METHODS: Sixty healthy adult subjects aged 22-76-year-old (mean ± standard deviation=47.27 ± 18.29) participated in the head impulse paradigm and suppression head impulse paradigm using the video head impulse test. The Head impulse paradigm was used to assess all 6 semicircular canals, while suppression head impulse paradigm measured only the horizontal canals. Twenty subjects aged 22-40-year-old (25.25 ± 4.9) underwent a second session for the test-retest reliability.

RESULTS: There were good test-retest reliability for both measures (right horizontal head impulse paradigm, intraclass correlation coefficient=0.80; left horizontal head impulse paradigm, intraclass correlation coefficient=0.77; right anterior head impulse paradigm, intraclass correlation coefficient=0.86; left anterior head impulse paradigm, intraclass correlation coefficient=0.78; right posterior head impulse paradigm, intraclass correlation coefficient=0.78; left posterior head impulse paradigm, intraclass correlation coefficient=0.75; right horizontal suppression head impulse paradigm, intraclass correlation coefficient=0.76; left horizontal suppression head impulse paradigm, intraclass correlation coefficient=0.79). The test-retest reliability for suppression head impulse paradigmanti-compensatory saccade latency and amplitude were moderate (right latency, intraclass correlation coefficient=0.61; left latency, intraclass correlation coefficient=0.69; right amplitude, intraclass correlation coefficient=0.69; left amplitude, intraclass correlation coefficient=0.58). There were no significant effects of age on head impulse paradigm and suppression head impulse paradigm vestibulo-ocular reflex gain values and suppression head impulse paradigmsaccade latency. However, the saccade amplitude became smaller with increasing age, P < .001. The horizontal suppression head impulse paradigm vestibuloocular reflex gain values were significantly lower than the head impulse paradigm for both sides (right, P = .004; left, P = .004).