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.
Keywords
video head impulse test - interexaminer variability - vestibulo-ocular reflex gain
