Journal of Vestibular Research-Equilibrium & Orientation最新文献

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.

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.

Background: The subjective visual vertical (SVV) test is a sensitive test of vestibular dysfunction that allows the evaluation of otolithic organs; however, with the current method, there are technical and logistical limitations that make the application of this test difficult in the conventional clinic.

Objective: The objective of this study is to assess the effectiveness of detecting vestibular pathology using the SVV via a new screening method.

Methods: A consecutive sample of 62 patients with suspected vestibular pathology was included in the study. The patients were clinically diagnosed according to the Barany Society criteria. An exploratory system was designed using a mobile application in Android that detects accelerometer oscillations and involves placing the smartphone on a rotating disk anchored to the wall. All patients underwent a SVV examination using the bucket method and the study test. A cut-off point of the ROC curve was calculated for each test, and its sensitivity, specificity, diagnostic accuracy and probability ratios for detecting vestibular pathology were analysed. The SVV results were compared using the bucket test and the study test.

Results: We observed significant differences in sensitivity between the two tests: 86.95% for the study test versus 67.4% for the bucket test (p < 0.01). In the ROC curve, an area under the curve of 0.90 was observed for the study test, with a cut-off of 2.43 for a sensitivity of 86.95% and a specificity of 93.75%.

Conclusions: SVV testing using a smartphone placed on a rotating disk anchored to the wall offers greater diagnostic accuracy than SVV using the bucket test. Both methods are inexpensive, harmless and easily accepted by patients.

Background: Self-motion misperception has been observed in vestibular patients during asymmetric body oscillations. This misperception is correlated with the patient's vestibular discomfort.

Objective: To investigate whether or not self-motion misperception persists in post-ictal patients with Ménière's disease (MD).

Methods: Twenty-eight MD patients were investigated while in the post-ictal interval. Self-motion perception was studied by examining the displacement of a memorized visual target after sequences of opposite directed fast-slow asymmetric whole body rotations in the dark. The difference in target representation was analyzed and correlated with the Dizziness Handicap Inventory (DHI) score. The vestibulo-ocular reflex (VOR) and clinical tests for ocular reflex were also evaluated.

Results: All MD patients showed a noticeable difference in target representation after asymmetric rotation depending on the direction of the fast/slow rotations. This side difference suggests disruption of motion perception. The DHI score was correlated with the amount of motion misperception. In contrast, VOR and clinical trials were altered in only half of these patients.

Conclusions: Asymmetric rotation reveals disruption of self-motion perception in MD patients during the post-ictal interval, even in the absence of ocular reflex impairment. Motion misperception may cause persistent vestibular discomfort in these patients.

Background: Vestibular drop attacks (VDA), also called Tumarkin otolith crises as a complication of Ménière's disease (MD) were first described in 1936. Nevertheless, a clearer understanding of their prevalence and manifestations is needed.

The objective: of this review is to determine the frequency, correlates and consequences of VDA in MD.

Method: Three databases were searched (i.e., MEDLINE, PubMed and Google Academia). A total of 1,791 references were identified, of which 18 studies were considered eligible. There was a large variation in the definition of VDA used in the studies.

Results: The frequency of VDA in MD leading to a fall to the ground varied from 3 to 19% in 9 hospital-based studies. In studies where a less restrictive definition of VDA included attacks with postural perturbation, tripping and near-to-fall situations was used the prevalence ranged from 50 to 72%. The pooled frequency of VDA leading to fall to the ground was 8% (95% CI 4 to 12%) in hospital-based studies. In these studies, VDA often occurred in severe and advanced MD whereas in cohort studies such connection was not found. Co-morbidity with migraine increased the likelihood of VDA occurrence in MD. In 3 studies syncope was recorded in connection to VDA with falls. In terms of clinical manifestation, audiometry, MRI, vestibular evoked muscle response measures indicated endolymphatic hydrops with involvement of the otolith system. The hearing loss was more pronounced, and balance was worse in MD patients with VDA than in those without. Injury associated with VDA was reported in only one study.

Conclusions: VDA is a common phenomenon in MD, occurring even in mild MD and complicated with syncope. Some preliminary evidence suggests that VDA may lead to severe injuries.

Background: fHIT is an easily applicable test battery that indirectly evaluates the vestibulo-ocular reflex (VOR) from a functional perspective.

Aims/objectives: The aim of this study was to Individuals determine the correlation between age and the percentage of correct answers (%CA) obtained in the functional head impulse test (fHIT) in healthy individuals.

Material and methods: A total of 105 volunteers, 50 males and 55 females, between the ages of 18 and 70 years, participated in the study. A Beon Solution fHIT system (Zero Branco (TV), Italy) was used in the study.

Results: In our study, a decrease in the mean %CA was observed in all semicircular canals (SCCs) with increasing age. Between age and mean %CA, a significant negative moderate (-0.311) correlation was observed in lateral SCCs, and a significant negative low (-0.257) correlation was observed in posterior SCCs (p < 0.05). In anterior SCCs, there was no statistically significant relationship between age and mean %CA (p > 0.05).

Conclusions: The present study performed in a healthy population will be helpful in terms of making comparisons in studies to be conducted in various vestibular diseases. It will also be a guide for identifying pathological consequences in vestibular diseases.

Background: Avoidance of activities that trigger dizziness in persons with vestibular disorders may inhibit dynamic vestibular compensation mechanisms.

Objective: To determine the reliability of the Vestibular Activities Avoidance Instrument (VAAI) 81 and 9 item tool and to compare the VAAI scores in Dutch-speaking healthy adults and in patients with vestibular disorders.

