Age adjusted normative data for Video Head Impulse Test in healthy subjects

Purpose: This study aims to assess the effect of age in vestibulo-ocular reflex (VOR) gain measured by Video Head Impulse Test (VHIT) and to present normative data of VOR gain, median gain at 40, 60, 80 and 0-100 ms, and gain asymmetry according to decades of life in healthy subjects. Material and methods: A total of 132 subjects with no previous history of vestibular disorders were enrolled to assess VOR gain by employing VHIT. The test was performed in the X-axis evaluating both horizontal semicircular canals (HSC). The same right-handed operator performed the test in all subjects. Results: The mean VOR gain was higher in the right ear (0.99 +/- 0.09) compared to the left ear (0.97 +/- 0.08) (p = 0.001). Median gain at 60 ms was 0.92 +/- 0.12 in the right HSC and 0.93 +/- 0.10 for the left HSC, without significant difference (p = 0.94). A significant decrease of VOR gain occurred with increasing age in the right ear (r = 0.21, p = 0.01). Median gain at 60 ms decreased significantly as age increased in both HSC (right r = 0.17, p = 0.04; left r = 0.23, p = 0.006). No significant differences in VOR gain values were observed when the sample was stratified by age according to the analysis of variance. Conclusions: A slight but significant decrease in VOR function was observed as age increased for gain and median gain at 60 ms. Larger studies, including patients with central and peripheral vestibular disorders, are needed to assess the clinical implication of this effect when evaluating patients with vestibular disorders.