborg, Denmark; ³Unit of Clinical Biostatistics and Bioinformatics, Aalborg University Hospital, Aalborg

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Background: It has not yet been tested whether mean gain values and the presence of pathological saccades are significantly altered by manual data selection or if data selection done by the incorporated software detection algorithms alone provides a reliable data set following video head impulse testing (v-HIT).

Methods: 120 subjects with neither vestibular nor neurological disorders underwent four separate tests of all six SCCs with either EyeSeeCam® (Interacoustics©, Middelfart, Denmark) or ICS Impulse® (Otometrics©, Taastrup, Denmark). All v-HIT test reports underwent manual data selection by an experienced ENT Specialist with deletion of any noise and/or artifacts. A paired T-test comparing mean gain values based upon unsorted data gain values and sorted data gain values was performed.

Results: EyeSeeCam®: Horizontal semicircular canals (SCCs): The estimate and the p-value for respectively the right lateral SCC and the left lateral SCC were 0.00088 (0.69) and 0.00004 (0.95). Vertical SCCs: The estimate varied from -0.00858 to 0.00637 with p-values ranging from 0.27 to 0.79. ICS Impulse®: Horizontal SCCs: The estimate and the p-value for respectively the right lateral SCC and the left lateral SCC were 0.00071 (0.26) and 0.00159 (0.06). Vertical SCCs: The estimate varied from 0.00217 to 0.01357 with p-values ranging from 0.00 to 0.05. Based upon the mean gain value from the individual SCC being tested, 148 tests before and 127 after manual data selection were considered pathological.

Conclusion: None of the two v-HIT systems revealed any clinically important effects of manual cleaning. However, 21 fewer tests were considered pathological following manual data selection.

FP0992V-HIT in darkness

Paz Pérez-Vázquez¹, Virginia Franco-Gutiérrez²

¹Hospital Universitario de Cabueñes, Gijón, Spain; ²Hospital Universitario Lucus Augusti, Lugo, Spain

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Background: The earliest components of the Head Impulse Test (HIT) (within 70-80 ms of the onset of head rotation) are controlled by the vestibulo-ocular reflex (VOR), complemented by the optokinetic and pursuit systems, with a relatively long delay (70-80 ms).

The purpose of this study was to evaluate the possibility of individualizing the VOR contribution to the V-HIT.

Methods: Thirty-six healthy individuals (19 males, 17 females; age 21-64 years, mean 39 years) underwent horizontal video HIT (vHIT). This was first conducted in darkness (covering the eyes with an adapted opaque cap) without visual target and then visually tracked.

An EyeSeeCam device (software version 1.3.0.008, Interacoustics, Denmark) was employed for both paradigms.

Results: After rejecting artifacts, 691 (342 right, 349 left) impulses in darkness and 886 (434 right, 452 left) impulses visually guided were analyzed. Seventy per cent of the impulses performed in darkness delivered ocular responses opposite to the head direction, matching its velocity to a point where a quick anti-compensatory eye movement (SQEM) stopped the response; of these, 75% recaptured the head velocity after culmination. Thirty per cent of the responses completed a bell-shaped curve. SQEM mean latency was 58.21 ms (interquartile range 60-67 ms)

Men and women showed different behavior: Females completed more bell-shaped curves than males (42 vs 15%, respectively; p=0.01). SQEM latency was longer (62.81 vs 55,71 ms; p<0.01) and time to recapture the bell-shaped curve was shorter (77.51 vs 92.52 ms; p<0.01) in females than in males.

When comparing vHIT responses in darkness and in the visually guided test, the completed bell-shaped curve gains and instantaneous gains (at 40, 60 and 80 ms) before SQEM were equivalent for both paradigms, as well as regression gains. Men and women showed comparable gains in both paradigms.

Conclusions: Lateral canals VOR effect can be localized in the first 70 ms of the responses. HIT paradigm responses seem to be not only influenced by vision and other influences, pre-programing the response, might be contemplated. Since gender quantitative differences related to functional test have not been stated, the qualitative differences founded in this study led to consider the significant relationship between vestibular function, particularly horizontal canal function, and topographical memory that has been previously demonstrated. Interestingly, topographical memory tests have shown large differences between males and females.

FP0995Aetiology, diagnosis and management of vestibular disorders in children

Sudhira Ratnayake

Alder Hey Children’s NHS Foundation Trust/University of Liverpool, Liverpool, United Kingdon

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Vestibular disorders in children are significant causes for childhood morbidity with various manifestations that are often unrecognised or undiagnosed. Dizziness/vestibular symptoms are usually managed by paediatricians and paediatric neurologists or neurotologists and surgeons who primarily deal with adults. Dedicated paediatric neurotologists require training in all aspects of paediatric diseases for a holistic approach for management that is crucial for best outcomes.

The aetiological profile for peripheral and central disorders is markedly different from that in adults. For example, vestibular migraine is the commonest paediatric vestibular affliction; third window disorders in children may follow a different course than adults; idiopathic Meniere’s disease and benign positional paroxysmal vertigo are very rare and a third of sencorineural hearing losses due to any cause is also accompanied with a vestibular deficit. The diagnostic algorithm with latest technology is also different as children are far more difficult to obtain anamnesis from and to test as compared to adults. Examining a child is really an art that can come from years of experience and the knowledge about the paediatric vestibular system and its development. Following diagnosis, treatment might follow a different trajectory than adults and it is important to acknowledge this. It is also important to recognise the close overlap with paediatric neurology and indeed, a robust knowledge in neurology is essential to practice paediatric neurotology.

This presentation includes a brief overview of no more than 8 minutes of the developing paediatric vestibular system in children, aetiology of paediatric vestibular disorders, the diagnostic process with evidence based latest methods and their management. The differences in paediatric vestibular diagnosis and disease profiles as compared to adults are also highlighted from the authors’ personal series. The target audience is neurotologists who practice vestibular medicine, audiologists and audiological scientists, physiotherapists and neurologists.

FP0996Development of a diagnostic framework for vestibular causes of dizziness and unsteadiness in patients with mitochondrial disease – A Delphi consensus

Amanda Male^1,2; Sarah Holmes³; Ros Quinlivan³; Michael Hanna³; Robert D.S. Pitceathly³; Gita Ramdharry³; Diego Kaski²

¹Therapy Services, The National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, United Kingdom; ²Department of Clinical and Movement Neurosciences, University College London, Queen Square, London, WC1N 3BG, United Kingdom; ³MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital of Neurology and Neurosurgery, Queen Square London, WC1N 3BG, United Kingdom

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PURPOSE: Mitochondrial diseases are a diverse group of genetic conditions for which limited treatment options exist. Adult mitochondrial disease (MD) is among the commonest adult form of inherited neurological disorders. Unsteadiness is a commonly reported problem for adults with MD, and is frequently attributed to ataxia and/or peripheral neuropathy.

Holmes et al 2018, identified benign paroxysmal positional vertigo (BPPV), peripheral vestibulopathy and vestibular migraine as frequent causes of unsteadiness and dizziness in adults with MD. Each of these diagnoses require specific diagnostic tests and management, including vestibular rehabilitation.

Vestibular diagnoses are commonly missed so we aimed to develop a diagnostic framework to enable earlier diagnosis. We used consensus methods to guide the diagnostic questions included in the framework.

METHODS: A modified electronic Delphi approach was used comprising three rounds. Round one developed the statements from research evidence-based literature, for BPPV, peripheral vestibulopathy and vestibular migraine. The statements were emailed by the secretary to members of the European Academy of Neurology (EAN), specialist panel of neuro-otologists. Two emails were sent each round.

Specialists were asked to rate how much they agreed or disagreed with the statements being included in the framework using a six-point scale (0=strongly agree, 5=strongly disagree). Respondents could also suggest any rewording to be considered for the next round if consensus was not met.

Consensus per statement was defined when >75% of the responses were in the lower or higher tertile (Boulkedid et al., 2011). Only the statements that did not reach consensus were recirculated in round three.

RESULTS: Twenty nine percent of EAN members replied to round two (n=12) and 24% for round three (n=10). Twelve statements were emailed in round two, with five reaching consensus. Four were removed for round three due to the comments from specialists that they were not sensitive enough to discriminate multiple causes of dizziness. Three statements were reworded for round three, with only one reaching consensus. A total of six statements were included in the diagnostic framework.

CONCLUSION: A modified Delphi study has identified key questions to ask patients with mitochondrial disease reporting dizziness and unsteadiness, in order to identify vestibular causes. These questions have been included in a diagnostic framework that will be validated in an observational cohort study design.

FP1002The Interplay between Bone Mineral Density and Meniere’s Disease

Avi Shupak^1,2, Nabil Faranesh¹

¹Unit of Otoneurology, Lin and Carmel Medical Centers; ²Faculty of Social Welfare and Health Sciences, The University of Haifa

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Background: Previous studies have reported an association between reduced bone mineral density and the occurrence of benign paroxysmal positional vertigo, balance impairment, and saccular dysfunction. Also, the results of recent animal studies have raised the possibility that vestibular dysfunction could affect bone remodeling and bone mass. The goal of the study was to compare bone mineral density of patients suffering from definite Meniere’s disease to that of a matched control group.

Subjects and Methods: The study group included 23 patients suffering from definite Meniere’s disease and the control group 23 patients matched in their race, gender and age parameters in whom no vestibular pathology could be found. Dual energy x-ray absorptiometry of the femoral head was used for the assessment of bone mineral density.

Results: The average T scores were -1.53±1.08 in the study and -0.39±0.72 (P=0.016) in the control group and the Z scores -0.4±0.63 and 0.33±0.31 (P=0.018) respectively. 17 patients (74%) of the study group and 9 (39%) of the control had T scores less than -1.0 indicating osteopenia/osteoporosis (P=0.036).

Conclusions: The results show significant association between Meniere’s disease and reduced bone mineral density of the femoral head. Bone mineral density studies of the weight bearing bones are warranted in Meniere’s disease for the early diagnosis and treatment of osteopenia/osteoporosis on one hand and possible benefit of this treatment on Meniere’s diseases evolution on the other hand.

FP1007Screening Measures and Prediction of Vestibular Diagnostic Test Results

Helen S Cohen¹, Haleh Sangi-Hahgpeykar², Megan Watts¹, Alex D Sweeney¹, Angela S Peng¹, Nathan Silver¹

¹Departments of Otolaryngology - Head and Neck Surgery, Baylor College of Medicine, Houston, TX, USA; ²Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX, USA

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Background: Many patients come for care of “dizziness” with vague complaints, not all of which are true vertigo or oscillopsia. Many patients, especially seniors, have multiple health problems. Some of those problems cause symptoms that patients may associate with vestibular disorders, even though they may not be related. Because some patients may not understand the questions they may give misleading answers to questions that clinicians ask patients during the initial visit.

Objective: The goal of this study was to determine if some screening measures are useful for predicting the presence of vestibular impairments as indicated by results of objective diagnostic tests of the vestibular system.

Methodology: This retrospective study examined electronic medical records of 150 adult patients who had visited a neurotologist and were then referred for the complete objective vestibular test battery (VNG). We noted blood pressure and pulse as measured by the clinic nurse, responses to screening questions asked by the neurotologist, and outcome of the VNG.

Results: Blood pressure in the range of Stage 2 hypertension and responses to the question about vertigo predicted abnormal VNG responses. Pulse, blood pressure in the range of Stage 1 hypertension, and responses to questions about balance, lightheadedness and oscillopsia did not predict VNG outcome. Subjects with blood pressure in the range of Stage 2 hypertension had high rates of diabetes and diagnosed hypertension diagnosed by primary care physician or cardiology.

Conclusions: Clinicians can use these two responses, very high blood pressure as measured in the clinic by a nurse and responses to questions about vertigo, to help decide whether or not a VNG is indicated. Other screening measures may not be so useful.

Supported by NIH grant 2R01-DC009031

FP1011Otoneurological manifestations and VHIT findings in CANVAS

Emilio Ruiz Fernandez², Laura Rebolledo Bernad¹, Ernesto Sanchez Llanos¹, Diego Casas Sanz¹, Jose Gazulla Abio², Jesus J. Fraile Rodrigo¹

¹Otorhinolaryngology Department, Miguel Servet University Hospital, Zaragoza, Spain; ²Neurology Department, Miguel Servet University Hospital, Zaragoza, Spain

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Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) is a neurodegenerative disease that causes progressive imbalance. The sensory deficits found in this syndrome have been attributed to a neuronopathy, that would affect the Scarpa’s ganglion, leaving the spiral ganglion unaffected. We present a prospective study describing the characteristics and otoneurological manifestations of four patients meeting CANVAS criteria, two women and two men. Age ranged from 60 to 83 years. All patients underwent neurological and otoneurological examination using videonystagmography and vHIT. Two of them had been previously identified as carriers of a biallelic expansion of an intronic repeat in the RFC1 gene. All four patients showed progressive cerebellar ataxia, lower limb proprioceptive sensory loss, dysarthria and unsteady gait. Two patients had spasmodic cough at the symptom debut. The otoneurological examination found a bilateral vestibulopathy in all of them, as well as downbeating nystagmus and gaze nystagmus. Audiometry test showed moderated mixed hearing loss in all four patients, with symmetrical sensorineural hearing loss related to old age. There was no relationship between the progression of the disease and the hearing impairment. Our findings confirm the association of bilateral vestibulopathy and preserved hearing in CANVAS patients, although further research is needed to fully describe the phenotype of the disease. In our opinion, vHIT is a useful test to identify the global and bilateral vestibulopathy in a systematic and objective way.

