scholarly journals Functional Testing of all Six Semicircular Canals with Video Head Impulse Test Systems

Author(s):  
Dan D. Hougaard ◽  
Emil R. Abrahamsen
Author(s):  
Fahimeh Esmaeili ◽  
Mansoureh Adel Ghahraman ◽  
Reza Hoseinabadi ◽  
Reza Hoseinabadi ◽  
Shohreh Jalaie ◽  
...  

Background and Aim: In unilateral sudden sensorineural hearing loss (SSNHL), the ves­tibular system may be involved in addition to the auditory system. Several hearing assess­ments have shown that the disease course and the patient's improvement, at least two step of vestibular assessments can help in better control of the patient's balance function. The aim of this study was to evaluate the results of cervical ves­tibular evoked myogenic potentials (cVEMP) and video head impulse test (vHIT) used for assessment of saccule and semicircular canals before and after steroid therapy. Methods: Twenty three patients with SSNHL were evaluated for auditory and vestibular func­tion before and after steroid therapy. The results of cVEMP and vHIT were compared between intact and impaired ears and between pretest/posttest stages before and after treatment. Results: For 26.08% of patients, the cVEMP response was absent in the affected ear, but after treatment it was reported for all patients. There was a significant difference in vestibulo-ocular reflex (VOR) gain for both posterior and ante­rior semicircular canals of affected ear before and after treatment, but it was not significantly different after treatment as VOR gain increased. Conclusion: Dysfunction of nervous and vesti­bular systems in SSNHL is possible. Steroid therapy can improve the vestibular function and hearing of these patients. Therefore, vestibular evaluation can be used to determine the extent of lesions in SSNHL.   Keywords: Unilateral sudden sensorineural hearing loss; vestibular evoked myogenic potentials; saccule; semicircular canals; video head impulse test


Author(s):  
Homa Zarrinkoob ◽  
Hadi Behzad ◽  
Seyed Mehdi Tabatabaee

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.


2021 ◽  
Vol 79 (7) ◽  
pp. 571-578
Author(s):  
Lilian Felipe

ABSTRACT Background: The video head impulse test (vHIT) is a recent technique for functional evaluation of semicircular canals (SSCs). The vHIT examines eye movements at high frequencies of stimulation and provides an objective assessment of the functioning of the high-frequency domain of the vestibular system. Objective: To describe the results from vHIT performed using two systems. Methods: All subjects were evaluated through an audiological and otoneurological battery of tests and were diagnosed as normal or abnormal by an otorhinolaryngologist. The results from two systems: 1. ICS Impulse (Otometrics/Natus, Denmark) and 2. EyeSeeCam (InterAcoustics, Denmark) were recorded. The same operator delivered every impulse to every subject. The head impulses were performed while the operator was standing behind the subject, using both hands on the top of the subject’s head, well away from the goggles strap and forehead skin. Two calibrations were completed in each system, prior to beginning the test. Results: Test parameters were recorded through both systems for healthy subjects with no history or complaint of any vestibular disorder (N = 12; M/F = 5/7; age 35.1 ± 13.5 y) and for pathological subjects with a diagnosis of unilateral or bilateral vestibular disorder (N = 15; M/F = 7/8; age 53.4 ± 16.7 y). Conclusions: The vHIT is an important tool for otoneurological complementary evaluation. Both systems are reliable for vestibular disorders. The EyeSeeCam seems to reject fewer data and provides more information to include in diagnostics. Because of the small sample, there is a need for further in-depth comparison of both systems.


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.


2019 ◽  
Vol 40 (01) ◽  
pp. 033-039
Author(s):  
Ian S. Curthoys ◽  
Ann M. Burgess ◽  
Leonardo Manzari

AbstractRecent advances in vestibular testing now permit functional testing of all peripheral vestibular sense organs (all three semicircular canals, utricle, and saccule). This makes it possible to identify patients with isolated dysfunction of the utricle or saccule, even though parallel pathways for vestibular information are ultimately integrated centrally. Selective, isolated unilateral loss of utricular function as measured by ocular vestibular-evoked myogenic potentials (VEMPs) has been observed in patients with normal semicircular canal function as measured by the video head impulse test of all six semicircular canals, and normal bilateral saccular function as determined by symmetrical cervical VEMPs. How these patients present clinically and how they recover is discussed and contrasted with acute vestibular neuritis. In some patients, the unilateral loss of otolith organ (utricle or saccule) function persists and yet the patient recovers functionally to their usual lifestyle. Until the testing of all peripheral vestibular sense organs is routine, the frequency of isolated loss of otolith function cannot be gauged.


2014 ◽  
Vol 73 (1) ◽  
pp. 22-31
Author(s):  
Susumu Shindo ◽  
Kazuki Sugizaki ◽  
Akinori Itoh ◽  
Osamu Shibasaki ◽  
Masahiro Mizuno ◽  
...  

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