Methods: A prospective cohort study was conducted including 151 healthy participants and 106 participants with dizziness. All participants completed the 81-item VAAI. Within 7 days, the VAAI was completed a second time by 102 healthy adults and 43 persons with dizziness.

Results: The average 81-item VAAI scores [54.8(47.1) vs. 228.1(78.3)] and 9-item VAAI scores [2.4(5.9) vs. 28.1(12)] were significantly different between healthy adults and participants with dizziness (p < 0.001). In participants with dizziness the ICC for the 81-item VAAI was 0.95 (95% CI: 0.91, 0.97) and for the 9-item VAAI was 0.92 (95% CI: 0.85, 0.95). Cronbach's alpha for the 81-item VAAI was 0.97 and 0.85 for the 9-item VAAI. The minimal detectable change was 47.8 for the 81-item VAAI and 8.9 for the 9-item VAAI.

Conclusions: Persons with dizziness have a greater tendency to avoid movements. Both test-retest reliability and internal consistency of the Dutch version of the VAAI were excellent.

Background: The caloric vestibular test (CVT) may evoke headache and vestibular symptoms in susceptible people. Patients with migraines have higher susceptibility to motion sickness. In migraines, impaired habituation to repetitive stimuli is a well-known interictal abnormality.

Objective: This study is aimed at evaluating CVT-evoked headache, nausea, vomiting, and imbalance in patients with and without migraine and/or motion sickness.

Methods: A retrospective data analysis was performed on 554 patients with a complaint of dizziness who underwent bithermal CVT at a tertiary referral center. The occurrences of CVT-evoked headache, nausea, vomiting, and imbalance were observed in four groups: patients with only migraine (MG; n = 94), those with only motion sickness (MSG; n = 89), those with migraine and motion sickness (MMSG; n = 122), and those without migraine and motion sickness (non-MMSG; n = 146). The differences between the groups were assessed.

Results: The mean ages of groups were similar (p = 0.534). The proportions of females were higher in the MG, MSG, and MMSG (p = 0.001). The severity of nausea and headache for each gender was higher in the MG, MSG, and MMSG (p < 0.001). Vomiting was more common in MMSG among males (p = 0.003), while there was no difference between groups among females (p = 0.099). Imbalance was more common in MMSG among females (p < 0.001). A relationship was detected between age and imbalance (p < 0.001), where an increased risk for imbalance was evident with greater age. Three patients in the MMSG needed hospitalization after CVT.

Conclusions: Special caution is needed when performing caloric testing for patients with migraines or MS since CVT-evoked symptoms may occur with higher incidence and intensity, which might be related to a lack of habituation in neuronal information processing after robust sensory stimuli like CVT.

Background: Virtual reality (VR) use as a platform for vestibular rehabilitation is widespread. However, the utility of VR based vestibular assessments remains unknown.

Objective: To compare dynamic visual acuity (DVA) scores, perceived balance, and perceived dizziness when using traditional versus VR environments for DVA testing among healthy individuals.

Methods: DVA testing occurred for both a traditional clinical protocol and in a VR variant. Horizontal, vertical, and no head motion conditions were conducted for both clinical and VR test protocols. DVA scores, balance ratings, and dizziness ratings were obtained per condition. Two-way ANOVAs with repeated measures were used to assess differences in DVA scores, balance, and dizziness ratings.

Results: No differences in DVA results, balance or dizziness ratings were observed when comparing traditional clinical protocol versus the VR variant. Differences across head motion conditions were observed, with no motion trials exhibiting significantly higher DVA scores and perceived balance, and lower perceived dizziness compared to vertical and horizontal head motion. Vertical head motion exhibited this same trend compared to horizontal.

Conclusion: DVA testing conducted in VR demonstrated clinical utility for each measure. Effects of head motion were similar across test variants, indicating DVA testing in VR produces similar effects on vestibular function than traditional clinical testing. Additional research should be conducted to assess the feasibility of VR assessment in individuals with vestibular disorder.

Background: Galvanic vestibular stimulation (GVS) is believed to be one of the most valuable tools for studying the vestibular system. In our opinion, its combined effect on posture and perception needs to be examined more.

Objective: The present study was conducted to investigate the effect of a 20 Hz sinusoidal Galvanic Vestibular Stimulation (sGVS) on the body sway and subjective visual vertical (SVV) deviation through two sets of electrode montages (bipolar binaural and double temple-mastoidal stimulation) during a three-stage experiment (baseline, threshold, and supra-threshold levels).

Methods: While the individuals (32 normal individuals, 10 males, the mean age of 25.37±3.00 years) were standing on a posturography device and SVV goggles were put on, the parameters of the body sway and SVV deviation were measured simultaneously. Following the baseline stage (measuring without stimulation), the parameters were investigated during the threshold and supra-threshold stages (1 mA above the threshold) for 20 seconds. This was done separately for each electrode montage. Then, the results were compared between the three experimental stages and the two electrode montages.

Results: In both electrode montages, "the maximum amplitude" of the mediolateral (ML) and anteroposterior (AP) body sway decreased and increased in the threshold and supra-threshold stages, respectively, compared to the baseline stage. Comparison of the amount of  "amplitude change" caused by each electrode montages showed that the double temple-mastoidal stimulation induced a significantly greater amplitude change in body sway during both threshold and supra-threshold stages (relative to the baseline stage).The absolute mean values of the SVV deviation were significantly different between the baseline and supra-threshold levels in both electrode montages. The SVV deviation in double temple-mastoidal stimulation was a bit greater than that in the bipolar binaural stimulation.

Conclusion: Double temple-mastoidal stimulation has induced greater amount of change in the body sway and SVV deviation. This may be due to the more effective stimulation of the otoliths than semicircular canals.