FP1012Change of VOR gain after surgical plugging in superior canal dehiscence syndrome

Ja-Won Koo¹, Jaehong Park², Sang-Yeon Lee¹

¹Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea; ²Wirye Hana Otorhinolaryngology Clinic, Seongnam, Korea

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Background: Superior semicircular canal dehiscence (SCD), which is characterized by a “third mobile window” in the inner ear, causes various vestibular and auditory symptoms and signs. Surgical plugging of the superior canal (SC) can eliminate the symptoms associated with increased perilymph mobility due to the presence of the third window. However, the natural course of vestibular function after surgical plugging remains unknown. In this study, we explored longitudinal vestibular function after plugging surgery in subjects with SCD.

Materials and Methods: A total of 11 patients, who underwent SCD repair via middle fossa approach were included in this study. Changes in vestibulo-ocular reflex (VOR) gain in all planes were measured over 1 year with the video head impulse test. We also evaluated surgical outcomes, including changes in symptoms, audiometric results, and electrophysiological tests, to assess whether plugging eliminated third mobile window effects.

Results: The mean VOR gain for the plugged SC decreased from 0.81 ± 0.05 before surgery to 0.65 ± 0.08 on examinations performed within 1 week after surgery but normalized thereafter. Four of seven subjects who were able to perform both VOR tests before surgery and immediately after surgery had pathologic values (SC VOR gain < 0.70). Conversely, the mean VOR gain in the other canals remained unchanged over 1 year. The majority of symptoms and signs were absent or markedly decreased at the last follow-up evaluation, and no complications associated with the surgery were reported. Surgical plugging significantly attenuated the air-bone gap, in particular at low frequencies, because of increased bone conduction thresholds and deceased air conduction thresholds. Moreover, surgical plugging significantly increased vestibular-evoked myogenic potential thresholds and decreased the ratio of summating potential to action potential in plugged ears. Postoperative heavily T2-weighted images were available for two subjects and showed complete obliteration of the T2-bright signal intensity in the patent SC lumen in preoperative imaging based on filling defect at the site of plugging.

Conclusion: Our results suggest that successful plugging of dehiscent SCs is closely associated with a transient, rather than persistent, disturbance of labyrinthine activity exclusively involved in plugged SCs.

FP1013Quantitative three-dimensional image analysis of the superior canal after surgical plugging of superior semicircular canal dehiscence

Ja-Won Koo¹, Sang-Yeon Lee², Won-Ki Jeong³

¹Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam; ²Department of Otorhinolaryngology, Seoul National University Hospital, Seoul, ³Department of Computer Science and Engineering, Korea University, Seoul, Korea

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Background: Surgical plugging to treat superior semicircular canal dehiscence (SCD) has been proven to impede the effect of the third mobile window, abating cochleovestibular symptoms. Knowledge of superior semicircular canal (SC)-plugging status has been proposed to serve as a guide for adjuvant treatment. Here, we investigated disturbances in the inner ear fluid space following SC plugging using a novel three-dimensional (3D) reconstruction-based method.

Methods: The study was conducted in 7 subjects who had undergone surgical plugging of SC via MFA. MRI examination were performed around 1 year after surgery using a 3 T MR scanner. 3D images were reconstructed by combining manual segmentation of the labyrinth and an automatic thresholding algorithm to visualize the surgical plugging status of a dehiscent SC. In this process, assessment of the 3D volume of the SC plugging and its application to interpret the clinical results are indispensable. This approach used a semi-automatic segmentation algorithm and a direct volume rendering method derived from conventional magnetic resonance images. The variable extents of filling defects at the sites of SC plugging and the positional relation of the defect to the ampulla and common crus were identified.

Results: The success group exhibited markedly reduced volumes following surgery, whereas one subject who could not achieve surgical resolution displayed no changes in volume. These results indicate that the success or failure of SC plugging was related to 3D volume changes in the labyrinth fluid signal. Sparing ampulla in success group seems to be related to restored VOR gain after surgery.

Conclusion: This study presents individualized SC-plugging statuses using a novel 3D reconstruction-based method and it facilitates future work regarding easy-to-measure 3D volume changes. This current technology also aids in the exploration of pathologic changes in various targets of interest.

FP1015Abnormal sense of self in a cohort of patients with otoneurological disorders: clinical features and precipitating factors

Maya Elzière^1,2, Marco Bressan³, Christophe Lopez¹

¹Laboratoire de Neurosciences Cognitives, CNRS and Aix-Marseille University, Marseille, France; ²Centre des Vertiges, Hôpital Européen de Marseille, Marseille, France; 3 Laboratoire de Psychologie Cognitive, CNRS and Aix-Marseille University, Marseille

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An increasing number of reports indicates that vestibular disorders evoke deficits reaching far beyond postural and oculomotor reflexes, including deficits in cognition and affective control, resulting in severe everyday life limitations. Pioneering work in otoneurology and epileptology have associated vestibular disorders with disturbances in the sense of self and own-body representations. Among the most consistently reported symptoms are sensations resembling depersonalization-derealization (DD) – indicating a sense of unreality and estrangement of the self ; out-of-body experiences or Alice in Wonderland syndrome. However, research into these phenomena was mostly based on case reports or small patients groups lacking proper otoneurological examination. Research has poorly described the relation between different etiologies of dizziness and vertigo, comorbidities such as migraine, anxiety and depression, with the sense of self.

The aims of this prospective, observational study was to compare DD symptoms in 390 patients with dizziness/vertigo with 390 age- and sex-matched participants with no history of dizziness/vertigo. The DD was evaluated using the Cambridge Depersonalization Scale from Sierra and Berrios (2000). We analyzed precipitating factors of DD such as sociodemographic data, history of the disease, frequency of vertigo/dizziness, clinical parameters from otoneurological examination, anxiety and depression.

The total DD score was significantly higher in patients than in controls. Symptoms of DD in patients were reported as significantly more frequent and to last significantly longer than in controls. 12% of patients with dizziness had scores above the cut-off point for DD, whereas only 2% of controls had scores above the cut-off point, in line with DD prevalence in the general population. Among patients, DD intensity increased significantly with the frequency of vertigo/dizziness, but DD intensity did not differ significantly between etiologies of vertigo/dizziness.

The structure of DD symptoms was analyzed using an exploratory factor analysis, which revealed 4 components (distorted body and self experience, distorted subjective recall, numbing, perceptual alterations). A mediation analysis indicated that between 39% (distorted body and self experience) and 100% (distorted subjective recall) of the observed differences in DD components scores between the two groups are explained by the mediation effect of anxiety and depression.

In conclusion, DD is not a rare phenomenom in otoneurological populations. Anxiety and depression mediate most of the differences between DD intensity in patients and controls, probably in line with the frequency of the perceptual incoherence created by multisensory misintegration in the brain during vertigo/dizziness.

FP1020Functional Head Impulse Testing Might Be Useful for Assessing Vestibular Compensation After Unilateral Vestibular Loss

Julia Sjögren, Per-Anders Fransson, Mikael Karlberg, Måns Magnusson, Fredrik Tjernström

Department of Clinical Sciences, Otorhinolaryngology Head and Neck Surgery, Skåne University Hospital, Lund University, Lund, Sweden

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Background: Loss of the vestibulo-ocular reflex (VOR) affects visual acuity during head movements. Previous studies have shown that compensatory eye-saccades improve visual acuity and that the timing of the saccade is important. Most of the tests involved in testing VOR are made with passive head movement, that do not necessarily reflect the activities of daily living and thus not being proportionate to symptoms and distresses of the patients.

Objective: To examine differences between active (self-generated) or passive (imposed by the examiner) head rotations while trying to maintain visual focus on a target.

Method: Nine subjects with unilateral total vestibular loss were recruited (4 men and 5 women, mean age 47) and tested with video Head Impulse Test (vHIT) and Head Impulse Testing Device-Functional Test (HITD-FT) during passive and active movements while looking at a target. VOR gain, latencies of covert saccades, frequency of covert saccades and visual acuity were measured and analyzed.

Results: Active head-impulses toward the lesioned side resulted in better visual acuity (p = 0.002) compared to conventional passive head-impulses and generated eye-saccades with significantly shorter latencies (p = 0.004). Active movements to the lesioned side generated dynamic visual acuities that were as good as when testing the intact side.

Conclusion: Actively generated head impulses resulted in normal dynamic visual acuity, even when performed toward the side of total vestibular loss. This might be attributed to the appearance of short-latency covert saccades. The results show a strong relationship between self-generated movements, latencies of covert saccades and outcome in HITD-FT, i.e., a better dynamic visual function with less retinal slip which is the main function of the VOR. The method of active HITD-FT might be valuable in assessing vestibular compensation and monitoring ongoing vestibular rehabilitation.

FP1023AQEM: a Marker of Peripheral Involvement in the Acute Vestibular Diseases

Enrico Armato, Marta Mion, Andrea Castellucci

San Giovanni e Paolo Hospital, Venice; Santa Maria della Misericordia, Rovigo; Arcispedale Santa Maria Nuova, Reggio Emilia

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Background: with the term AQEM (Anticompensatory Quick Eye Movements) we define some anticompensatory saccades detected during video Head Impulse Test (vHIT) examination on the healthy side in patients with an acute peripheral vestibular disease (APVD). AQEM can be considered a sign of peripheral involvement in cases of spontaneous nystagmus and can be found in many vHIT tracks, though usually neglected by examiners.

Methods: we retrospectively analyzed 60 vHIT tracks of patients presenting to our attention with acute vertigo.

Results: AQEM occurred in 30 patients (50%). Mean latency was 338.33 ± 24.76 msec. 55% of cases had a history consistent with recent acute rotatory vertigo. 75% of patients presented with horizontal spontaneous nystagmus in hibited by visual fixation and 90% of vHIT documented a specific and isolated impairment of the vestibulo-ocular re flex (VOR) for horizontal canals. AQEM on one side were associated with lower VOR-gain on the contralateral ear (p < 0.0001). 24 patients among 30 cases exhibiting AQEM underwent neuroimaging and none of them showed central nervous system (CNS) pathologies.

Conclusions: standard profile of AQEM can be summarized as follows. VOR-gain is close to zero for horizontal canal contralateral to the affected side. Typically, there is a spontaneous nystagmus inhibited by visual fixation. Patients mostly present a history of recent acute rotatory vertigo. Mainly horizontal canals are involved. AQEM seem to represent a transient finding. In contrast to few works dealing with this subject, we found very broader and heterogeneous categories of patients, though most of them did not show CNS involvement. AQEM could represent an interesting marker of APVD.

FP1024Etiologic Distribution of Dizziness and Vertigo

Hyo-Jung Kim, PhD¹, Ja-Ok Lee, MSc², Jeong-Yoon Choi, MD, PhD^2,3, Ji-Soo Kim, MD, PhD^2,3

¹Research Administration Team, Seoul National University Bundang Hospital, Seongnam, Korea; ²Dizziness Center, Seoul National University Bundang Hospital, Seongnam, Korea; ³Department of Neurology, Clinical Neuroscience Center, Seoul National University Bundang Hospital, Seongnam, Korea

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Objectives: This study aimed to determine the etiologic distribution of dizziness and vertigo in a referral-based dizziness clinic in South Korea.

Methods: We analyzed the diagnoses of 21,166 consecutive dizzy patients (12,691 women, mean age = 57.9±15.7) seen from 2003 to 2019 using a registry and medical records. Overall, dizziness and vertigo were more common in women (60.0%, CI=0.59~0.61) than in men without a difference in age (57.7±15.5 vs. 58.1±16.1, p=0.094).

