Journal of Vestibular Research - Volume 33, issue 1

Authors: Tribukait, Arne | Bergsten, Eddie | Brink, Andreas | Eiken, Ola

Article Type: Research Article

Abstract: BACKGROUND: During a simulated coordinated turn in a gondola centrifuge, experienced pilots show a substantial inter-individual variability in visual measures of perceived roll tilt. Because of the centrifuge’s small radius, the pattern of stimuli to the semicircular canals during acceleration of the centrifuge differs in certain respects from that of an aircraft entering a turn. OBJECTIVE: To explore whether these differences may be of significance for the pilot’s roll- plane orientation and whether individual characteristics revealed in the centrifuge correspond to those during real flight. METHOD: 8 fixed-wing air-force pilots were tested in a centrifuge and …a high-performance aircraft. The centrifuge was accelerated to 2 G (gondola inclination 60°) within 10 s. The duration at 2 G was 6 minutes. Similar profiles were created in the aircraft. The subjective visual horizontal (SVH) was measured using an adjustable luminous line in darkness. Each pilot was tested on three occasions: centrifuge (2 runs), aircraft (2 turns), centrifuge (2 runs). For each 2-G exposure, initial and final SVH values were established via curve fitting. RESULT: Despite a large inter-individual variability (±SD), group means were similar in the aircraft (initial: 43.0±20.6°; final: 22.5±14.8°) and centrifuge (initial: 40.6±17.0°; final: 20.5±16.0°). Further, individual peculiarities in response patterns were similar in the two conditions. For both the initial and final SVH tilt there was a high correlation between centrifuge and aircraft. CONCLUSION: The correspondence between conditions suggests that the centrifuge is an adequate means for demonstrating the fundamental motion pattern of coordinated flight and also for establishing the individual pilot’s ability to perceive an aircraft’s roll attitude. Findings are discussed in connection with vestibular learning and the possibility of underlying differences between pilots in the keenness for semicircular canal and somatosensory cues. Show more

Keywords: Vestibular system, vestibular psychophysics, spatial disorientation, subjective horizontal, subjective vertical

DOI: 10.3233/VES-220016

Citation: Journal of Vestibular Research, vol. 33, no. 1, pp. 1-19, 2023

Authors: Gallagher, M. | Romano, F. | Bockisch, C.J. | Ferrè, E.R. | Bertolini, G.

Article Type: Research Article

Abstract: BACKGROUND: The vestibular system provides a comprehensive estimate of self-motion in 3D space. Widely used to artificially stimulate the vestibular system, binaural-bipolar square-wave Galvanic Vestibular Stimulation (GVS) elicits a virtual sensation of roll rotation. Postural responses to GVS have been clearly delineated, however quantifying the perceived virtual rotation vector has not been fully realised. OBJECTIVE: We aimed to quantify the perceived virtual roll rotation vector elicited by GVS using a psychophysical approach on a 3D turntable. METHODS: Participants were placed supine on the 3D turntable and rotated around the naso-occipital axis while supine and received square-wave …binaural-bipolar GVS or sham stimulation. GVS amplitudes and intensities were systematically manipulated. The turntable motion profile consisted of a velocity step of 20°/s2 until the trial velocity between 0–20°/s was reached, followed by a 1°/s ramp until the end of the trial. In a psychophysical adaptive staircase procedure, we systematically varied the roll velocity to identify the exact velocity that cancelled the perceived roll sensation induced by GVS. RESULTS: Participants perceived a virtual roll rotation towards the cathode of approximately 2°/s velocity for 1 mA GVS and 6°/s velocity for 2.5 mA GVS. The observed values were stable across repetitions. CONCLUSIONS: Our results quantify for the first time the perceived virtual roll rotations induced by binaural-bipolar square-wave GVS. Importantly, estimates were based on perceptual judgements, in the absence of motor or postural responses and in a head orientation where the GVS-induced roll sensation did not interact with the perceived direction of gravity. This is an important step towards applications of GVS in different settings, including sensory substitution or Virtual Reality. Show more

Keywords: Vestibular system, Galvanic Vestibular Stimulation, natural vestibular stimulation, vestibular perception

DOI: 10.3233/VES-220031

Citation: Journal of Vestibular Research, vol. 33, no. 1, pp. 21-30, 2023

Authors: Debenham, M.I.B. | Grantham, T.D.A. | Smirl, J.D. | Foster, G.E. | Dalton, B.H.

