Higher Asymmetry Ratio and Refixation Saccades in Individuals with Motion Sickness

2018 ◽  
Vol 29 (02) ◽  
pp. 175-186 ◽  
Author(s):  
Anuj Kumar Neupane ◽  
Krithika Gururaj ◽  
Sujeet Kumar Sinha
Keyword(s):  
Motion Sickness ◽  
Dynamic Environment ◽  
Semicircular Canals ◽  
Head Impulse Test ◽  
Standard Group ◽  
Asymmetry Ratio ◽  
Vestibular Evoked Myogenic Potential ◽  
Group I ◽  
Significant Difference ◽  
Vestibulo Ocular Reflex

AbstractMotion sickness is a complex autonomic phenomenon caused by the intersensory conflict among the balancing systems, resulting in a mismatch of signals between static physical conditions of the susceptible individual exposed to dynamic environment.The present study was done to assess the sacculocollic reflex pathway and six semicircular canals in individuals susceptible to motion sickness.Standard group comparison was used.A total of 60 participants with an age range of 17–25 yr were included, where group I comprised 30 participants with motion sickness and group II comprised 30 participants without motion sickness. The Motion Sickness Susceptibility Questionnaire–Short was administered to classify the participants into groups with or without motion sickness.The cervical vestibular-evoked myogenic potential (cVEMP) test and video head impulse test (vHIT) were administered to all participants. The Shapiro–Wilk test revealed normal distribution of the data (p > 0.05). Hence a parametric independent sample t test was done to check significant difference in cVEMP and vHIT parameters between the two groups.The present study revealed no significant difference for cVEMP latencies and amplitude in individuals with motion sickness. However, significantly higher cVEMP asymmetry ratio was observed in individuals with motion sickness. Though the vestibulo-ocular reflex (VOR) gain values showed no significant difference between the two groups except for the right anterior left posterior plane, the asymmetry in VOR gain values revealed significant difference between the groups, suggesting asymmetry as a better parameter than absolute VOR gain values. Also, the presence of refixation saccades in 100% of the individuals with motion sickness accorded with various studies reported earlier with vestibular-related pathologies.Presence of higher asymmetry ratio in cVEMP and vHIT test results plus refixation saccades to stabilize the gaze in vHIT can suggest some amount of vestibular anomalies in individuals with motion sickness.

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 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.

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 Water Hyacinth (Eichhorniacrassipes) Ethanolic Extract Anti Platelet Activity

2021 ◽  
pp. 969-978
Author(s):  
Perdina Nursidika
Keyword(s):  
Cardiovascular Diseases ◽  
Blood Vessel ◽  
Effective Dose ◽  
Water Hyacinth ◽  
Ethanolic Extract ◽  
Negative Control ◽  
Control Group ◽  
Standard Group ◽  
Group I ◽  
Significant Difference

Cardiovascular diseases (CVDs) are a group of disorders of the heart and blood vessels. CVDs are responsible for 37% of deaths in Indonesia. Thrombosis is the main factor causing blood vessel clost in CVDs. Blood vessel clots then affect narrowed blood vessel. This causes strokes. The aim of this study is to determine the antithrombotic effect of water hyacinth ethanolic extract, the effective dose, and the potential to become anticoagulant agent. The water hyacinth was extracted by ethanol 96%. The extract was tested on five groups of mice, each group containing five mice. Each group was tested for fourteen days. Group I and II are fed by extract suspension with varied dose 1 mg/BW and 2 mg/BW. Group III is fed by warfarin as standard. Group IV and V are the positive and negative group, the mice were fed by NaCMC. On the 7th and 14th days, prothrombin time (PT) and activated partial thromboplastin time (aPTT) were conducted. The plasma of group 1-IV mixed with adenosine diphosphate (ADP) as inducer, except plasma of group V used for negative control, did not mixed with ADP. Data analysed by ANOVA and LSD to obtain effective dose. The results showed the difference between PTT and aPTT among the tested groups. Group I and II showed prolonged PT which is 22 and 32 seconds respectively. The control positive showed PT 9.48 seconds on day 7th and 8.22 seconds on day 14th. LSD analysis showed that there is the significant difference between positive control and the other groups. It showed platelet aggregation performed due to the addition of ADP as inducer. There was a significant difference between dose 2 and the negative control group, and there is no significant difference of dose 1. In conclusion, water hyacinth has the antithrombotic activity, the effective dose is 1 mg/BW, and it potential to further developed as anticoagulant agent.   Keywords: antiplatelet, cardiovascular diseases, water hyacinth.

scholarly journals Acute Vertigo in a Patient with Long-Term Organic Solvent Exposure: Importance of a Comprehensive Audio-Vestibular Test Battery

2020 ◽  
Vol 31 (05) ◽  
pp. 363-368
Author(s):  
Maxime Maheu ◽  
François Champoux ◽  
Adrian Fuente
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Vestibular System ◽  
Semicircular Canals ◽  
Vestibular Evoked Myogenic Potentials ◽  
Head Impulse Test ◽  
Solvent Exposure ◽  
Vestibular Evoked Myogenic Potential ◽  
Vestibular Tests ◽  
Organic Solvent Exposure