Results: Benign paroxysmal positional vertigo (BPPV, 24.1%) was the most common cause of dizziness/vertigo, followed by psychiatric or persistent postural perceptual dizziness (20.8%), vascular disorders (12.9%), vestibular migraine (10.2%), Meniere’s disease (7.2%), vestibular neuritis (5.4%). These six disorders comprised more than 80% of all disorders. The etiology could not be determined in 5.0%, and more than one etiology were found in 14.1%. Vestibular migraine was the most common disorder in children and adolescents (<19 years), psychiatric or persistent postural perceptual dizziness (26.3%) in the adults (19-64 years), and BPPV (28.2%) in the elderly (= 65 years). We estimated the number of hospital visits due to dizziness/vertigo in South Korea in 2050 using the data from the KOSIS and the Healthcare Bigdata Hub (health insurance review & assessment service in South Korea). 3,974 visits per 100,000 of general population in 2019 and 6,057 in 2050, an increase of 52% over the years.

Conclusion: This etiologic distribution is similar to that reported in another country, and indicates no significant differences in the proportion of diseases causing dizziness and vertigo across different ethnic groups. This study provides valuable information to establish healthcare policy for dizziness and vertigo.

FP1029The use of smartphones in the treatment of MdDS and other vestibular disorders

Michiel Carpentier, Jan Van Riel

MdDS Reset

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MdDS Reset was founded by Jan Van Riel and Michiel Carpentier.

Jan Van Riel is a software engineer and a serial entrepreneur. He holds over 30 software patents and has co-founded five startups, several of which had very successful exits. He co-founded startup Twintag, where he is also still active as both as Chairman of the Board and software engineer.

After disembarking from a long flight, somewhere in 2018, Jan kept feeling swaying emotions when sitting still, as if he would still be on the plane. This condition now seemed permanent, sometimes somewhat better and then a few days later again worse. This was the third incident in a decade. Not a single doctor could tell him what was wrong. He was tested extensively yet nothing could be found.

Finally he was diagnosed with MdDS by Prof. Floris Wuyts of the University of Antwerp, a Bárány Society member. Prof. Wuyts also proposed optokinetic treatment in an optokinetic (OKN) booth. While receiving treatment in October 2019, Jan realised that there should be an easier way to deliver such optokinetic stimuli, using a simple smartphone mounted inside VR glasses.

After some discussions with Michiel Carpentier, a longtime colleague and associate of Jan, they decided to found a company in March 2020 to develop such a treatment. Towards the end of 2021 the product was ready for release, and a prototype of the software was tested by Floris Wuyts and Catho Schoenmaekers, who is doing an elaborate clinical trial of the mask, comparing it with the OKN booth (see separate free paper form submitted by Catho).

During the development many different improvements were discovered, as well as other possibilities of smartphone technology as a medical device, like e.g. using a smartphone’s sensors to objectively measure a Romberg balance test, or creating a treatment for Visually Induced Dizziness (VID).

Next to the treatment, all data gathered by the smartphone sensors is being stored in a big data platform (while respecting patient’s privacy) and can be made available for further research.

The submitter would like to present our first findings of actual patients using the device, as well as gather feedback from the audience.

FP1030Implementation of a vestibular test within a hearing screening program.

Background: Postural control depends on the integration of visual, vestibular and proprioceptive information. Balance and vestibular disorders in adults are well studied, but we know less about them in children. Although motor and balance function in children is still under development throughout childhood, the vestibular function is present at birth and becomes fully integrated in puberty. A vestibular assessment in infants and children is increasingly required in clinical practice especially in those undergoing cochlear implantation and children with delayed motor skills.

Methods: We propose a child-friendly method to screen the vestibular function along with the hearing screening program based on an application of cervical Vestibular Evoked Myogenic Potentials (cVEMP), induced by a vibratory stimulus and a stimulus delivery protocol regulated by the activity level of cervical muscles.

According to our feasibility study it is possible to test the vestibular function on a large scale in newborns and infants with cVEMP. cVEMP was used alongside the Stockholm Newborn Hearing Screening Programme in newborns that did not pass the hearing screening. cVEMP were obtained by mastoid stimulation with bone conducted tone burst at safe intensity levels and with a stimulus delivery regulated by the electromyographical (EMG) levels at the site of recording. Fifty infants were tested. cVEMP was defined as a short latency positive-negative electromyographic (EMG deflection), with a 12–17 ms positive peak (p1) and 20–25 ms the negative peak (n1) after stimulus. cVEMP could be completed in the majority of the children (86% and 97% in optimized test conditions) and a response identified in 73% of the tested ears (91% in optimized test conditions). The control of muscle activity under recording was the most critical factor to obtain responses with readable results. We also propose a technique to optimise the neck muscle activity under recording

Conclusions: Our results support the use of cVEMP as a vestibular screening tool in infants along with hearing screening programs.

FP1031The Relation Between Migraine and BPPV Characteristics

Pinar Yalinay-Dikmen¹, Ozlem Gedik-Soyuyuce², Alper Ozdilek³, Nazim Korkut⁴

¹Acibadem Mehmet Ali Aydinlar University Neurology Department; ²Acibadem Maslak Hospital Audiology Department; ³Acibadem Mehmet Ali Aydinlar University ENT Department; ⁴Acibadem Maslak Hospital ENT Department

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Objectives: Benign paroxysmal positional vertigo (BPPV) is the most common type of vertigo and the patients with migraine tend to experience various subtypes of BPPV. This study was designed to describe the relation between Migraine and BPPV characteristics in 2610 patients diagnosed with BPPV in our vertigo center in three years.

Materials and Methods: We retrospectively analyzed the records of 2610 patients (1705 female, 905 male; age range: 2-95 years, mean age 47.71±16.57) diagnosed with BPPV in the vertigo center of a tertiary hospital. BPPV diagnosis of all patients was made by using videonystagmography (VNG). BPPV was characterized by the presence of short-lasting positional vertigo with and/or without visual fixation induced by diagnostic tests specific for each semicircular canal. The migraine evaluation in all BPPV patients was done by a neurologist. None of the patients included in the study had central nervous system pathology.

Results: Migraine was diagnosed in 20.22% of all patients. Coexisting motion sickness was present in 94% of the migraine patients and was present in 40.8% of all patients. A recent history of trauma was present in 0.88%. Coexisting vestibular neuritis (VN) was present in 7.20%, coexisting Meniere’s Disease (MD) was present in 1.72% and coexisting labyrinthitis was present in 0.26% of all BPPV patients. The most common semicircular canal involvement in BPPV was the posterior with 60.45%. The other canal involvements were 30.61% lateral, 8.46% multiple and 0.45% anterior respectively. The right ear was affected in 32.83%, the left ar was affected in 30.80% and both ears were affected in 36.36%. Spontaneous nystagmus was observed in 11.57% of all patients and in 7.76% of the migraine patients; pseudo-spontaneous nystagmus was observed in 2.75% of all patients and in 1.89% of the migraine patients. All patients were successfully treated by canal-specific repositioning maneuvers. An average of 1.82±1.40 maneuvers were necessary for the complete abolition of positional nystagmus without visual fixation. The recurrence rate of BPPV was 34.71%. Our study demonstrated a positive correlation between migraine and the recurrence rate (p=0.000), a positive correlation between migraine and spontaneous nystagmus (p=0.001), but no correlation between migraine and the number of maneuvers necessary for complete recovery (p=287).

Conclusions: The clinicians should be aware of the coexistance of both migraine and BPPV in the same patient to enhance the diagnosis and management of recurrent spontaneous vertigo.

The target audience would be all vestibular specialists.

FP1032Analysis of the effectiveness of the prophylaxis of vestibular migraine depending on the diagnostic category and the prescribed drug

Emilio Domínguez-Durán¹, María Alharilla Montilla-Ibáñez², María Guadalupe Álvarez-Morujo de Sande³, Esther Domènech-Vadillo⁴, Carmen Bécares-Martínez⁵, Rocío González-Aguado⁶, Gloria Guerra-Jiménez⁷

¹Hospital QuironSalud Infanta Luisa, Sevilla, Spain; ²Complejo Hospitalario de Jae’n, Jae’n, Spain; ³Hospital Universitario Puerta del Mar, Ca’diz, Spain; ⁴Hospital Universitari Joan XXIII, Tarragona, Spain; ⁵Hospital Universitario de Torrevieja, Torrevieja, Spain; ⁶Hospital Universitario Marque’s de Valdecilla, Santander, Spain; ⁷Complejo Hospitalario Universitario Insular Materno-Infantil, Las Palmas de Gran Canaria, Spain

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Introduction: Vestibular migraine (VM) consists of recurrent episodes of vestibular symptoms that are accompanied by migraine in at least 50% of the episodes. The criteria of the Ba’ra’ny Society include two diagnostic categories: “actual” vestibular migraine and probable vestibular migraine. There is a wide range of drugs that can be prescribed for the prophylactic treatment of VM, but recommendations for the selection of the most appropriate drug are currently lacking. Objective: To measure the extent to which the prophylactic treatment of VM reduces vestibular symptoms, headache and the number of crises depending on the diagnostic category of the Ba’ra’ny Society and the drug used for prophylaxis.

Material and methods: This is a multicenter prospective study. Patients with VM who presented to any of the participating centers and who subsequently met the VM criteria were prescribed one of the following types of prophylaxis: acetazolamide, amitriptyline, flunarizine, propranolol or topiramate. Patients were called back for a follow-up visit 5 weeks later. This allowed the intensity of vestibular symptoms, headache and the number of crises before and during treatment to be compared.

Results: 31 Patients met the inclusion criteria. During the treatment, all the measured variables decreased significantly. In a visual analogue scale, the intensity of vestibular symptoms decreased by 45.8 points, the intensity of headache decreased by 47.8 points and patients suffered from 15.6 less monthly crises compared to the period before the treatment. No significant between-group differences were found when patients were divided based on their diagnostic category or the choice of prophylaxis prescribed to them.

Conclusion: Five weeks after the prescription of the treatment of VM, a reduction of their symptoms and crises was observed with no significant differences based on patients’ diagnostic categories or the choice of prophylaxis prescribed to them.

FP1033Exploring the frontiers of vestibular migraine: A case series

Emilio Domínguez-Durán¹, Esther Domènech-Vadillo², Carmen Bécares-Martínez³, María Alharilla Montilla-Ibáñez⁴, María Guadalupe Álvarez-Morujo de Sande⁵, Rocío González-Aguado⁶, Gloria Guerra-Jiménez⁷

¹Hospital QuironSalud Infanta Luisa, Sevilla, Spain; ²Hospital Universitari Joan XXIII, Tarragona, Spain; ³Hospital Universitario de Torrevieja, Torrevieja, Spain; ⁴Complejo Hospitalario de Jae’n, Jae’n, Spain; ⁵Hospital Universitario Puerta del Mar, Ca’diz, Spain; ⁶Hospital Universitario Marque’s de Valdecilla, Santander, Spain; ⁷Complejo Hospitalario Universitario Insular Materno-Infantil, Las Palmas de Gran Canaria, Spain.

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Introduction: Patients with episodic vestibular syndrome (EVS) whose symptoms resemble those of vestibular migraine (VM) but who do not meet the criteria for it are common. Objective: To describe those patients suffering from EVS in whom defined etiologies have been ruled out in order to determine if their symptoms can be linked to VM.

Material and methods: Prospective multicenter study. The medical records of patients with VM and patients with EVS suggestive of VM but not meeting the criteria for it were examined. The characteristics of headache, the number and the length of attacks, the association of vestibular symptoms and headache, the intensity of symptoms and the response to treatment were recorded.

Results: 58 patients met the criteria for VM or probable VM; 30 did not. All of the symptoms improved significantly in the treated patients with VM or probable VM; in the rest of the treated patients, only the vestibular symptoms improved.

Conclusion: A subgroup of patients that cannot be attributed to any known vestibulopathy according to present day VM criteria profited from migraine treatment, suggesting that their vestibular symptoms belong to the migraine.

FP1034Persistent Postural-Perceptual Dizziness (PPPD) and Quality of Life: A Cross-Sectional Study on 212 Patients

Malin Herwander Steensnæs¹, Mari Kalland Knapstad^2,3, Frederik Kragerud Goplen^1,2, Jan Erik Berge¹,²

¹University of Bergen, Norway; ²Department of Otorhinolaryngology, Haukeland University Hospital, Norway; ³Department of Health and Functioning, Western Norway University of Applied Sciences

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Target audience: Clinicians working with patients with chronic dizziness and researchers in the field.

Objective: To investigate whether Persistent Postural-Perceptual Dizziness (PPPD) was associated with increased burden of dizziness and reduced quality of life, and if so, to determine if this association could be explained by differences in anxiety and/or depression between patients with PPPD and dizzy patients without PPPD.

Study design: Cross-sectional study.

Setting: Outpatient otolaryngology clinic at a tertiary referral center.

Patients: 212 patients aged 18-67 years referred for dizziness were included. 155 (73%) were women. 39 (18,4%) were diagnosed with PPPD.

Main outcome measures: Patients underwent clinical examination and completed the following questionnaires: Dizziness Handicap Inventory (DHI), RAND-12 Health Status Inventory and Hospital Anxiety and Depression Scale (HADS). Scores in DHI and RAND-12 were compared between patients diagnosed with PPPD and patients without PPPD. Associations were tested by linear regression and adjusted for age, gender and HADS.

