Effect of Aging and Direction of Impulse in Suppression Head Impulse Test.

Abstract

To identify differences in the vestibulo-ocular reflex (VOR) gain value and the peak saccade velocity in the suppression video head impulse test paradigms according to the age of the subject and the direction of the impulse. Retrospective chart analysis. Tertiary referral hospital. Between October 2017 and May 2019, we enrolled subjects who had previous histories of dizziness but no dizziness over the last 1 month. We conducted cervical vestibular-evoked myogenic potential and caloric tests, as well as video head impulse tests. We excluded the subjects who had abnormal cervical vestibular-evoked myogenic potential results (asymmetry ratio of greater than 30%) and abnormal caloric test results (caloric paresis of greater than 25%). We included 647 subjects aged 10 to 87 years. The mean VOR gain and peak saccade velocity were maintained in subjects less than 70 years old (VOR gain, 0.991 ± 0.08, peak saccade velocity, 348.47 ± 142.32). However, the decreases in VOR gain and peak saccade velocity were significant in subjects over 70 years old (VOR gain, 0.928 ± 0.09, peak saccade velocity, 315.51 ± 0.09; p < 0.001). The mean VOR gain of the rightward impulse (1.00 ± 0.09) was higher than the leftward impulse (0.96 ± 0.08, p < 0.001). Both the VOR gain and peak saccade velocity of suppression video head impulse test paradigms declined with increasing age over 70 years. In addition, the VOR gain of the rightward impulse was higher than the leftward impulse in the right-eye recordings.