Abstract Background Ototoxicity induced by organic solvents has been identified in several groups of workers. Little is known, however, about the effects of organic solvents on the vestibular system. Purpose The aim of the study was to comprehensively assess the vestibular system and auditory functions in a worker exposed to organic solvents. Research Design Both behavioral and physiological auditory and vestibular evaluations were performed. Results No auditory-related findings associated with solvent exposure were found. The vestibulo-ocular reflex gain was abnormal for all semicircular canals with significant catch-up saccades, as measured by the video head impulse test. The cervical vestibular evoked myogenic potentials was absent in the right ear and small but replicable in the left ear. Ocular vestibular evoked myogenic potential were bilaterally absent. Conclusions The results suggest a case of vestibulotoxicity induced by a long history of organic solvent exposure. We suggest that solvent-exposed individuals should be evaluated with a comprehensive battery of auditory and vestibular tests.

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.

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.

The relationship between functional head impulse test and age in healthy individuals

2021 ◽  
pp. 1-13
Author(s):  
Tuğba Emekci ◽  
Hatice Seyra Erbek
Keyword(s):  
Semicircular Canals ◽  
Head Impulse Test ◽  
Healthy Population ◽  
Healthy Individuals ◽  
Head Impulse ◽  
Vestibular Diseases ◽  
Functional Head ◽  
Functional Perspective ◽  
Study Results ◽  
Vestibulo Ocular Reflex

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.

scholarly journals Evaluation of the effects of Covid-19 on cochleovestibular system with audiovestibular tests

2022 ◽  
pp. 014556132110699
Author(s):  
Kazım Bozdemir ◽  
Elif Ersoy Çallıoğlu ◽  
Yüce İslamoğlu ◽  
Mehmet Kadir Ercan ◽  
Fatma Eser ◽  
...  
Keyword(s):  
Otoacoustic Emissions ◽  
Pure Tone ◽  
Pure Tone Audiometry ◽  
Semicircular Canals ◽  
Outer Hair Cells ◽  
Head Impulse Test ◽  
Control Group ◽  
Caloric Test ◽  
Distortion Product ◽  
Significant Difference

Purpose The purpose of the present study was to investigate the effects of COVID-19 on audiovestibular system with Transiently Evoked Distortion Otoacoustic Emissions (TOAE), Distortion Product Otoacoustic Emissions (DPOAE), video head impulse test (vHIT) and caloric test. Methods Audiovestibular findings of 24 patients with moderate/severe COVID-19 and 24 healthy controls were compared using pure tone audiometry, tympanometry, TOAE, DPOAE, caloric test, and vHIT. Results On audiometry, the pure tone averages of the COVID-19 patients were higher than the controls ( P = .038). The TEOAE amplitudes at 4000 and 5000 Hz ( P = .006 and P < .01), and DPOAE amplitudes at 3000, 6000, and 8000 Hz ( P < .001, P = .003 and P < .001) were significantly lower in COVID-19 patients compared to the controls. On vestibular tests, there was no significant difference between the caloric test results of the patients and the controls ( P > .05). On vHIT testing, amplitudes of right semicircular canal was found to be significantly lower in COVID-19 group compared to the control group ( P = .008). Conclusion COVID-19 may affect inner ear functions causing a subtle damage in the outer hair cells and lateral semicircular canals. It must be kept in mind that COVID-19 may cause cochleovestibular problems.

Evaluation of Vertical Semicircular Canal Function in Patients With Vestibular Schwannoma

2018 ◽  
Vol 128 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Keishi Fujiwara ◽  
Hiroko Yanagi ◽  
Shinya Morita ◽  
Kimiko Hoshino ◽  
Atsushi Fukuda ◽  
...  
Keyword(s):  
Vestibular Schwannoma ◽  
Semicircular Canal ◽  
Vestibular Function ◽  
Semicircular Canals ◽  
Vestibular Nerve ◽  
Head Impulse Test ◽  
Posterior Semicircular Canal ◽  
Vestibulo Ocular Reflex ◽  
Anterior Semicircular Canal ◽  
Vertical Semicircular Canal

Objectives: The aim of this study was to investigate vertical semicircular canal function in patients with vestibular schwannoma (VS) by video head impulse test (vHIT). Methods: Fifteen patients with VS who had not received any treatment, including surgery or stereotactic radiotherapy, before vHIT examination were enrolled. Vestibulo-ocular reflex gain and catch-up saccade in vHIT were evaluated. Results: Dysfunction of anterior and posterior semicircular canals was detected by vHIT in 26.7% and 60.0%, respectively. Six patients (40.0%) demonstrated abnormalities referable to both vestibular nerve divisions. Abnormalities referable to the superior vestibular nerve were identified in 3 patients (20.0%), while 3 patients (20.0%) demonstrated a pattern indicative of inferior vestibular nerve involvement. Anterior semicircular canal vHIT produced fewer abnormalities than did either horizontal or posterior semicircular canal vHIT. Conclusions: Dysfunction of the semicircular canals, including the vertical canals, in patients with VS was detected by vHIT. The anterior semicircular canal was less frequently involved than the horizontal or posterior semicircular canal. The examination of the vertical canals by vHIT is useful in the evaluation of vestibular function in patients with VS.

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