Results: Patients in the PPPD group had increased burden of dizziness and reduced quality of life (QoL) as shown by a higher DHI score (48.25 vs. 31.38, p<0.001) and reduced RAND-12 physical score (39.5 vs. 44.6, p=0.006). After adjusting for age, gender and HADS, PPPD was associated with a 14.3 (p<0.001) points increase in DHI, and a 3.74 (p=0.022) points reduction in RAND-12 physical score.

Conclusion: Patients with PPPD have a higher burden of dizziness and a lower physical health-related quality of life (HRQoL) compared to other dizzy patients. The difference was evident also after adjusting for anxiety and depression, illustrating how PPPD is a different entity than these common psychiatric conditions

FP1035A Retrospective Analysis of Patients with Vestibular Disorders

Ozlem Gedik Soyuyuce¹, Zeynep Gence Gumus¹, Alper Ozdilek², Nazim Korkut³

¹Acibadem Maslak Hospital Audiology Department; ²Acibadem Mehmet Ali Aydinlar University ENT Department; ³Acibadem Maslak Hospital ENT Department

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Objectives: This study was designed to describe the epidemiological clinical profile of the most common vestibular disorders in adult patients.

Materials and Methods: Data from 1252 (798 women, 454 men) adults with a mean age of 44,52±15,37 (range, 19-92) years were collected from patients who underwent vestibular assessment at a vertigo center in a tertiary hospital over a 1-year period.

Results: Benign paroxysmal positional vertigo (BPPV) was the most common diagnosis in our group of patients (70.04%; n=877), which involved both primary BPPV (n=671), and secondary BPPV that was associated with vestibular migraine (VM; n=128), vestibular neuritis (VN; n=44), Meniere’s Disease (MD; n=30), and labyrinthitis (n=4). In patients with BPPV, the posterior (73.54%; n=645), lateral (19.15%; n=168), anterior (0.68%, n=6), and multiple (6.61%; n=58) semicircular canals were affected. BPPV was unilateral in 72.17% (n=633) and bilateral in 27.82% (n=244). BPPV recurrence over a 1-year period was 6.49% (n=57). VM was the second most common diagnosis (16.77%; n=210) followed by VN (7.66%, n=96), MD (4.39%, n=55), and persistent postural-perceptual dizziness (PPPD; 3.83%, n=48). Our study showed that central vertigo (0.87%, n=11), and labyrinthitis (0.47%, n=6) were less commonly diagnosed. Vestibular paroxysmia was diagnosed in only one patient.

Conclusions: BPPV and VM were the most common vestibular disorders in our study. Clinicians should be aware of the prevalence of the most common vestibular disorders to improve treatment outcomes and differential vestibular function testing is valuable in increasing diagnostic accuracy.

FP1038Benign paroxysmal positional vertigo and vestibular impairment among older adults with dizziness

Ellen Lindell^1,5*, Therese Karlsson^1,2, Lena Kollén³, Mia Johansson^4,6, Caterina Finizia^1,2

¹Department of Otorhinolaryngology, Head and Neck Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; ²Region Västra Götaland, Sahlgrenska University Hospital, Department of Otorhinolaryngology, Head and Neck Surgery, Gothenburg, Sweden; ³Department of Occupational Therapy and Physiotherapy, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; ⁴Region Västra Götaland, Sahlgrenska University Hospital/Sahlgrenska, Department of Oncology, Gothenburg, Sweden; ⁵Region Västra Götaland, Södra Älvsborg Hospital, Department of Otorhinolaryngology, Boras, Sweden; ⁶Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden

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Theme: BPPV among older adults reporting dizziness but not seeking medical care for their symptoms.

Target audience: ENT doctors, geriatrics, physiotherapists

Objective: This study aimed to investigate older adults visiting a geriatric institution for a bone density measurement who reported dizziness on a daily or weekly basis (but who are not seeking care for dizziness), according to BPPV, vestibular function, walking abilities and frequency of falls.

Methods: Patients coming for a bone density measurement answered questions regarding occurrence of dizziness. Patients having dizziness on a daily or weekly basis were considered eligible for the study and invited for investigation at the Ear, Nose and Throat clinic at Södra Älvsborg Hospital, Sweden. The patients answered questions about history of dizziness, medications, and comorbidities. They were also investigated for BPPV, vestibular deficits using the video head impulse test, walking speed, Timed Up and Go test (TUG) and for perception of verticality and horizontality and Romberg test.

Results: A total of 55 patients with dizziness were included. Fifteen (27%) were diagnosed with BPPV. Forty (73%) patients reported falling during the previous year, including 11 with BPPV. Dizziness when turning in bed was more common among patients with BPPV and increased the risk of BPPV eight-fold.

Conclusion: BPPV is common among older adults with dizziness, including among those not seeking medical care. It is important to identify older adults with BPPV and treat the condition since BPPV may contribute to falls. Asking about dizziness when turning in bed can help to distinguish patients with increased risk for BPPV and older adults with dizziness should be investigated for BPPV even when typical history is lacking.

FP1039The Concussion Balance Test (COBALT): Not Just for Youth Athletes Anymore. Norms for Ages up to 90

Shelly Massingale, Amy Alexander, Jamie Pardini

Banner University Sports Medicine and Concussion Specialists

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Purpose: The concussion Balance Test (COBALT) is an eight-condition postural control measure that assesses high-level balance skills initially designed for youth athletes (ages 10-18) participating in contact sports. Conditions 7 (C7) and 8 (C8) are the most challenging, requiring headshake eyes closed (C7) and a visual motion sensitivity (C8), both performed on foam. The purpose of this study was to explore the potential utility of these higher-demand tasks in an active older adult population. A sample of younger to middle-aged adults was used for comparison.

Methods: Subjects (ages 25-90; 49% female) were 85 active and healthy adults. All athletes ages 60+ were participating in the Huntsman Senior World Games (HSWG) athletic events, and athletes in the younger adult sample ranged from triathletes to average active adults exercising 3-4 times per week. COBALT was administered to all athletes, and sway scores and error rates were coded for all athletes able to complete each condition. For purposes of this study, only completion rates by age were examined.

Results: Initial completion rate for athletes ages 25-59 (22 subjects) was 100%; ages 60-69 (33 subjects) was 79%; ages 70-79 (27 subjects) was 63% and 80-89 (4 subjects) was 33%. The primary reason for not being able to complete these conditions was inability to keep up with the pace of the metronome or limited range of cervical spine motion required to move the head the required distance.

Conclusion: Active healthy adults through age 59 appear to be able to complete COBALT conditions C7 and C8, like younger athletes. However, as age increases past 60 years, the ability to complete these challenging conditions decreases. Thus, it will be useful to develop normative data for older age ranges, not only for sway and error rates, but also for completion rate. Clinically, it will be important to understand the impact that non-vestibular factors may have when assessing balance function of older athletes. In addition, study results demonstrate the usefulness of having individual baselines for athletes at all levels against which to compare in the event of an injury.

FP1041Video-oculography ‘HINTS’ in acute vestibular syndrome: a prospective study

Korda Athanasia¹, Michailidou Efterpi¹, Zamaro Ewa¹, Wagner Franca², Caversaccio Marco D.¹, Mantokoudis Georgios¹

¹Department of Otorhinolaryngology, Head and Neck Surgery, Inselspital, University Hospital Bern and University of Bern, Bern, Switzerland; ²University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, University Hospital Bern and University of Bern, Bern, Switzerland.

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Objective: The bedside three steps test known, as ‘HINTS’ (Head Impulse-Nystagmus-Test of Skew), is nowadays a well-established way to discern between peripheral and central causes in patients with acute vestibular syndrome (AVS). Currently, the use of videooculography gives the physicians the possibility to quantify all these eye movements. However, the accuracy of video-oculography (VOG) ‘vHINTS’ is still unknown.

Methods: We performed a prospective study from February 2015 until September 2020 on all patients presenting at the emergency department (ED) with signs of an AVS. All patients underwent a bedside expert ‘bHINTS’ examination and VOG ‘vHINTS’ followed by a delayed MRI, which served as a gold standard for stroke confirmation.

Results: We assessed 46 AVS patients 35 acute unilateral vestibulopathy patients (AUVP) and 11 stroke patients. The overall accuracy of ‘vHINTS’ to detect a stroke was 94% with 100% sensitivity and 88.9% specificity. On the other side, expert ‘bHINTS’ showed a lower accuracy of 88% with 90.9% sensitivity and 85.7% specificity. The agreement between bedside evaluation and videooculography for the head impulse test was good, for the nystagmus test was fair, whereas for the test of skew was almost perfect.

Conclusions: Bedsite ‘HINTS’ performed by experts was accurate for detecting strokes in AVS patients. Video-oculography ‘HINTS’ increased the accuracy of this test with an improvement of its sensitivity and specificity. The quantification of eye movements proves to be a valuable tool for a standardized assement of ‘HINTS’, which heps us to minimize the diagnostic erros.

FP1042Effect of Visual Target Ambiguity on the Semicircular Ocular Reflex

Yumiko O. Kato¹, Fumihiro Mochizuki¹, Koshi Mikami¹, Shuichi Sakamoto², Izumi Koizuka¹

¹Department of Otolaryngology, St. Marianna University School of Medicine; ²Tohoku University Research Institute of Electrical Communication

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To estimate the effect of multi-modal vestibular rehabilitation, we are attempting to find the common scale for accuracy of location perception among modalities. We evaluated the effect on Semicircular Ocular Reflex (ScOR) gain by the visual stimuli with various ambiguity.

14 healthy adults participated in the present study. Horizontal eye movements were recorded by video-oculography under three conditions. In the earth fixed (EF) condition, the absolute position of the visual target was fixed. In the head fixed (HF) condition, the visual target was rotated in same direction to head rotation. In the pursuit (P) condition, the visual target was rotated sinusoidally without head rotation. We used six-patterns visual targets in three levels of blurriness and two levels of brightness. As the blurriness level, we set the circle with clear edge at one-degree diameter, the blur circle about 20 degrees diameter, and about 40 degrees diameter. The blurriness was made with Gaussian filter. The visual stimuli were projected on cylindrical screen (OKN screen) around the subjects. The chair the subjects were sitting on was rotated sinusoidally in the yaw-axis at 0.32Hz at an amplitude of 20 degrees. For the control, we observed the ScOR in complete darkness at the same frequency and amplitude. The Visual ScOR (VScOR) gain under the EF and HF conditions and the pursuit gain under the P condition were analyzed by the Steel-Dwass test, in which the significant level was 0.05.

Under the EF condition, visual stimuli enhanced ScOR gain. The gain enhancement was significantly different among both brightness levels and blurriness levels. Brighter and clearer stimulus tended to cause larger effect on ScOR. Under P condition, also the pursuit gain was significantly different among both brightness levels and blurriness levels. Under the HF condition, visual stimuli suppressed ScOR gain. The VScOR gain with brighter stimulus tended to be smaller. No significant difference in VScOR gain among blurriness levels, was indicating that even ambiguous position information could suppress eye movement. Under all conditions, with brighter target, there was no difference among blurriness levels, but with dark target, blurriness levels could affect the eye movement. These suggested that the effect on ScOR may be possible to estimate the amount of information in location perception throughout plural modalities. Ambiguous stimuli caused less effect on ScOR. This suggested that the effect on ScOR may indicate accuracy of perceived position.

This work is supported by JSPS KAKENHI Grant Number JP19K12088.

FP1043Feasibility of VestAid: A Tablet-based Technology for Objective Exercise Monitoring in Vestibular Rehabilitation

Brooke N. Klatt¹, Pedram Hovareshti², Lisa S. Holt², Pamela M. Dunlap¹, C Zalkin², D Tolani², Susan L. Whitney^1,3

¹Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, USA; ²Intelligent Automation, A BlueHalo Company., Rockville, MD, USA; ³Department of Otolaryngology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA

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A low-cost home-exercise system called VestAid has been developed to assist participants in the performance of vestibulo-ocular reflex (VOR x1) gaze stabilization exercises outside of clinic visits. VestAid includes a tablet-based app for the participant and a web-based portal for the physical therapist that provides exercise accuracy and performance data. VestAid utilizes a computer tablet camera to assess gaze stabilization accuracy and head motion performance, records participant-imputed symptom data before and after each exercise, and provides clinicians with near real-time objective (head speed compliance, gaze stabilization accuracy) and subjective (symptoms and perceived difficulty) metrics of exercise performance.