Article Type: Research Article

Abstract: BACKGROUND: Hypoxia influences standing balance and vestibular function. OBJECTIVE: The purpose here was to investigate the effect of hypoxia on the vestibular control of balance. METHODS: Twenty participants (10 males; 10 females) were tested over two days (normobaric hypoxia and normoxia). Participants stood on a force plate (head rotated leftward) and experienced random, continuous electrical vestibular stimulation (EVS) during trials of eyes open (EO) and closed (EC) at baseline (BL), after 5 (H1), 30 (H2) and 55-min (H3) of hypoxia, and 10-min into normoxic recovery (NR). Vestibular-evoked balance responses were quantified using cumulant density, coherence, and …gain functions between EVS and anteroposterior forces. RESULTS: Oxyhemoglobin saturation, end-tidal oxygen and carbon dioxide decreased for H1-3 compared to BL; however, end-tidal carbon dioxide remained reduced at NR with EC (p ≤0.003). EVS-AP force peak-to-peak amplitude was lower at H3 and NR than at BL (p ≤0.01). At multiple frequencies, EVS-AP force coherence and gain estimates were lower at H3 and NR than BL for females; however, this was only observed for coherence for males. CONCLUSIONS: Overall, vestibular-evoked balance responses are blunted following normobaric hypoxia >30 min, which persists into NR and may contribute to the reported increases in postural sway. Show more

Keywords: Hypoxia, low oxygen, balance control, vestibular system, electrical vestibular stimulation

DOI: 10.3233/VES-220075

Citation: Journal of Vestibular Research, vol. 33, no. 1, pp. 31-49, 2023

Authors: AlSharif, Doaa S. | Tucker, Carole A. | Coffman, Donna L. | Keshner, Emily A.

Article Type: Research Article

Abstract: INTRODUCTION: No reliable biometric measurement of vestibular involvement with migraine is currently available. OBJECTIVE: Measures of autonomic nervous system and postural responses could serve as quantifiable indicators of vestibular involvement with migraine. METHODS: A convenience sample of 22 young healthy adults (34±9 years old) and 23 young adults (34±8 years old) diagnosed with vestibular migraine (VM) participated. A rod and frame test and clinical outcome measures of dizziness and mobility were administered. Participants stood on foam while viewing two dynamic virtual environments. Trunk acceleration in three planes and electrodermal activity (EDA) were assessed with …wearable sensors. Linear mixed models were used to examine magnitude and smoothness of trunk acceleration and tonic and phasic EDA. A Welch’s t -test and associations between measures were assessed with a Pearson Correlation Coefficient. Effect sizes of group mean differences were calculated using Cohen’s d. RESULTS: Visual dependence was present in 83% of the VM population. Individuals with VM exhibited lower baseline EDA (t(4.17) = –7.2, p  = 0.001) and greater normalized trunk accelerations in the vertical (t(42.5) = 2.861, p  = 0.006) and medial (t(46.6) = 2.65, p  = 0.01) planes than healthy participants. Tonic EDA activity increased significantly across the period of the trial (F (1,417) = 23.31, p  = 0.001) in the VM group. Significant associations appeared between vertical trunk acceleration and EDA, Dizziness Handicap Inventory, and Activities of Balance Confidence tools. CONCLUSIONS: Higher tonic EDA activity in healthy adults results in more accurate postural reactions. Results support the supposition that EDA activity and postural acceleration are significantly different between VM and healthy individuals when accommodating for postural instability and visual-vestibular conflict. Show more

Keywords: Vestibular migraine, virtual reality, autonomic nervous system, VVM, otoliths

