Journal of Vestibular Research - Volume 32, issue 4

Authors: Bretl, Kathrine N. | Clark, Torin K.

Article Type: Research Article

Abstract: BACKGROUND: The cross-coupled (CC) illusion and associated motion sickness limit the tolerability of fast-spin-rate centrifugation for artificial gravity implementation. Humans acclimate to the CC illusion through repeated exposure; however, substantial inter-individual differences in acclimation exist, which remain poorly understood. To address this, we investigated several potential predictors of individual acclimation to the CC illusion. METHODS: Eleven subjects were exposed to the CC illusion for up to 50 25-minute acclimation sessions. The metric of acclimation rate was calculated as the slope of each subject’s linear increase in spin rate across sessions. As potential predictors of acclimation rate, we gathered …age, gender, demographics, and activity history, and measured subjects’ vestibular perceptual thresholds in the yaw, pitch, and roll rotation axes. RESULTS: We found a significant, negative correlation (p  = 0.025) between subjects’ acclimation rate and roll threshold, suggesting lower thresholds yielded faster acclimation. Additionally, a leave-one-out cross-validation analysis indicated that roll thresholds are predictive of acclimation rates. Correlations between acclimation and other measures were not found but were difficult to assess within our sample. CONCLUSIONS: The ability to predict individual differences in CC illusion acclimation rate using roll thresholds is critical to optimizing acclimation training, improving the feasibility of fast-rotation, short-radius centrifugation for artificial gravity. Show more

Keywords: Human spaceflight, vestibular perceptual threshold, incremental acclimation, short-radius centrifugation, physiological countermeasure

DOI: 10.3233/VES-210019

Citation: Journal of Vestibular Research, vol. 32, no. 4, pp. 305-316, 2022

Authors: Houben, Mark M.J. | Meskers, Arjan J.H. | Bos, Jelte E. | Groen, Eric L.

Article Type: Research Article

Abstract: BACKGROUND: The vestibular Coriolis illusion is a disorienting sensation that results from a transient head rotation about one axis during sustained body rotation about another axis. Although often used in spatial disorientation training for pilots and laboratory studies on motion sickness, little is known about the minimum required rotation rate to produce the illusion. OBJECTIVE: This study determined the perception threshold associated with the Coriolis illusion. METHODS: Nineteen participants performed a standardized pitching head movement during continuous whole-body yaw rotation at rates varying between 5 to 50 deg/s. The participants reported their motion sensation in relation …to three hypothesized perception thresholds: 1) a sense of undefined self-motion, 2) a sense of rotation, and 3) a sense of rotation and its direction (i.e., the factual Coriolis illusion). The corresponding thresholds were estimated from curves fitted by a generalized linear model. RESULTS: On average threshold 1 was significantly lower (8 deg/s) than thresholds 2 and 3. The latter thresholds did not differ from each other and their pooled value was 10 deg/s. CONCLUSIONS: The Coriolis illusion is perceived at yaw rates exceeding 10 deg/s using a pitching head movement with 40 deg amplitude and 55 deg/s peak velocity. Model analysis shows that this corresponds to an internal rotation vector of 6 deg/s. With this vector the Coriolis perception threshold can be predicted for any other head movement. Show more

Keywords: Spatial disorientation, perception modeling, pilot training

DOI: 10.3233/VES-210073

Citation: Journal of Vestibular Research, vol. 32, no. 4, pp. 317-324, 2022

Authors: Harris, Laurence R. | Jenkin, Michael | Herpers, Rainer

Article Type: Research Article

Abstract: BACKGROUND: Humans demonstrate many physiological changes in microgravity for which long-duration head down bed rest (HDBR) is a reliable analog. However, information on how HDBR affects sensory processing is lacking. OBJECTIVE: We previously showed [25 ] that microgravity alters the weighting applied to visual cues in determining the perceptual upright (PU), an effect that lasts long after return. Does long-duration HDBR have comparable effects? METHODS: We assessed static spatial orientation using the luminous line test (subjective visual vertical, SVV) and the oriented character recognition test (PU) before, during and after 21 days of 6° HDBR in …10 participants. Methods were essentially identical as previously used in orbit [25 ]. RESULTS: Overall, HDBR had no effect on the reliance on visual relative to body cues in determining the PU. However, when considering the three critical time points (pre-bed rest, end of bed rest, and 14 days post-bed rest) there was a significant decrease in reliance on visual relative to body cues, as found in microgravity. The ratio had an average time constant of 7.28 days and returned to pre-bed-rest levels within 14 days. The SVV was unaffected. CONCLUSIONS: We conclude that bed rest can be a useful analog for the study of the perception of static self-orientation during long-term exposure to microgravity. More detailed work on the precise time course of our effects is needed in both bed rest and microgravity conditions. Show more