The feasibility and acceptability of VestAid was assessed in a study of ten participants (mean age = 45, SD = 19, 6 females) with various vestibular diagnoses. All participants completed twelve 30-second horizontal VOR x1 exercises in a seated position. The exercises differed by variations in the background color, pattern, and movement. One of the exercises was repeated to assess the test-retest reliability of gaze stability accuracy and head motion compliance during the exercise. After completing an exercise, each participant rated the perceived difficulty of the exercise using a 0 to 10 scale (0 = extremely easy and 10 = extremely difficult). Participants were asked about their experience and completed usability surveys using eight qualitative open-ended questions and ten statements to which they indicated their agreement (strongly disagree, disagree, neutral, agree, or strongly agree).

Participants with vestibular disorders were able to complete the trials without adverse events. The responses from the usability survey demonstrate acceptability of the VestAid device evident by the favorable feedback provided. Nine out of ten participants agreed or strongly agreed that it was easy to rate the difficulty of exercises. The study team categorized the twelve VOR x1 exercises as either “easy” or “difficult” (six of each). The mean rating of the “easy” exercises across participants was 2.7/10, SD = 1.9. The mean rating for the “difficult” exercises across participants was 4.8/10, SD = 2.1. The consistency of the mean ratings of the participants with the exercise classifications (“easy” and “difficult”) by physical therapists suggests that the VestAid device has clinical utility. Gaze stabilization accuracy output had excellent reliability (r=0.98) and head motion compliance output had good reliability (r=0.82).

VestAid provides an objective way to monitor gaze stabilization exercise performance outside of the clinic and has the potential to motivate participants to complete their home exercise program.

FP1045Analysis of 25-OH Vitamin D in Persistent Benign Paroxysmal Positional Vertigo, an observational study

Alberto Codina-Aroca¹, Darío Agudelo², Santiago Díez², Núria Mir²

¹Hospital Clinic de Barcelona (Barcelona, Spain); ²Fundació Hospital de l’Esperit Sant (Santa Coloma de Gramenet, Spain)

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Benign Paroxysmal Positional Vertigo (BPPV) is the most frequent type of vertigo and of special interest are those which don’t improve after several consecutive repositioning maneuvers. We included patients diagnosed with Benign Paroxysmal Positional Vertigo (BPPV) who didn’t improve after three canalith repositioning maneuvers (CRM) and performed blood tests which included 25-OH Vitamin D, Calcium, and Parathyrin (PTH). We found that all the patients that require a Canalith repositioning maneuver (CRM) in three consecutive weeks have low levels of vitamin D. We also started treatment to these patients with an improvement after the correction. Vitamin D deficit could cause a hyperlability state in otoconiae that could be responsible for a persistent BPPV that doesn’t improve with repositioning maneuvers.

FP1046Frequencies of Vestibular Syndromes, diagnosis and change of diagnosis rates in patients with Dizziness presenting to a tertiary Emergency Department

Georgios Mantokoudis¹, Athanasia Korda¹, Lukas Comolli¹, Ewa Zamaro¹, Franca Wagner², Thomas Sauter³, Marco D. Caversaccio¹

¹Department of Otorhinolaryngology, Head and Neck Surgery, Inselspital, University Hospital Bern and University of Bern, Bern, Switzerland; ²Department of Diagnostic and Interventional Neuroradiology, Inselspital, University Hospital Bern and University of Bern, Bern, Switzerland; ³Department of Emergency Medicine, Inselspital, University Hospital Bern and University of Bern, Bern, Switzerland.

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Background: Our aim was to determine the frequency of vestibular syndromes, frequencies of diagnoses, diagnosis change rates, and resources used in patients with dizziness in a tertiary emergency department (ED) as well as in the follow-up examination.

Methods: In this retrospective longitudinal study, we included all adult patients presenting with dizziness in the ED from 07/2015 until 08/2020. Based on medical history we determined the type of vestibular syndrome. We collected data about baseline demographics, medical history, clinical findings, resources used, and diagnosis from the initial ED report and from the follow-up report if available.

Results: Overall, we included 1535 patients with dizziness. 429 of these 1535 patients (27,9%) had an acute vestibular syndrome (AVS), 35,0% an episodic vestibular syndrome (EVS), 4,8% a chronic vestibular syndrome (CVS), and 23,2% no vestibular syndrome. The three most frequent diagnosis were Stroke / minor Stroke (10.1%), BPPV (benign paroxysmal positional vertigo) (9,7%) and vestibular neuritis (9,6%). In patients with an AVS (30,3%) had a stroke. In 45% the cause of the dizziness remained unknown und 31.4% received a false diagnosis. In cases with a follow-up available, 58.2% of the initially unknown diagnoses received a diagnosis in the follow-up. In 29 cases (4,4%) a dangerous diagnose was missed at the ED. Overall, 69.9% of all 1535 dizzy patients received neuroimaging (MRI 58,2%, CT 11,6%) at the ED visit.

Conclusions: One third of dizzy patients in the ED present with AVS with a high prevelance of vestibular strokes. Episodic vertigo (EVS) was equally frequent, however, the rate of undiagnosed patients was high due to a symptom free interval at the time of ED presentation. The proportion of patients receiving neuroimanging was very high, however, almost half of them still remained without diagnosis and among those diagnosed were often misclassified. Many unclear cases of vertigo could be diagnostically clarified after a follow-up visit.

FP1052Clinical Characteristics in Unilateral Vestibular Atelectasis

Morgane Marc, Charlotte Hautefort, Jean Pierre Guichard, Philippe Herman, Emmanuel Houdart, Michel Toupet, Michael Eliezer

APHP, Université de Paris

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Introduction: Unilateral vestibular atelectasis (UVA), an entity first described by Merchant and Schuknecht in 1988, has rarely been reported in vivo as of yet. We specify here the clinical characteristics of 22 patients diagnosed with UVA.

Materials and methods: Patients with a radiological diagnosis of UVA who underwent delayed inner ear MRI were included between April 2017 and January 2020. Full clinical testing including ocular infrared video-oculography, oVEMPs, cVEMPs, vHIT, bithermal caloric testing and auditory testing was performed.

Results: There were 13 men and 9 women, of mean age 58.6 ± 13.7 years. Onset was more frequently sudden (73%) than insidious (27%) though both clinical presentations were reported, and positional vertigo was described in 41% of cases. There were only two (9%) patients reporting Tullio’s phenomenon. Vestibular testing showed that in 90% of cases, there was utricular dysfunction on oVEMP, while in 77% of cases, saccular function was preserved on cVEMP. vHIT showed high-velocity canal function impairment in all 22 patients: 8 patients (36%) had one impaired canal, 5 (23%) had two and 9 (41%) had all three canals affected. Caloric tests found complete unilateral areflexia, in 65% of tested cases, and partial deficiency in 35% of cases. Nine patients (40%) displayed asymmetrical hearing.

Conclusion: We described in this study the various clinical presentations of a disease rarely reported in vivo, UVA. Initial clinical presentation can appear similar to an acute vestibular deficit, a recurrent positional vertigo, or fluctuating dizziness.

FP1053Electrophysiological and Inner Ear MRI findings in Patients with Bilateral Vestibulopathy

Michael Eliezer¹, Charlotte Hautefort², Christian Van Nechel³, Ulla Duquesne³, Jean Pierre Guichard¹, Philippe Herman², Romain Kania², Emmanuel Houdart¹, Arnaud Attyé⁴, Michel Toupet⁵

¹Department of Neuroradiology and MR Unit, Lariboisière, Université de Paris. ²Department of Head and Neck Surgery, Lariboisière, Université de Paris. ³Clinique Des Vertiges, Brussel, Belgique. ⁴Department of Neuroradiology and MRI, SFR RMN Neurosciences, Grenoble Alpes University Hospital, Grenoble, France. ⁵Centre d’Explorations Fonctionnelles Otoneurologiques, Paris, France

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Purpose: Bilateral vestibulopathy (BV) is an uncommon disorder and the etiology remained idiopathic in most cases. Delayed 3D-FLAIR sequences have provided new insights into various inner ear diseases, allowing the evaluation of the endolymphatic space and the permeability of the blood-labyrinthine barrier (BLB). The aim of this study was to assess both the morphology of the endolymphatic space and the permeability of the BLB in patients with BV as evaluated by delayed 3D-FLAIR sequences.

Methods: In this retrospective study, we performed 3D-FLAIR sequences 4 h after administering contrast media to 42 patients with BV. Two radiologists independently evaluated the morphology of the endolymphatic space (either vestibular atelectasis or endolymphatic hydrops) and the permeability of the BLB.

Results: Morphologic anomalies of the endolymphatic space and vestibular blood-labyrinthine barrier impairment were observed in 59.6% of patients with BV. Bilateral vestibular atelectasis (VA) was found in 21 patients (50%), involving only the utricle and all three ampullas while the saccule was always observed with no sign of collapse: idiopathic BV (n = 19), aminoglycoside administration (n = 1) and few days following abdominal surgery (n = 1). One patient had bilateral vestibular malformation. BLB impairment was observed in five patients (11.9%): paraneoplastic (n = 1), lymphoma (n = 1), autoimmune (n = 1), and vestibular “neuritis” (n = 2). Seventeen patients (40.4%) had normal MRI with no endolymphatic space anomaly or BLB impairment.

Conclusion: Patients with BV presented with morphologic anomalies of the endolymphatic space or BLB impairment in 59.6% of patients.

FP1055Delayed onset of vertigo/dizziness in patients with posttraumatic perilymph fistula

Kazuhiko Kubo, Yuki Naritomi

Department of Otorhinolaryngology & Head and Neck Surgery, Chidoribashi General Hospital

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Background: Perilymph fistula is a rupture of two windows of inner ear and is characterized by Meniere’s disease-like symptoms including vertigo/dizziness, hearing loss, tinnitus and ear fullness. Although it is well known that traffic accidents induce perilymph fistula, the onset of vertigo/dizziness is not necessarily the same as the day of traffic injury and then this mismatch often gets into trouble between those patients and insurance providers. Since there are posttraumatic patients with delayed onset of vertigo/dizziness in actuality, it is important to reveal characteristics of patients with delayed onset of vertigo/dizziness after traffic accident and to discuss the mechanism of this mismatch.

Methods: Retrospective electric records-based study was designed. The posttraumatic subjects with delayed onset of vertigo/dizziness were recruited from the lists of patients who underwent the surgical closure of perilymph fistula at the department of otorhinolaryngology & Head and Neck Surgery of Kyushu University Hospital from 2007 to 2018. We collected age, gender, symptoms, the day of onset of vertigo/dizziness, vestibular examination, audiogram, site of fistula, outcome etc. for descriptive statistics. This study was approved by our institutional ethics committee.

Results: Twelve patients were recruited and a half of patients complained vertigo/dizziness later. There were no association between the persistent vertigo/dizziness and many parameters including age, gender, symptoms, nystagmus, fistula phenomenon, hearing level and caloric response. The patients with persistent vertigo/dizziness tended to have abnormal vestibular evoked myogenic potential.

Conclusions: The onset of vertigo/dizziness after traffic accident was not related to medical parameters. We should know that posttraumatic onset of vertigo/dizziness delays not infrequently.

FP1056Characteristics of patients with vertigo/dizziness in emergency facility having an MRI device

Yuki Naritomi, Kazuhiko Kubo

¹Department of Otorhinolaryngology & Head and Neck Surgery, Chidoribashi General Hospital

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Background: Vertigo/dizziness are one of most common causes for calling the emergency services. The patients with emergent vertigo/dizziness are usually referred to emergency hospital. Up to now, many reports demonstrated the characteristics of emergent care of patients with vertigo/dizziness in emergent hospital. However, those have diversity among reports because there are many differences in the level of medical services and insurances among countries. The specificity of emergent care for patients with vertigo/dizziness is easy to take MRI imaging in most Japanese emergent hospitals. The diffusion-weighted MRI images have an ability of early detection of acute brain infarction. The aim of this study is to reveal characteristics of patients with vertigo/dizziness in in emergency facility having an MRI device.

Methods: Retrospective electric records-based study was designed. The subjects with vertigo/dizziness were recruited from the lists of patients whom an ambulance car took to the emergency unit at Chidoribashi General Hospital in the second half of 2019. We collected age, gender, diagnosis, MRI images, admission, duration of admission, outcome etc. for descriptive statistics. This study was approved by our institutional ethics committee.

Results: Many patients with acute vestibular syndrome were referred to our hospital using an ambulance car. Many of them underwent MRI scan to exclude acute brain infarction just after vital check, an examination of blood and electrocardiogram. As a result, many patients were diagnosed as peripheral vertigo and selected whether to be admitted to hospital.

Conclusions: Several methods for assessment of cerebral infarction without MRI, such as HINTS and ABCD2 score, were developed to evaluate whether the patients with vertigo/dizziness have an infarction in the brain or not. Early MRI imaging may bring a secure feeling to the patients with vertigo/dizziness and facilitate the following process of treatment.

