scholarly journals Normal Saccadic Responses Using Video Head Impulse Test In Healthy Young Adults

2018 ◽  
Vol 17 (1) ◽  
Author(s):  
Nurul Amira Omar ◽  
Saiful Adli bin Jamaluddin

Introduction: Vertigo and dizziness are common symptoms reported in audiology and ENT clinics. One of the objective assessments includes the video head impulse test (vHIT) where gain & amp; velocity responses of eye movements relative to the head movements are recorded using an infrared camera. Materials and Methods: Thirty normal hearing subjects age between 18 to 25 years old participated in this study. Exclusion factors include those with the history of head or neck injury and vertigo. At least ten lateral, left anterior right posterior (LARP), and right anterior left posterior (RALP) responses were recorded for each participant by making small unpredictable head movements. Results: The average velocity gain for lateral responses at 40 ms, 60 ms and 80 ms were 1.05 ± 0.003, 1.03 ± 0.002 and 1.01 ± 0.003 respectively. The LARP and RALP average velocity regression were 1.01 ± 0.24 for left anterior and 1.05 ± 0.25 for right posterior, 1.08±0.31 for right anterior and 1.12 ± 0.30 for left posterior. One sample T-test was conducted to compare lateral responses to a previous study by Mossman et al. 2015. There were significant differences in velocity gain at 60 ms and 80 ms where, t (59) = 5.56, p < 0.01 and t (59) = 2.86, p < 0.01, respectively. Conclusion: This indicates the importance of establishing norms for clinics as various factors could affect the results such as techniques used and equipment differences. A follow-up study on subjects with vestibular disorders is required to validate this data as a normative reference.

2020 ◽  
Vol 18 (3) ◽  
Author(s):  
Jamaluddin SA ◽  
Omar NA

Introduction: Many new objective tests to assess the function of specific structures of the vestibular organ are currently adopted in vestibular clinics. One of the objective assessments include the video head impulse test (vHIT) where gain & velocity responses of eye relative to the head movements are recorded using an infrared camera. Methods: Thirty normal hearing subjects age between 18 to 25 years old participated in this study. At least ten Lateral, Left Anterior Right Posterior (LARP), and Right Anterior Left Posterior (RALP) responses were recorded for each participant by making small and rapid unpredictable head movements. Results: The average velocity gain for Lateral responses at 40 ms, 60 ms and 80 ms were 1.05 ± 0.003, 1.03 ± 0.002 and 1.01 ± 0.003 respectively. The LARP average velocity regression were 1.01 ± 0.24 for Left Anterior and 1.05 ± 0.25 for Right Posterior, with an average gain asymmetry of 5.13%. The RALP average velocity regression were 1.08 ± 0.31 for Right Anterior and 1.12 ± 0.30 for Left Posterior, with an average gain asymmetry of 5.87%. One sample T-test were conducted to compare Lateral responses to a previous study by Mossman et al. (2015) where significant differences in velocity gain at 60 ms and 80 ms between studies were found where, t (59) = 5.56, p <0.01 and t (59) = 2.86, p >< 0.01 respectively. Conclusion: This indicates the importance of establishing on-site norms for every clinical settings as techniques used and equipment differences could affect the results.


2018 ◽  
Vol 23 (5) ◽  
pp. 285-289 ◽  
Author(s):  
Patricia Castro ◽  
Sara Sena Esteves ◽  
Florencia Lerchundi ◽  
David Buckwell ◽  
Michael A. Gresty ◽  
...  

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.


2020 ◽  
Vol 31 (08) ◽  
pp. 613-619
Author(s):  
Başak Mutlu ◽  
Sıdıka Cesur ◽  
Merve Torun Topçu ◽  
Cennet Reyyan Geçici ◽  
Öyküm Esra Aşkın ◽  
...  

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.


2018 ◽  
Vol 159 (2) ◽  
pp. 347-353 ◽  
Author(s):  
Chan Joo Yang ◽  
Eun Hye Cha ◽  
Jun Woo Park ◽  
Byung Chul Kang ◽  
Myung Hoon Yoo ◽  
...  

