scholarly journals Is regression gain or instantaneous gain the most reliable and reproducible gain value when performing video head impulse testing of the lateral semicircular canals?

2021 ◽  
Vol 31 (3) ◽  
pp. 151-162
Author(s):  
Chris L. Jacobsen ◽  
Emil R. Abrahamsen ◽  
Regitze K. Skals ◽  
Dan D. Hougaard
Keyword(s):  
Semicircular Canals ◽  
Head Impulse Test ◽  
Calculation Methods ◽  
Dizziness Handicap Inventory ◽  
Head Impulse ◽  
Ocular Reflex ◽  
Vestibular Ocular Reflex ◽  
Significant Difference ◽  
Secondary Endpoints ◽  
Experienced Examiner

BACKGROUND: Several different video Head Impulse Test (vHIT) systems exist. The function of each individual semicircular canal (SCC) may be determined by performing this test. All vHIT systems provide information about the function of the vestibular ocular reflex by means of two modalities: SACCADES and GAIN. However, different gain calculation methods exist. OBJECTIVE: Primary endpoint: • Is instantaneous gain or regression gain the most reproducible and reliable gain value when performing vHIT with testing of the lateral SCCs? Secondary endpoints: • Comparison of each of the instantaneous gain values at 40, 60, and 80ms with the regression gain. • Examination of any intra- and inter examiner variability. • Mean instantaneous gain values, and at different velocities, compared with regression gain values of the lateral SCCs. METHODS: 60 subjects between 18–65 years were included. All patients filled out the Dizziness Handicap Inventory (DHI) questionnaire and underwent four separate vHIT tests, two by an experienced neurotologist and two by an inexperienced examiner. RESULTS/CONCLUSIONS: 240 datasets were obtained, displaying both regression and instantaneous gain values. Regression gain was more reproducible than instantaneous gain. The experienced examiner provided the most reproducible results. When comparing instantaneous gain, we found the gain at 40 ms to be the least reproducible. There was no significant difference between 60 ms and 80 ms.For both examiners no significant intra examiner variability was found.

Viewing Target Distance Influences the Vestibulo-Ocular Reflex Gain when Assessed Using the Video Head Impulse Test

2018 ◽  
Vol 23 (5) ◽  
pp. 285-289 ◽  
Author(s):  
Patricia Castro ◽  
Sara Sena Esteves ◽  
Florencia Lerchundi ◽  
David Buckwell ◽  
Michael A. Gresty ◽  
...  
Keyword(s):  
Head Movements ◽  
Target Distance ◽  
Head Impulse Test ◽  
Video Head Impulse Test ◽  
Gaze Stabilization ◽  
Head Impulse ◽  
Ocular Reflex ◽  
Significant Difference ◽  
Vestibulo Ocular Reflex ◽  
Reflex Gain

Gaze stabilization during head movements is provided by the vestibulo-ocular reflex (VOR). Clinical assessment of this reflex is performed using the video Head Impulse Test (vHIT). To date, the influence of different fixation distances on VOR gain using the vHIT has not been explored. We assessed the effect of target proximity on the horizontal VOR using the vHIT. Firstly, we assessed the VOR gain in 18 healthy subjects with 5 viewing target distances (150, 40, 30, 20, and 10 cm). The gain increased significantly as the viewing target distance decreased. A second experiment on 10 subjects was performed in darkness whilst the subjects were imagining targets at different distances. There were significant inverse relationships between gain and distance for both the real and the imaginary targets. There was a statistically significant difference between light and dark gains for the 20- and 40-cm distances, but not for the 150-cm distance. Theoretical VOR gains for different target distances were calculated and compared with those found in light and darkness. The increase in gain observed for near targets was lower than predicted by geometrical calculations, implying a physiological ceiling effect on the VOR. The VOR gain in the dark, as assessed with the vHIT, demonstrates an enhancement associated with a reduced target distance.