FP1063The Impact of Muscle Mass in the Body Balance of Morbidly Obese

Camila Brock, João Grossi, Bruno Hochhegger Camila Martins Brock¹, João Vicente Machado Grossi², Bruno Hochhegger³

Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Rio Grande do Sul, Brazil

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Abstract:

Background: The decrease of muscle mass in obesity is linked to body instability. However, the pathway of this correlation is not fully understood.

Objective: To study the relationship between body balance and muscle mass in morbidly obese patients.

Methods: 40 subjects, 6 men, (average age 38,03 ± 10,63) enrolled the study. 20 obese with body mass index ³ 35 kg/m2 and 20 non morbidly obese were submitted to body balance assessment with portable posturography equipment (BAP - Balance Angular Posturography). The stability limits were measured and the Sway per minute (Sway/m) obtained in the X and Y axis under 4 different conditions, combining opened eyes, closed eyes, firm platform and unstable platform. Data were related to the measurement of cervical, waist and hip circumference in centimeters (cm) and to the percentage of fat and muscle mass of the lower limbs and trunk by bioimpedanciometry (Beurer).

Results: The data were analysed by SPSS using the t-test. The Sway/m on the X axis in the condition opened eyes and firm platform was higher in the morbidly obese group (p = 0,006). In the condition closed eyes and unstable platform, the value of Sway/m on the X axis (p = 0,006) and on the Y axis (p = 0,014) was also higher in the obese group. There was significant difference in cervical circumference (p = 0,007), waist (p = 0,001), hip (p < 0,001), percentage of muscle mass per lower limb (left leg and right leg p < 0,001) and trunk (p = < 0,001). The oscillatory area of the stability limits did not show statistical result (p = 0,483).

Conclusion: Body balance initially prioritizes muscle activation around the ankle joint. When challenged by the lack of visual fixation and/or the proprioception, the perception of the proximal body is recruited to contain the tendency to increase instability. The decrease in the percentage of muscle mass in morbidly obese individuals alters the body balance, reducing the capacity for postural control.

FP1064The DizzyQuest: an app-based diary for vestibular disorders

E.C. Martin¹, C. Leue², P. Delespaul², F. Peeters³, A. Erdkamp⁴, S.C.F. van de Weijer⁴, L. de Joode¹, D. Sitters¹, R. Verkaik¹, H. Blom⁵, T. Bruintjes⁶, A. Zwergal⁷, E. Grill⁸, N. Guinand⁹, M.R. van de Berg¹, J.J.A. Stultiens¹, H. Kingma^1,10, R. van de Berg^1,10

¹Division of Balance Disorders, Department of Otorhinolaryngology and Head and Neck Surgery, Maastricht University Medical Center, Maastricht, The Netherlands; ²Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands; ³Department of Clinical Psychological Science, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands; ⁴Department of Psychiatry and Psychology, Maastricht University Medical Center, Maastricht, The Netherlands; ⁵Department of Otolaryngology - Head and Neck Surgery, HagaZiekenhuis, the Hague, The Netherlands; ⁶Apeldoorns duizeligheidscentrum, Gelre ziekenhuizen, Apeldoorn, The Netherlands; ⁷Department of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany; ⁸Department of Medical Informatics, Ludwig-Maximilians-University of Munich, Munich, Germany; ⁹Service of Otorhinolaryngology - Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland; ¹⁰Faculty of Physics, Tomsk State Research University, Tomsk, Russia

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Background: Currently used questionnaires for vestibular disorders are mainly retrospective, inducing recall bias and decreasing ecological validity. To overcome these problems, the DIZZYNET network recently introduced an app-based diary for vestibular disorders: The DizzyQuest. It investigates vestibular symptoms in their psychosocial context within the same person, using multiple daily questionnaires. Hereby, fluctuating symptoms (like in Meniere’s disease) can be captured more reliably. Study objectives were to investigate: 1) response rates; 2) convergent validity; 3) the agreement between reported vertigo attacks in the evening- and attack-questionnaire; and 4) the relation between self-reported hearing symptoms and objective hearing thresholds.

Methods: Seventy-nine patients were included to use the DizzyQuest for one month. For each research question, a different subset of this eighty patients was used for analysis, based on the inclusion criteria. In the first week, the questionnaires were administered at different frequencies: morning- (1x), day- (10x), evening- (1x), attack-questionnaire (to be filled in directly after a vertigo attack). In week two to four, the evening- and attack-questionnaire remained to be filled in at the same frequency. Response rates were measured by dividing the amount of completed questionnaires by the amount of administered questionnaires. Convergent validity was investigated by comparing twelve questions of the DizzyQuest with ten corresponding questions from the Dizziness Handicap Inventory, Hospital Anxiety and Depression Scale and EuroQol-5D-5L. Vertigo attack symptoms of the evening-questionnaire were compared to the symptoms that were reported in the attack-questionnaire. Self-reported hearing symptoms were compared to hearing thresholds obtained with an iPad-based hearing test, that was directly administered after completing the DizzyQuest evening-questionnaire.

Preliminary results: Average response rates varied from around 70% (day-questionnaire) to >90% (evening-questionnaire). Regarding convergent validity, significant correlations (4 strong, 4 moderate, 1 weak) were found in 9 out of 10 investigated combinations of questions. A discrepancy was found between reported symptoms in the evening-questionnaire versus the attack-questionnaire regarding nature and frequency (749 versus 199 reported vertigo attacks respectively) of vertigo attacks. Self-reported hearing symptoms significantly correlated with hearing thresholds on an intrapersonal level, but not on an interpersonal level.

Conclusion: The DizzyQuest seems a promising tool for investigating vestibular symptoms and their psychosocial context, with low recall bias and high ecological validity. It shows desired response rates, an acceptable convergent validity and self-reported hearing symptoms correlate well on an individual level with objective measures. To investigate vertigo-attacks, the combination of an evening-questionnaire and attack-questionnaire seems complementary to capture vertigo attacks reliably, but needs further investigation.

FP1066Preliminary Study on the Effectiveness of the Geneva Balance Test (GBT) on Children with Bilateral Vestibulopathy

Emile G. Monin, Céline Bahim, Maurizio Ranieri, Jean-François Cugnot, Nils Guinand, Angélica Pérez Fornos, & Hélène Cao Van

Hôpitaux Universitaires de Genève

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Background: Vestibular deficits are considered to be rare in children, but the lack of systematic screening leads to underdiagnosis. The few studies made on this topic have demonstrated that chronic vestibular dysfunction impacts psychomotor development of children. Early screening of these children is needed to allow optimal follow-up, ensuring better global development. To this purpose, we have developed a screening test to quantify the balance capacity of children over a broad age range, the Geneva Balance Test (GBT).

Methods: The aim of the study was to determine the possibility of quantifying balance deficits in children with bilateral vestibulopathy (BV) using the GBT. We conducted an observational prospective study in a population of 11 children with BV. Two age-matched control groups were included in the study, composed of (1) 15 healthy children without vestibular nor auditory disorder (HS) and (2) 11 pediatric cochlear implant recipients (CI) without vestibular disorders (since sensorineural deafness is frequent in children with BV). Results of the three populations have been compared in 3 age groups (3-5 years, 6-9 years, =10 years), and with results of the Bruininks-Oseretsky Test of Motor Proficiency Ed. 2 (BOT-2).

Results: Statistical analyses demonstrated significant differences in the GBT scores between 3-5 and =10 years children with BV and both control populations. A similar tendency was observed in the 6-9 years group, but results did not reach significance for this smaller group. Children in the 3-5 years CI group showed intermediate balance capacities (worse than HS but better than BV), that normalize in the 6-9 years group. All the results of the GBT were significantly correlated with BOT-2 results, but the GBT was better tolerated in all populations.

Conclusions: In this small study, the GBT allowed to quantify balance deficits in children with BV. These results were comparable with the results of the BOT-2, which has been validated by multiple studies. However, the BOT-2 test is not validated for children <4,5 years, and results quickly saturate reaching maximal values already at 6-9 years. The GBT showed potential to be a useful tool to monitor the development of balance capacities with age and as such could be used in the follow-up of children with BV. Interestingly, we observed a significant difference in balance capacities in very young CI children which normalized by 6-9 years, potentially due to hearing rehabilitation with CI. A study with a larger population is necessary to confirm these results.

FP1068Altered hippocampal functional connectivity in persistentpostural perceptual dizziness

He Zhao¹, Xiaozhen Li², Zheng-guang Chen², Li-qun Zhong¹

¹Department of Neurology, Dongzhimen Hospital, Beijing University of Chinese Medicine,5 Hai Yun Cang Hutong, Beijing, 100700, PR China; ²Department of Radiology, Dongzhimen Hospital, Beijing University of Chinese Medicine, 5 Hai Yun Cang Hutong, Beijing, 100700, PR China

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Background: Persistent postural perceptual dizziness (PPPD) is a vestibular disorder of persistent dizziness and unsteadiness. Many studies demonstrate the importance of vestibular–hippocampal interactions for hippocampal function and indicated the hippocampus might be important for compensation of vestibular function. Resting-state functional magnetic resonance imaging (rs-fMRI) has been widely used in brain function studies. However, hippocampal functional connectivity using rs-fMRI in patients with PPPD has not been reported.

Methods: A total of 30 subjects, including 14 patients with PPPD and 16 healthy controls underwent rs-fMRI on a 3T MR scanner. After the imaging preprocessing, seed-based functional connectivity analysis was performed on the bilateral hippocampus using AFNI software. The independent sample t test was used to compare the differences between two groups of hippocampal functional connectivity with age and sex as covariates.

Results: PPPD showed significantly increased hippocampal functional connectivity in the right lingual gyrus, left cuneus, right precuneus and right cerebellum adjusted for age and sex. We also found decreased connectivity in the left inferior parietal lobule, left medial frontal gyrus, left putamen and left precentral gyrus.

Conclusion: The hippocampal functional activities in PPPD patients were altered, potentially leading to abnormal integration of visual and vestibular information. Patients with PPPD showed the regions with increased connectivity linking visual spatial processing, while reduced connectivity among the areas involved in multisensory vestibular processing and body movement. Hippocampal functional connectivity patterns may become an imaging biomarker of PPPD and helpful for early diagnosis.

Keywords: Persistent postural-perceptual dizziness (PPPD); Resting state functional magnetic resonance imaging (rs-fMRI); Functional connectivity; Hippocampus

Key points: *The hippocampus may be important for compensation of vestibular function in patients with PPPD.

*This study investigated the hippocampal functional connectivity changes using rs-fMRI in PPPD.

*Hippocampal functional connectivity patterns may become an imaging biomarker of PPPD and helpful for early diagnosis.

Target Audience: Neurologist and others

FP1069Discrepancy between the video head impulse and bithermal caloric tests; prevalence, etiology and localization in dizzy patients

Ju-Young Lee, MD¹, Eunjin Kwon, MD², Hyo-Jung Kim, PhD³, Jeong-Yoon Choi, MD, PhD⁴, Hui Jong Oh, MD, PhD⁵, Ja-Won Koo, MD, PhD⁶, Ji-Soo Kim, MD, PhD⁴

¹Department of Neurology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Republic of Korea; ²Department of Neurology, Chungnam National University Hospital, Daejeon, South Korea; ³Research Administration Team, Seoul National University Bundang Hospital, Seongnam, South Korea; ⁴Dizziness center, Clinical Neuroscience Center, and Departmemt of Neurology, Seoul National University Bundang Hospital, Seongnam, South Korea; ⁵The MTV (Migraine, Tinnitus, and Vertigo) Clinic, Oh Neurology Center, Daegu, South Korea; ⁶Dizziness center, Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, South Korea

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Objective: This study investigated the prevalence, pattern, lesion location, and etiology of discrepancy in the results of caloric test and video head impulse test (vHIT) in patients with vestibular symptoms from diverse etiologies and disease duration.

Methods: We reviewed the results of vHIT and caloric test in 893 consecutive patients who had taken both tests within 10 days from March 2016 to May 2018.

Results: The discrepancy between the tests was found in 162 (18.1%) patients. Among them, 123 (75.9%) revealed abnormal caloric tests with normal vHIT (abnormal caloric test group). In this group, most patients (118/123) had unilateral canal paresis and 5 had bilateral canal paresis. Regarding lesion location, 105 (85.4%) patients had etiologies belonged to the peripheral pathology, such as Meniere’s disease (62/105, 59%) and vestibular neuritis/labyrinthitis (29/105, 27.6%). 18 (14.6%) showed central pathology in diverse etiologies. Meanwhile, abnormal vHIT and normal caloric response (abnormal vHIT group) was observed in 39 (24.1%), in which patients with bilaterally positive vHIT was observed in 18, unilaterally positive in 19, and hyperactive in 2. These patients showed a similar distribution of the central (n=19) and peripheral (n=20) lesions. Vestibular neuritis/labyrinthitis (7/20, 35%) and Meniere’s disease (7/20, 35%) were evenly included in the peripheral lesions, while the etiology of the central lesions varied.