Keywords: Human orientation perception, space flight analog, subjective visual vertical, perceptual upright, head down bed rest, HDBR

DOI: 10.3233/VES-210016

Citation: Journal of Vestibular Research, vol. 32, no. 4, pp. 325-340, 2022

Authors: Danneels, Maya | Van Hecke, Ruth | Leyssens, Laura | Cambier, Dirk | van de Berg, Raymond | Van de Velde, Laura | Van Rompaey, Vincent | Maes, Leen

Article Type: Research Article

Abstract: PURPOSE: Aside from typical symptoms such as dizziness and vertigo, persons with vestibular disorders often have cognitive and motor problems. These symptoms have been assessed in single-task condition. However, dual-tasks assessing cognitive-motor interference might be an added value as they reflect daily life situations better. Therefore, the 2BALANCE protocol was developed. In the current study, the test-retest reliability of this protocol was assessed. METHODS: The 2BALANCE protocol was performed twice in 20 healthy young adults with an in-between test interval of two weeks. Two motor tasks and five different cognitive tasks were performed in single and dual-task condition. …Intraclass correlation coefficients (ICC), the standard error of measurement, and the minimal detectable difference were calculated. RESULTS: All cognitive tasks, with the exception of the mental rotation task, had favorable reliability results (0.26≤ICC≤0.91). The dynamic motor task indicated overall substantial reliability values in all conditions (0.67≤ICC≤0.98). Similar results were found for the static motor task during dual-tasking (0.50≤ICC≤0.92), but were slightly lower in single-task condition (–0.26≤ICC≤0.75). CONCLUSIONS: The 2BALANCE protocol was overall consistent across trials. However, the mental rotation task showed lowest reliability values. Show more

Keywords: Dual-task, cognition, gait and posture, cognitive-motor interference, test-retest reliability

DOI: 10.3233/VES-210069

Citation: Journal of Vestibular Research, vol. 32, no. 4, pp. 341-353, 2022

Authors: Fröhlich, L. | Wilke, M. | Plontke, S.K. | Rahne, T.

Article Type: Research Article

Abstract: BACKGROUND: Treatment with a cochlear implant (CI) poses the risk of inducing a behaviorally unmeasurable air-bone gap leading to false negative absence of cervical and ocular vestibular evoked myogenic potentials (cVEMPs, oVEMPs) to air conducted sound (ACS). OBJECTIVE: To investigate VEMP response rates to ACS and bone conducted vibration (BCV) in CI patients and the applicability of the B81 transducer for BCV stimulation. METHODS: Prospective experimental study including unilateral CI patients, measuring cVEMPs and oVEMPs to ACS and to BCV, comparing response rates, signed asymmetry ratios, latencies, and amplitudes. RESULTS: Data of 13 CI …patients (mean age 44±12 years) were analyzed. For the CI side, oVEMP and cVEMP response rates were significantly higher for BCV (77%cVEMP, 62%oVEMP) compared to ACS (23%cVEMP, 8%oVEMP). For the contralateral side, no difference between response rates to ACS (85%cVEMP, 69%oVEMP) and BCV (85%cVEMP, 77%oVEMP) was observed. Substantially higher asymmetries were observed for ACS (–88±23%for cVEMPs, –96±11%for oVEMPs) compared to BCV (–12±45%for cVEMPs, 4±74%for oVEMPs). CONCLUSIONS: BCV is an effective stimulus for VEMP testing in CI patients. The B81 is a feasible stimulator. Show more

Keywords: Cochlear implant, vestibular function, VEMP, air conduction, bone conduction, transducer, air-bone gap, asymmetry