scholarly journals Vestibulo-ocular reflex gain and compensatory saccades in three semicircular canals by video head impulse test

2019 ◽  
Author(s):  
Homa Zarrinkoob ◽  
Hadi Behzad ◽  
Seyed Mehdi Tabatabaee
Keyword(s):  
High Velocity ◽  
Semicircular Canals ◽  
Head Impulse Test ◽  
Video Head Impulse Test ◽  
Low Velocity ◽  
Head Impulse ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Reflex Gain ◽  
The Right

Background and Aim: One of the tools for ass­essing the vestibulo-ocular reflex (VOR) is using video head impulse test (vHIT). In this test by placing the head at different angles and shaking the head, three semicircular canals of the vestibular system in each ear can be exami­ned separately. The purpose of this study was to investigate the relationship between the low and high velocities of the vHIT test with VOR and its compensatory saccades. Methods: The vHIT test was performed by an examiner in 49 normal individuals aged 23–39 at low and high velocities. All participants had normal hearing, visual, and vestibular systems. Results: Mean gains in the horizontal, anterior and posterior semicircular canals in the right ear respectively were 0.92, 1 and 0.90 and in the left ear 0.93, 0.99 and 0.95 for low velocity and 0.78, 0.92 and 0.79 in the right ear and 0.80, 0.85 and 0.86 in the left ear for high velocity. Also, the number of compensatory saccade at high velocity was higher than those at the low velocity and the latency of compensatory sacc­ade was lower at the higher velocity. Conclusion: In the vHIT test, VOR gain decreases at high velocity that is statistically significant. Also, compensatory saccades are more likely to occur at high velocity with sma­ller delay. Therefore, high-velocity vHIT test is not recommended for the purpose of examining the VOR gain and compensatory saccade.

scholarly journals Evaluation of Interexaminer Variability in Video Head Impulse Test Results

2020 ◽  
Vol 31 (08) ◽  
pp. 613-619
Author(s):  
Başak Mutlu ◽  
Sıdıka Cesur ◽  
Merve Torun Topçu ◽  
Cennet Reyyan Geçici ◽  
Öyküm Esra Aşkın ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Semicircular Canals ◽  
Head Impulse Test ◽  
Video Head Impulse Test ◽  
Head Impulse ◽  
Lateral Canal ◽  
Ocular Reflex ◽  
Left Posterior ◽  
Vestibulo Ocular Reflex ◽  
The Right

Abstract Objective The video head impulse test (vHIT) is a diagnostic tool to assess the function of the semicircular canals and branches of the vestibular nerve. The aim of this study was to analyze the interexaminer variability of vHIT results in healthy subjects. Materials and Methods A total of 21 healthy participants were included in the study. vHIT responses were collected by four clinicians. Variability of the vHIT results between examiners was analyzed statistically. Results The vestibulo-ocular reflex (VOR) velocity regression values were from 0.99 to 1.09 degrees per second for the lateral canals. For the vertical canals, VOR velocity regression values were from 0.87 to 1.21 degrees per second. According to repeated measures analysis of variance, the normality assumptions for the velocity regression of the left lateral canal (p = 0.002) and the right anterior canal (p < 0.01) were met and the differences were statistically significant. The normality assumptions were not met for 40, 60, and 80 ms median gain of the right lateral canal (p = 0.016, p = 0.038, and p = 0.001, respectively); 40 and 60 ms median gain of the left lateral canal (p < 0.001 and p = 0.008, respectively); and the velocity regression of the left posterior canal (p < 0.00). These differences were found to be statistically significant by using the Friedman test. Conclusion The interexaminer differences of the VOR gain values for the vHIT were statistically significant. Serial vHIT testing should be performed by the same examiner to reduce the effects of interexaminer variability.