Conclusion: The discrepancy between vHIT and bithermal caloric tests is not uncommon. The abnormal caloric test groups mostly had peripheral disease while the abnormal vHIT group had a substantial chance for central lesions.

FP1070Therapeutic Efficacy of Botulinum Toxin Type A in Patients with Vestibular Migraine: Changes in Resting-State Functional Connectivity in a Longitudinal fMRI Study

Sun-Young Oh, MD, PhD^1,2, Jin-Ju Kang, MD^1,2, Sohui Kim³, Jong-Min Lee, PhD⁴, Ji Soo Kim, MD, PhD^5,6; Marianne Dieterich, MD, PhD^7-9

¹Department of Neurology, Jeonbuk National University Hospital & School of Medicine, Jeonju, Korea; ²Research Institute of Clinical Medicine of Jeonbuk National University-Jeonbuk National University Hospital, Jeonju, Korea; ³Department of Electronic Engineering, Hanyang University, Seoul, Korea; ⁴Department of Biomedical Engineering, Hanyang University, Seoul, Korea; ⁵Department of Neurology, Seoul National University College of Medicine, Seoul, Korea; ⁶Department of Neurology, Dizziness Center, Clinical Neuroscience Center, Seoul National University Bundang Hospital, Seongnam, Korea; ⁷Department of Neurology, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany; ⁸German Center for Vertigo and Balance Disorders, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany; ⁹Munich Cluster for Systems Neurology (SyNergy), Munich, Germany a: These three authors contributed equally to this work as first authors. b: These two authors contributed equally to this work as corresponding authors

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Background: Vestibular migraine (VM) has been recognized as a distinct clinical entity with recently published diagnostic criteria. Although migraine prophylactic medications can improve headache profiles and dizziness symptoms, treatment trials that focus on VM are scarce. Botulinum toxin type A (BTX-A) has been approved for prophylactic treatment of chronic and episodic migraine; however, its efficacy for migraine-related dizziness or VM has not been validated. The purpose of this study was to investigate the efficacy of BTX-A in prophylactic treatment of VM and to determine whether this treatment modulates intrinsic functional brain network connectivity.

Methods: Twenty patients (mean age 45.4 years, range 20–69 years) who satisfied the Bárány Society and International Headache Society diagnostic criteria for VM and who were refractory to conventional prophylactic therapies for more than five months had BTX-A injection and resting-state fMRI (rs-fMRI) before and 2 months after the injection. We measured the changes in the frequency of vertigo and migraine attacks, symptomatic functional disability scores, and neuropsychiatric inventories before and after the treatments.

Results: After BTX-A injection, the mean monthly frequencies of migraine and vertigo episodes decreased significantly compared to baseline (p<0.01, Wilcoxon signed rank test). The headache impact, as measured by the Headache Impact Test-6 score and the Migraine Disability Assessment, was improved (p<0.001). The vertigo parameters, measured by the Dizziness Handicap Inventory and the Vertigo Symptom Scale, showed an improvement (p<0.001), as did the anxiety and depression scores (p<0.001) 2 months after BTX-A treatment. The low-frequency fluctuation analysis of the rs-fMRI data found significant changes in functional connectivity of the right superior temporal gyrus (STG). Adoption of the right STG cluster as the seed region, increased functional connectivity with the left post-central gyrus, right supramarginal gyrus, and right middle temporal gyrus was seen after BTX-A treatment.

Conclusion: This prospective study shows that BTX-A treatment is effective at ameliorating migraine headache and vertigo symptoms in VM patients who were refractory to conventional medical therapies. Along with symptomatic improvements, changes in the functional connectivity within the multisensory vestibular and pain networks in the right temporal regions suggest that abnormal brain activity leads to dysmodulation of multimodal sensory integration and abnormal cortical processing of the vestibular and pain signals in VM patients.

FP1071Fatigability Presenting with Video-oculographic findings in Myasthenia gravis

Jin-Ju Kang, MD¹, Eunsu Lee, MD¹, Sun-Young Oh, MD, PhD^1,2

¹Department of Neurology, Jeonbuk National University Hospital & School of Medicine, Jeonju, Korea; ²Research Institute of Clinical Medicine of Jeonbuk National University-Jeonbuk National University Hospital, Jeonju, Korea

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Background: Myasthenia gravis (MG) is an autoimmune disease caused by abnormal transmission of neuromuscular junction, and it is characterized by diplopia, ptosis, ophthalmoplegia and muscle weakness. And it features fatigability that means fluctuating symptoms and worsen due to muscle movement. In the early stage, the patients complain of eye symptoms, 46% of patients are not adequately diagnosed during the first year of illness. Ancillary test such as antibody assays, edrophonium test, and electrophysiologic test including repetitive nerve stimulation test, and single fiber EMG. However, gold standard of diagnosis is not defined until now. We therefore analyzed eye movement findings in myasthenia gravis using video-oculography.

Methods: We performed a total of 46 MG patients and 24 controls. All MG patients complained of ocular symptoms such as ptosis and diplopia. Patients who were positive for one or more of the repetitive stimulation test, edrophonium test, and acetylcholine receptor antibody test were selected. Video-oculography was performed the range of 20 degree was measured for 6 minutes to measure rapid eye movement, and 20 degree range for 6 minutes to measure slow eye movement.

Results: 50 repetitive saccades and smooth pursuit movements of both eyes (more and less affected eye) tested in both vertical and horizontal planes allowed for effective differentiation between MG patients and healthy subjects. Repetitive vertical saccadic eye movements yielded the best differentiation between patients with MG and controls with a sensitivity of 73% and a specificity of 92% when using a gain decrement of 9.3% as cutoff.

Conclusions: Eye movements are caused by using different rates of twitch fiber and tonic fiber. If tonic fibers are mainly involved in myasthenia gravis, smooth pursuit movement can be impaired. Therefore, quantitative analysis of the slow eye movement as well as rapid eye movement in patient with MG who is showed fatigability, can be helpful in early diagnosis and understanding pathology of MG.

FP1077The Factors of the Compliance to the Customized Vestibular Exercise

Eun-Ju Jeon, Hyun Jin Lee

The Catholic University of Korea

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Vestibular rehabilitation is one of the essential parts in the treatment of dizziness. Customized vestibular exercise is considered superior to generic exercise. However, it is hard to approach since it varies on the individual patient’s functional status and therapist’s knowledge and experience.

Since the customized vestibular exercise (CVE) was initiated in this clinic in April, 2017, 89 patients were undergone the customized exercise treatment for control of dizziness and unsteadiness. The formal CVE schedule was consisted of 4 sessions of 30 minute of supervised exercise at weekly base. After supervised exercise for 30 minutes in the clinic, home exercise 3 times/day was prescribed. If multiple session treatments were not possible due to personal circumstances, such as a remote location, work-related reasons, or cost burden, single session treatment was performed.

The prediction of non-adherence to a CVE treatment, prior to initiation of the treatment, would allow optimization of health resources. We tried to find what factors determine the compliance to the CVE.

62 patients agreed to proceed with formal 4 sessions of CVE. Vestibular neuritis was the most common etiology. Unilateral vestibular hypofunction, acoustic neuroma, BPPV, Meniere’s disease, etc. followed as common etiology for CVE treatment. Three patients abandoned the treatment at the beginning. One patient discontinued the treatment after one session. 32 patients (51.6%) completed the 4 sessions of CVE. In terms of disease category, VM and labyrinthits showed 100% of adherence.

The patients were divided into 2 groups: Adherence group (group A) was defined as who completed 3 to 4 sessions. Non-adherence group (group NA) was who performed 0~2 sessions of CVE. Group A showed less fall number (2.4±2.8) at sensory organization test (SOT) than group NA (4.5±4.1), and it was statistically significant (P=0.026). Age, sex, dizziness related questionnaire score, VFT parameters except for fall number at SOT were not significantly different between the two groups. The patients most likely to abandon a CVE program are who showed multiple falls (>4.5) at SOT. It seems that the subjective perception of instability limitations does not affect motivation for vestibular rehabilitation. It is necessary to pay special attention to the patients with multiple falls, and have regular follow-up appointments to encourage adherence.

FP1078Variability and efficacy of prophylactic treatment in patients with Probable and Definite Menière’s Disease

Iveta Csekesova¹, Lukas Varga², Agnesa Nagy Potasch²

¹Center for Vestibular Disorders, Komarno Agel Hospital, Komarno, Slovakia; ²Department of Otorhinolaryngology – Head and Neck Surgery, Faculty of Medicine and University Hospital, Comenius University, Bratislava, Slovakia; ³Center for Vestibular Disorders, Komarno Agel Hospital, Komarno, Slovakia

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Introduction: Menière’s Disease is a chronic inner ear disorder, common cause of hearing and balance impairment, which may have long-term negative impact on patient’s quality of life. At the present time, there is no causal cure, but there are always ways to manage the condition and help control the symptoms. The aim of our study was to investigate and define effective prophylactic treatment in patients with Probable or Definite Menière’s Disease, particularly focused on vertigo and achieving at least 6 months of attack-free interval or only sporadic seizures.

Methods: Single-center retrospective study on 237 patients with Probable or Definite Menière’s Disease who were diagnosed and treated from 2019 to 2020. Prophylactic treatment usually started with single administered drug containing Betahistine. Hydrochlorothiazide was used as an option in case of reported allergy or intolerance. Sufficiency of disease control was assessed on the regular visits after the 1st, 3rd, 6th and 12th months of treatment. It was based on patient’s self-reported data with no or only sporadic /1-2/ episodes of vertigo during the previous 6 months. According to variable response, other drugs (Hydrochlorothiazide, Cinnarizine, Prednisolone or Carbamazepine) were also included. The treatment was considered insufficient if there was no improvement after 1 month, or less than 50% reduction of vertigo seizures after 3 months. In case of pharmacoresistance lasting for 6 months, intratympanic Gentamicin was administered to the affected ear. All patients were advised to keep specific dietary restrictions. Dizzines Handicap Inventory was used to evaluate subjective efficiency of the treatment.

Results & Conclusions: In our study group 64,13% of patients met the ICVD criteria for Probable and 35,86% for Definite Menière’s Disease. We found that 30,8% achieved satisfactory reduction of vertigo attacks by treatment with single administered drug, 52,32% on combination of 2 and 12,23% on 3 prescribed drugs, whereas 4,64% were considered as pharmacoresistant. We observed variable response to the administered drugs, which cannot be exactly predicted on first examination. This can be explained by various factors such as heterogenity of the study group, variable activity of the disease, predominant symptoms, vestibular or other comorbidity, or other medication. Different lifestyle and daily stress level is also assumed to affect the clinical picture, but according to DHI all of the patients reported improvement.

In conclusion we suggest that by thorough investigation, regular follow-ups and adjusting the therapeutic strategy a satisfactory disease control may be achieved within a year in the vast majority of the cases.

FP1083Endoscopic Transcanal Labyrinthectomy for Intractable Meniere’s Disease: An Alternative to Transmastoid Labyrinthectomy?

Se A Lee, Jong Dae Lee

Department of Otorhinolaryngology/Soonchunhyang University Hospital

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Objective: To describe a novel approach for intractable Meniere’s disease exclusively through a transcanal endoscopic ear surgery (TEES) approach.

Patient: A 56-year-old male with intractable Meniere’s disease despite conservative treatment and chemical labyrinthectomy.

Interventions: Transcanal endoscopic labyrinthectomy.

Main Outcome Measure: Subjective vertigo control, surgical morbidity.

Results: The TEES approach provided a wide exposure of the oval window. This facilitated removal of stapes crura and footplate. After widening of the oval window, the perilymph was suctioned, and gentamicin was injected through the oval window. The oval window was obliterated using the perichondrium of the tragal cartilage and fibrin glue. After 2 years of follow-up, there was no recurrence of vertigo.

Conclusions: As a compelling alternative to the transmastoid approach, we propose endoscopic labyrinthectomy as an option for patients with intractable MD without functional hearing who have failed chemical labyrinthectomy.