Objectives We investigated changes in video head impulse test (vHIT) gains and corrective saccades (CSs) at the acute and follow-up stages of vestibular neuritis to assess the diagnostic value of vHIT. Study Design Case series with chart review. Setting Tertiary medical center. Subjects and Methods Sixty-three patients with vestibular neuritis who underwent vHIT at an initial presentation and an approximately 1-month follow-up were included. vHIT gains, gain asymmetry (GA), peak velocities of CS, and interaural difference of CS (CSD) were analyzed. Results Mean vHIT gains increased significantly from the acute stage to the follow-up exam. The mean GA, peak velocities of CS, and CSD had decreased significantly at the follow-up. The incidence of CSs was also significantly decreased at the follow-up. The abnormal rate (87%) considering both gain and CS value was significantly higher than that (62%) considering vHIT gain only at the follow-up, although the abnormal rates did not differ at the acute stage (97% vs 87%). Conclusion The abnormal rates based on both vHIT gains and CS measurements are similar at the acute stage of VN but are considerably higher at the follow-up stage compared with the abnormal rates based on vHIT gains alone. It is thus advisable to check both CS and vHIT gain while performing vHIT to detect vestibular hypofunction.


2021 ◽  
Vol 12 ◽  
Author(s):  
Antonio Denia-Lafuente ◽  
Belén Lombardero

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.


2021 ◽  
pp. 1-9
Author(s):  
Kim E. Hawkins ◽  
Elodie Chiarovano ◽  
Serene S. Paul ◽  
Ann M Burgess ◽  
Hamish G. MacDougall ◽  
...  

BACKGROUND: Parkinson’s disease (PD) is a common multi-system neurodegenerative disorder with possible vestibular system dysfunction, but prior vestibular function test findings are equivocal. OBJECTIVE: To report and compare vestibulo-ocular reflex (VOR) gain as measured by the video head impulse test (vHIT) in participants with PD, including tremor dominant and postural instability/gait dysfunction phenotypes, with healthy controls (HC). METHODS: Forty participants with PD and 40 age- and gender-matched HC had their vestibular function assessed. Lateral and vertical semicircular canal VOR gains were measured with vHIT. VOR canal gains between PD participants and HC were compared with independent samples t-tests. Two distinct PD phenotypes were compared to HC using Tukey’s ANOVA. The relationship of VOR gain with PD duration, phenotype, severity and age were investigated using logistic regression. RESULTS: There were no significant differences between groups in vHIT VOR gain for lateral or vertical canals. There was no evidence of an effect of PD severity, phenotype or age on VOR gains in the PD group. CONCLUSION: The impulsive angular VOR pathways are not significantly affected by the pathophysiological changes associated with mild to moderate PD.


2020 ◽  
Vol 30 (6) ◽  
pp. 393-399
Author(s):  
Yahav Oron ◽  
Ophir Handzel ◽  
Zohar Habot-Wilner ◽  
Keren Regev ◽  
Arnon Karni ◽  
...  

BACKGROUND: Susac syndrome (retino-cochleo-cerebral vasculopathy, SuS) is an autoimmune endotheliopathy characterized by the clinical triad of encephalopathy, branch retinal artery occlusions and sensorineural hearing loss. In contrast to data regarding auditory function, data measuring vestibular function is sparse and the cervical vestibular-evoked myogenic potentials (cVEMPs). OBJECTIVE: To determine whether the video head impulse test (vHIT) can serve as a confirmatory assessment of vestibulocochlear dysfunction in cases of suspected SuS. METHODS: Seven patients diagnosed with SuS underwent pure tone audiometry, a word recognition test, cVEMPs and the vHIT. RESULTS: Five patients were diagnosed with definite SuS, and two with probable SuS. Two patients were asymptomatic for hearing loss or tinnitus, and no sensorineural hearing loss was detected by audiograms. Four patients complained of tinnitus, and three patients reported experiencing vertigo. Three patients had abnormal cVEMPs results. All seven patients’ vHIT results were normal, except for patient #2, who was one of the three who complained of vertigo. The calculated gain of her left anterior semicircular canal was 0.5, without saccades. CONCLUSIONS: This is the first study to describe the results of the vHIT and cVEMPs among a group of patients with SuS. The results suggest that the vHIT should not be the only exam used to assess the function of the vestibular system of SuS patients.


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