Report of oscillopsia in ataxia patients correlates with activity, not vestibular ocular reflex gain

2021 ◽  
pp. 1-9
Author(s):  
Jennifer L. Millar ◽  
Michael C. Schubert
Keyword(s):  
Cerebellar Ataxia ◽  
Head Rotation ◽  
Gait Velocity ◽  
Head Impulse Test ◽  
Healthy Controls ◽  
Head Impulse ◽  
Ocular Reflex ◽  
Vestibular Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Reflex Gain

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.

scholarly journals Does vestibulo-ocular reflex gain measured by video head impulse test decrease with age?

2021 ◽  
Vol 7 (5) ◽  
pp. 712
Author(s):  
Yijin Jereme Gan ◽  
Yih Meei Heng ◽  
Shailesh Khode ◽  
Aruni Seneviratna ◽  
Annabelle Leong
Keyword(s):  
Semicircular Canal ◽  
Semicircular Canals ◽  
Community Dwelling ◽  
Head Impulse Test ◽  
Video Head Impulse Test ◽  
Head Impulse ◽  
Ocular Reflex ◽  
Age Dependent ◽  
Vestibulo Ocular Reflex ◽  
The Mean

<p class="abstract"><strong>Backgrounds:</strong> The Video Head Impulse Test (vHIT) is used to test the function of each of the six semicircular canals. Each semicircular canal is tested by measuring eye rotation in response to head movements in the plane of the canal and is calculated as the Vestibulo-ocular reflex (VOR) gain. The aims of the study were firstly, to determine age-dependent normative values of VOR gain for the vHIT of semicircular canal function in healthy Asian subjects in each decade year of life. Secondly, to investigate if vHIT measured VOR gain decreases with age.</p><p class="abstract"><strong>Methods: </strong>A prospective cohort study of 60 healthy voluntary community-dwelling subjects, between 21 to 80 years of age. Subjects with prior history of vertigo were excluded. vHIT was conducted on each subject and analysed with the Interacoustics (EyeSeeCam) video goggles by the senior audiologist. The VOR gain for all six semicircular canals were calculated for each subject.</p><p class="abstract"><strong>Results: </strong>The mean (SD) vHIT (VOR) gain of all the 6 semicircular canals for the entire population were 1.18 (0.19). The mean of the VOR gain for each of the six semicircular canals were analysed to develop a normative guide. The mean VOR gain per decade year did not vary significantly with age (p=0.417). The correlation between age and mean VOR values was negligible (pearson’s r=0.121).</p><p class="abstract"><strong>Conclusions: </strong>We propose that our normative age-dependent data guide be used to improve the differentiation between normal and abnormal values of VOR gain in an Asian population. Our study shows that VOR gain is not associated with aging.</p>

scholarly journals Vestibular Function Measured Using the Video Head Impulse Test in Congenital Nystagmus and Vertigo: A Case Report

2021 ◽  
Vol 12 ◽  
Author(s):  
Antonio Denia-Lafuente ◽  
Belén Lombardero
Keyword(s):  
Vestibular Function ◽  
Semicircular Canals ◽  
Head Impulse Test ◽  
Congenital Nystagmus ◽  
Video Head Impulse Test ◽  
Head Impulse ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Vertical Semicircular Canals

In patients with congenital nystagmus (CN), the study of vestibular function is complicated by many factors related to the measurement of the vestibulo-ocular reflex (VOR) by means of caloric testing and the video head impulse test (vHIT), and to date no such studies have successfully employed the vHIT to evaluate vestibular function in these patients. We present a case with CN and vertigo in which peripheral vestibular function was evaluated using the vHIT system, including head impulse testing and the suppression head impulse protocol. We show that it is possible (a) to identify lateral VOR changes such as abnormalities resembling those produced by bilateral vestibular lesions, though not necessarily related to the same mechanism; (b) to identify peripheral VOR lesions of the vertical semicircular canals (SCC); and (c) to document compensation and recovery subsequent to these peripheral lesions during follow-up of patients with CN. vHIT is a useful tool that should be used to study vestibular function in patients with CN and vertigo, which could constitute a new clinical application of this technique.