FP1084Differential Involvement of Lateral Semicircular Canal and Otolith Organs in Common Vestibular Disorders

Yehree Kim¹, Byung Chul Kang², Myung Hoon Yoo³ and Hong Ju Park¹

¹Department of Otorhinolaryngology-Head and Neck Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea;²Department of Otorhinolaryngology-Head and Neck Surgery, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, South Korea; ³Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, Kyungpook National University, Daegu, South Korea

Abstract

Semicircular canal and otolith functions came to be evaluated recently, but comprehensive and comparative analysis of canal and otolith dysfunction in common vestibular disorders is lacking. We aimed to analyze the abnormal rates of canal and otolith function in common vestibular disorders. We enrolled 302 patients who were managed for 2 months in a dizziness clinic. Results of caloric, video head impulse test (vHIT), and cervical and ocular vestibular evoked myogenic potential (cVEMP and oVEMP) tests were analyzed and compared among various diagnoses. Vestibular disorders diagnosed included recurrent vestibulopathy (RV, 27%), vestibular migraine (VM, 21%), benign paroxysmal positional vertigo (BPPV, 17%), Meniere’s disease (MD, 11%), vestibular neuritis (VN, 10%), orthostatic dizziness (7%), and central lesions (3%). Lateral canal dysfunction was found most in VN (100%) and less commonly in definite MD (75%), RV (46%) and definite VM (29%). Abnormal caloric results were more common than abnormal vHIT in all disorders. Otolith dysfunction was found more frequently than lateral canal dysfunction in most vestibular disorders except VN. An abnormal cVEMP was more frequent in definite MD than the other disorders. Isolated otolith dysfunction without lateral canal dysfunction was the most found in BPPV, followed by definite VM, RV, and definite MD in decreasing order. Various patterns of involvement in canal and otoliths were revealed in vestibular disorders, suggesting different pathogenesis.

FP1085Vascular Episodic Dizziness or Vertigo: clinical, diagnostic and therapeutic considerations

Arlindo C. Lima Neto, Roseli S. M. Bittar

Department of Neurotology, Hospital das Clínicas FMUSP, São Paulo, BR.

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Background: Dizziness or vertigo can be the only symptom of posterior circulation (PC) ischemia. In July/2021 the Guideline for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack - AHA/ASA shed light on the treatment of these ischemic conditions. The current study aims to describe symptoms, diagnosis, MRI results and PC blood flow tests (PCBFT) findings (magnetic resonance angiography, computed tomographic angiography and/or transcranial Doppler ultrasound). Dizziness remission and association with test results were evaluated.

Methods: A longitudinal case series of the outpatient Neurotology HC-FMUSP, Brazil was treated from July to October/2021. Subjects with episodic dizziness or vertigo associated to visual darkening, syncope, paresthesia, balance-related fall and/or dysphagia were selected. Patients with non-vascular etiology were excluded. Participants were submitted to anamnesis, bedside tests (including HINTS), MRI, PCBFT. The impact of 3-week-antithrombotic therapy on dizziness was assessed using a visual analogue scale (VAS).

Results: Eight patients (3 males and 5 females), 70,25 +/- 9,27 years old were included. The most frequently observed symptoms were syncope (4/50%) and visual darkening (3/37%). Two subjects (25%) had ischemic signs on MRI and 4 patients (50%) had obstructive findings on PCBFT. Final diagnosis: cerebellar stroke (1/12%), cardioembolic stroke (1/12%), isolated labyrinthine ischemia (1/12%) and TIA (5-62%, one of them due to vertebral artery dissection). After treatment, 6 patients (75%) reported dizziness improvement above 70%, while 2 (25%) reported improvement of 30-50%. No correlation was detected between intensity of symptoms, diagnosis of stroke, PCBFT results or VAS response.

Conclusion: Syncope and visual darkening have been the most frequently symptoms associated with vascular dizziness or vertigo. The most common diagnosis was TIA, but stroke and isolated labyrinthine ischemia were also identified. Half of participants presented PC flow obstruction. Most of them had significant improvement in dizziness or vertigo with antithrombotic therapy. No correlation was detected between intensity of symptoms, diagnosis of stroke, PCBFT results nor treatment response. In the absence of contraindications, early antithrombotic therapy should be considered in patients with vascular dizziness or vertigo.

FP1086Head and Postural Sway Dynamics during a Virtual Reality Dual-Task Standing Paradigm in People with Persistent postural-perceptual dizziness vs. Healthy Controls

Anat V. Lubetzky¹, Moshe M.H. Aharoni², Liraz Arie¹, Tal Krasovsky^2,3

¹Department of Physical Therapy, Steinhardt School of Culture Education and Human Development, New York University, New York, NY, USA; ²Department of Physical Therapy, University of Haifa, Haifa, Israel; ³Pediatric Rehabilitation Department, Sheba Medical Center, Ramat Gan, Israel

Background: Persistent postural-perceptual dizziness (PPPD) is characterized by chronic dizziness and imbalance exacerbated by visual load with normal laboratory testing. Identifying mechanisms of instability in PPPD could drive development of clinical balance assessments and effective rehabilitation programs. This study aimed to evaluate movement strategies in patients with PPPD in complex visual environments under challenging balance and cognitive conditions as compared with healthy adults.

Methods: We tested 22 patients with PPPD diagnosed according to the ICD-11/Bárány Society diagnostic criteria (mean age 32 [21,66], 10 women) and 20 controls (mean age 39, [21,66], 12 women). Participants stood in tandem position (heel-to-toes), wearing the HTC Vive and observing a 3-wall display of stars. The display was either static or moving in the anterior-posterior direction at 0.2 Hz and 5mm amplitude (AP5) or at 0.2 Hz and 32 mm amplitude (AP32). All scenes repeated 4 times in a randomized order: twice with a secondary cognitive task (serial subtraction by 3) and twice without. Anterior-posterior (AP) and medio-lateral (ML) postural sway (center-of-pressure, COP) and head kinematics (from the headset) were recorded. A repeated measures Analysis of Variance assessed main effect of visual (Static, AP5, AP32), task (single, dual) and group (PPPD, control) on directional path and acceleration.

Results: Controls significantly increased all COP and head parameters with the cognitive task whereas PPPD increased only COP ML path and acceleration. Only controls significantly increased head anterior-posterior & medio-lateral acceleration with moving visual load. Cognitive task performance was similar between groups. Between-group comparison showed that the groups were different on the least complex scenes only: the PPPD group was significantly higher (P<0.05) on all head outcome measures for the static single-task scene, and on all outcome measures but ML head acceleration on the AP5 single-task scene.

Conclusion: Balance responses to cognitive and visual load varied between people with PPPD and controls such that controls demonstrated increased movement with increased task difficulty and the PPPD group did not. These altered postural strategies were particularly observed around the head segment. Head-mounted displays thus appear to provide adequate input and output to study postural responses in people with PPPD. Future studies should examine the mechanism underlying altered movement strategies in response to cognitive and visual load in individuals with PPPD and whether reduced head degrees of freedom is adopted to avoid symptom exacerbation.

FP1087Vibration-Induced nystagmus evaluation in a population wtih long-term vestibular neuritis

Marta Chaure-Cordero, Eduardo Martín-Sanz, Jonathan Esteban-Sánchez

Hospital Universitario de Getafe

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Vestibular neuritis (VN) is a clinical entity characterized by acute, prolonged vertigo, constituting one of the most frequent peripheral acute vestibular disorders. The restoration of vestibular function is key on patients suffering this entity and depends on vestibular compensation: restoration, adaptation, and habituation. Skull vibration-induced nystagmus (SVIN) is an easy and replicable tool used to detect minimal vestibular asymmetries. Stimulus at 100Hz activates the vestibular receptors and produces a nystagmus, lacking adaptation. Once the stimulation is over, the nystagmus disappears.

The aim of this project is to study the ocular response after vibration stimulation, its influence, and the mechanisms of vestibular compensation in a population with VN.

Methods: We present a longitudinal cross-sectional study of 40 patients affected with VN of more than 6 month-course diagnosed between January-2017 and July-2019. The population was diagnosed with VN after a congruent clinical history and caloric tests, v-HIT and VEMPs performed. Every patient was put through a new v-HIT of every semicircular canal and a videonystagmography while applying a vibration stimulus at 30, 60 and 100Hz between December-2020 and February-2021. Patients were categorized in three groups depending on restoration of the gain of the vestibulo-ocular reflex, comparing results of v-HIT at diagnosis and time after the beginning of the symptoms.

Results: The group’s median age was 54.63 years, and 60% had their right ear affected . Median time of follow-up was 1,558 days. The median gain on the affected ear after the acute phase of the VN was 0.82 on the horizontal semicircular canal (HSC), 0.84 on the posterior semicircular canal and 0.85 on the SSC. 50% of our patients presented SVIN at 100Hz on the mastoid of the affected ear with a median slow-phase eye velocity of nystagmus of 7.3°/s. In addition, 57.5% presented VIN on the contralateral mastoid at 7.04°/s when stimulating at 100Hz. Patients without restoration showed a more intense VIN than the ones that restored (p<0.05). Besides, significant correlation was shown between the function of the HSC and the nystagmus’ speed. Frequency of VIN was significantly higher in patients in which, despite the long-evolution of VN, still showed overt saccades with an odds ratio of 8.

Conclussion: VIN is an adequate tool to analyze vestibular asymmetries. Its presence seems independent of the mechanisms of vestibular compensation if restoration is not achieved.

FP1095Vestibular functions of adolescents with idiopathic scoliosis: A comprehensive assessment and comparative study

Klára Kucerová¹, Zuzana Balatková², Kryštof Slabý¹, Ondrej Cakrt¹

¹Department of Rehabilitation and Sports Medicine, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital; ²Department of Otorhinolaryngology and Head and Neck Surgery, 1st Faculty of Medicine, Charles University in Prague and Motol University Hospital

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Objective: Idiopathic scoliosis (IS) is characterized by a three-dimensional deformity of the spine with unknown etiopathogenesis. There is evidence that IS may be associated with abnormalities of the vestibular system. Therefore, the purpose of this study was to evaluate vestibular function in adolescents with IS.

Methods: We examined 20 patients with IS and 20 healthy controls. The examination involved assessment of the perception of subjective visual vertical (SVV) in static and dynamic conditions, posturography (six conditions: eyes open/closed, firm/foam surface, tandem stand), and vestibular evoked myogenic potential (VEMP) testing. Results of the tests were compared between the groups.

Results: In SVV, there was no significant difference in static conditions. However, in dynamic conditions, the deviation was significantly greater in patients than in controls (p < 0.05). Posturography parameters of patients were significantly greater (p < 0.05) when standing on a foam surface with eyes open. In this condition, patients had greater center of foot pressure sway area and sway velocity. The patients and controls also differed in terms of sway path, sway velocity, and maximal amplitude in the medial-lateral direction. In VEMP testing, 38% of patients with IS had an abnormal response.

Conclusions: This study provides a comprehensive assessment of vestibular abnormalities in patients with IS. We found greater variations in dynamic SVV, greater values of posturography parameters, and some abnormal VEMP responses in patients with IS. Further studies are needed to find out if vestibular rehabilitation can improve these abnormal functions.

FP1097Evaluation of a New Web-based, Mobile Intervention for Improving Balance Disorders Among Elderly in Residential Home Care: A Prospective Study

Oz Zur^1,2, Hadas Ben-Rubi Shimron¹, Lisa Deutsch³, Eli Carmeli⁴

¹The Israeli Center for Dizziness and Balance Disorders, Raanana, Israel; ²Department of Physical Therapy, Ben Gurion University of the Negev, Beer Sheva, Israel; ³BioStats Statistical Consulting, Ltd., Maccabim, Israel; ⁴Department of Physical Therapy, University of Haifa, Haifa, Israel

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Background: Falls are common among the elderly and sensory integration training can decrease that risk. As people become homebound for many reasons, Tele-medicine and Tele-training have become essential alternatives. This study evaluated the efficacy of the Bbalance application (app), a new web-based, mobile balance rehabilitation program, in improving balance scores, increasing self-confidence and decreasing anxiety. Methods: Forty-one residents of an assisted-living facility, ages 71-94 years, participated and were divided into intervention (n=28) and control groups (n=13). All participants underwent clinical tests for balance (ZBS) and completed self-confidence (ABC) and general anxiety (SAST) questionnaires. The intervention group practiced twice daily using the BBalance app, for one month. Tests were conducted four months before the intervention (T1), at the beginning of intervention (baseline, T2) and at its end (T3).

Results: During T1–T2, ZBS scores between groups were similar (P=0.503). Between T2 and T3, ZBS scores in the intervention group improved significantly compared to controls (P<0.0001). Self-confidence and anxiety showed a trend toward improvement. After using the BBalance app, twice daily for one month, balance scores improved. Anxiety and self-confidence demonstrated a trend toward improvement.

Conclusion: The BBalance app can be a useful tool for balance rehabilitation when Tele-health is required.

FP1100Prebycusis and Presbyvestibulopathy: balance improvement after hearing loss restoration.

Giacinto Asprella Libonati¹, Pasqualina Maria Picciotti², Tiziana Di Cesare², Fernanda Asprella Libonati², Guido Conti²

¹U.O.S.D. Vestibologia e Otorinolaringoiatria Ospedale Giovanni Paolo II, Policoro, Italy; ²Otolaryngology Department, Fondazione Policlinico Universitario “A. Gemelli” – IRCCS, Rome, Italy