DOI: 10.3233/VES-220004

Citation: Journal of Vestibular Research, vol. 33, no. 1, pp. 51-62, 2023

Authors: Demirhan, Mehmet Alp | Celebisoy, Nese

Article Type: Research Article

Abstract: BACKGROUND: Cognitive deficits have been defined in patients with bilateral and unilateral vestibular loss. OBJECTIVE: To investigate cognitive functions in patients with episodic vestibular disorders. METHODS: Nineteen patients with Meniere’s disease (MD), 19 patients with vestibular migraine (VM) and 21 age and education matched healthy controls were studied. Mini Mental State Examination assessing global mental status, Reading Span Test and the Stroop Test evaluating working memory, cognitive processing, reading comprehension and attention, Trail Making Test and Benton’s Judgment of Line Orientation Test investigating visual processing, visuospatial skills, processing speed were used. Beck depression and anxiety inventories …were given to evaluate the emotional status. RESULTS: Cognitive test results of the MD and VM patients were not significantly different from the healthy controls (p  > 0.05) as well as Beck depression scores (p  = 0.14). Beck anxiety scores showed significant difference (p  = 0.003). VM patients had significantly higher scores than the healthy controls (p  = 0.002) on pairwise comparisons. The scores of the MD patients did not reach statistical significance (p  = 0.15). CONCLUSION: Episodic vestibular disorders like MD and VM without inter-ictal vestibular deficits do not seem to be associated with cognitive impairment. Patients with VM have significantly higher anxiety scores than the healthy controls and MD patients. Show more

Keywords: Meniere’s disease, vestibular migraine, cognition, anxiety, depression

DOI: 10.3233/VES-220025

Citation: Journal of Vestibular Research, vol. 33, no. 1, pp. 63-70, 2023

Authors: Micarelli, Alessandro | Viziano, Andrea | Carbini, Valentina | Misici, Ilaria | Guzzo, Federico | Micarelli, Beatrice | Alessandrini, Marco

Article Type: Research Article

Abstract: Background: Unilateral vestibular hypofunction (UVH) may lead to modifications on metabolism and body composition. Vestibular rehabilitation (VR) demonstrated its effectiveness in ameliorating balance function and several other daily-living aspects. Objectives: The aim of this study was to evaluate metabolic composition, by means of bioelectrical impedance analysis (BIA) and daily activity, with the use of a wrist-worn movement tracker, in UVH participants before and after VR, and to compare data with a healthy control group (CG) of adults. Methods: 46 UVH and 60 CG participants underwent otoneurological testing, self-report and performance questionnaires, BIA, and wore a device …tracking daily movement and energy expenditure for one full day; this was performed before and after VR. Results: UVH participants demonstrated a significant (p  = 0.008) increase in muscle mass after VR, and, when compared to CG, no differences were present with respect to visceral fat and muscle mass. UVH adults reported a significant increase in energy expenditure spent in movement (p  = 0.008) and during the day (p  = 0.009), daily number of strides (p  = 0.009) and calories spent in sweeping (p  = 0.009) and stairing (p  = 0.008). Conclusions: Results from this study show that VR provided an improvement of metabolic function and body composition of people with UVH, possibly by contrasting structural modifications in neural pathways stemming from the vestibular nuclei and connected to autonomous function. Show more

Keywords: Vestibular hypofunction, vestibular rehabilitation, movement tracker, bioelectrical impedance analysis, body composition

DOI: 10.3233/VES-220019

Citation: Journal of Vestibular Research, vol. 33, no. 1, pp. 71-83, 2023

Authors: van de Berg, Raymond | Ramos, Angel | van Rompaey, Vincent | Bisdorff, Alexandre | Perez-Fornos, Angelica | Rubinstein, Jay T. | Phillips, James O. | Strupp, Michael | Della Santina, Charles C. | Guinand, Nils

Article Type: Correction

DOI: 10.3233/VES-229001

Citation: Journal of Vestibular Research, vol. 33, no. 1, pp. 85-85, 2023

Authors: Strupp, Michael | Kim, Ji-Soo | Murofushi, Toshihisa | Straumann, Dominik | Jen, Joanna C. | Rosengren, Sally M. | Della Santina, Charles C. | Kingma, Herman

Article Type: Correction

DOI: 10.3233/VES-229002

Citation: Journal of Vestibular Research, vol. 33, no. 1, pp. 87-87, 2023