DOI: 10.3233/VES-210028

Citation: Journal of Vestibular Research, vol. 32, no. 4, pp. 355-365, 2022

Authors: Baydan-Aran, Mine | Aran, Orkun Tahir | Tokgöz-Yılmaz, Suna

Article Type: Research Article

Abstract: BACKGROUND: International Classification of Functioning, Disability and Health (ICF) has an important role in rehabilitation in terms of assessments. In the field of vestibular rehabilitation, Vestibular Activities of Participation (VAP) measure is the first assessment developed in a perspective of ICF. OBJECTIVE: It was aimed to adapt cross-culturally and analyze psychometric properties of VAP into Turkish Language. METHODS: The VAP was translated into Turkish language by the authors and back translated by a blind native English speaker. The final version was applied to 310 participants. Internal consistency was analyzed with Cronbach’s alpha and test-retest reliability analyzed …with Intraclass Correlation coefficient (ICC). Validity of the scale investigated with Exploratory and Confirmatory Factor analysis (EFA and CFA). RESULTS: Cronbach’s alpha reliability coefficient was found 0.94, and the reliability of the subscales ranged from 0.75 to 0.95; ICC was found 0.94. VAP resulted 8-factor structure and explained 88%of the total variance. In CFA (χ2) / df ratio shows good agreement with 2.472 and the goodness of fit indices of TLI (0.814), CFI (0.893) and RMSEA (0.075) showed acceptable fit. CONCLUSIONS: This study showed that VAP-Turkish version is valid and reliable in Turkish speaking populations, and might be used to determine impact of vestibular disorders on activities and participation. Show more

Keywords: Vestibular diseases, psychometrics, audiology, participation, activities of daily living

DOI: 10.3233/VES-210094

Citation: Journal of Vestibular Research, vol. 32, no. 4, pp. 367-372, 2022

Authors: Teh, Carren Sui-Lin | Prepageran, Narayanan

Article Type: Research Article

Abstract: BACKGROUND: Persistent Postural-Perceptual Dizziness (PPPD) is a chronic functional disorder which interferes with the way individuals experience their personal, social and work life. OBJECTIVE: To study the impact of disease duration in PPPD on the quality of life (QOL), dizziness handicap and mental health on the patients. METHODS: A prospective study comparing the EQ-5D for QOL, Dizziness Handicap Inventory (DHI) and DASS-21 between 27 patients with PPPD and 27 of those who have recovered from an acute vestibular event. Similar parameters between PPPD patients with symptoms less than one year and more than a …year were compared. RESULTS: The PPPD patients were predominantly females and middle-aged with significantly higher DHI scores (mean 48.3 + 25.7, p  = 0.00002), higher total mean scores in the DASS-21 (mean 21.6 + 13.7, p  = 0.009) and poorer QOL with mean EQ-5D VAS of 67.9 + 17.3 (p  < 0.00001). PPPD patients with symptoms for more than a year had significant increase in physical handicap (p  = 0.041) as well as anxiety levels (p  = 0.008). CONCLUSIONS: PPPD is predominantly seen in females and middle-aged which significantly reduces the QOL, increases dizziness handicap and increases depression, anxiety and stress levels. The increase in duration of illness further increases the anxiety levels and physical handicap. Show more

Keywords: Persistent Postural-Perceptual Dizziness, dizziness handicap, quality of life, depression, anxiety

DOI: 10.3233/VES-210087

Citation: Journal of Vestibular Research, vol. 32, no. 4, pp. 373-380, 2022

Authors: Millar, Jennifer L. | Schubert, Michael C.

Article Type: Research Article

Abstract: BACKGROUND: Patients with cerebellar ataxia report oscillopsia, “bouncy vision” during activity, yet little is known how this impacts daily function. The purpose of this study was to quantify the magnitude of oscillopsia and investigate its relation to vestibulo-ocular reflex (VOR) function and daily activity in cerebellar ataxia. METHODS: 19 patients diagnosed with cerebellar ataxia and reports of oscillopsia with activity were examined using the video head impulse test (vHIT), Oscillopsia Functional Index (OFI), and clinical gait measures. Video head impulse data was compared against 40 healthy controls. RESULTS: OFI scores in ataxia patients …were severe and inversely correlated with gait velocity (r  = –0.55, p  < 0.05), but did not correlate with VOR gains. The mean VOR gain in the ataxic patients was significantly reduced and more varied compared with healthy controls. All patients had abnormal VOR gains and eye/head movement patterns in at least one semicircular canal during VHIT with passive head rotation. CONCLUSIONS: Patients with cerebellar ataxia and oscillopsia have impaired VOR gains, yet severity of oscillopsia and VOR gains are not correlated. Patients with cerebellar ataxia have abnormal oculomotor behavior during passive head rotation that is correlated with gait velocity, but not magnitude of oscillopsia. Show more

Keywords: Oscillopsia, cerebellar ataxia, vestibular ocular reflex, gaze stability, gait

DOI: 10.3233/VES-210106

Citation: Journal of Vestibular Research, vol. 32, no. 4, pp. 381-388, 2022