scholarly journals Bilateral Vestibular Hypofunction in the Time of the Video Head Impulse Test

2019 ◽  
Vol 25 (Suppl. 1-2) ◽  
pp. 72-78
Author(s):  
Nicolás Pérez-Fernández ◽  
Laura Alvarez-Gomez ◽  
Raquel Manrique-Huarte
Keyword(s):  
Head Impulse Test ◽  
Video Head Impulse Test ◽  
Test Results ◽  
Bilateral Vestibulopathy ◽  
Similar Time ◽  
Head Impulse ◽  
Vestibular Hypofunction ◽  
Number Of Patients ◽  
Significant Difference ◽  
Bilateral Vestibular Hypofunction

Objectives: Bilateral vestibulopathy is a clinical syndrome in which laboratory testing plays a crucial diagnostic role. We aimed to establish the frequency of detection of that finding in a tertiary level hospital considering the new methods of laboratory vestibular examination nowadays in use, with respect to the conventional caloric and rotatory chair test approaches. Design: Two similar time periods (5 years) were retrospectively evaluated, and the demographic, clinical data and test results from 4,576 patients were reviewed. In the first period, the diagnosis was based on caloric and rotatory chair tests and, in the second, on the video head impulse test. Results: Of the patients included, 3.77% in the first period and 4.58% in the second met the criteria for bilateral vestibular hypofunction; there was no significant difference between both periods. Conclusions: The functional vestibular evaluation to detect bilateral deficiency makes no significant difference to the number of patients diagnosed with a bilateral vestibulopathy. New diagnostic categories probably depend not only on the availability and accessibility of complete vestibular and visual-vestibular evaluation, but also on recent advances in defining vestibular disorders. Bilateral vestibular hypofunction manifests with very different patterns. Progress in more detailed definition (clinical and laboratory) is needed, in particular when all 6 semicircular canals and both maculae are available for testing.

scholarly journals A case series shows independent vestibular labyrinthine function after major surgical trauma to the human cochlea

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Stefan K. Plontke ◽  
Torsten Rahne ◽  
Ian S. Curthoys ◽  
Bo Håkansson ◽  
Laura Fröhlich
Keyword(s):  
Case Series ◽  
Vestibular Function ◽  
Semicircular Canals ◽  
Vestibular Evoked Myogenic Potentials ◽  
Head Impulse Test ◽  
Surgical Trauma ◽  
Cochlear Function ◽  
Receptor System ◽  
Tertiary Referral Center ◽  
Significant Difference

Abstract Background The receptors for hearing and balance are housed together in the labyrinth of the inner ear and share the same fluids. Surgical damage to either receptor system was widely believed to cause certain permanent loss of the receptor function of the other. That principle, however, has been called into question because there have been anecdotal reports in individual patients of at least partial preservation of cochlear function after major surgical damage to the vestibular division and vice versa. Methods We performed specific objective vestibular function tests before and after surgical trauma (partial or subtotal cochlear removal) for treatment of intracochlear tumors in 27 consecutive patients in a tertiary referral center. Vestibular function was assessed by calorics (low-frequency response of the lateral semicircular canal), vestibulo-ocular reflex by video head impulse test (vHIT) of the three semicircular canals, cervical and ocular vestibular evoked myogenic potentials (cVEMP, saccule and oVEMP, utricle). Preoperative and postoperative distributions were compared with paired t-tests. Results Here we show that there was no significant difference between pre- and post-operative measures for all tests of the five vestibular organs, and that after major surgical cochlear trauma, the vestibular receptors continue to function independently. Conclusions These surprising observations have important implications for our understanding of the function and the surgery of the peripheral auditory and vestibular system in general and open up new possibilities for the development, construction and evaluation of neural interfaces for electrical or optical stimulation of the peripheral auditory and vestibular nervous system.

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