During the head impulse test, what does a catch-up saccade indicate?

• A. Normal VOR gain with fixation
• B. Central vestibular lesion
• C. Peripheral vestibular hypofunction with reduced VOR gain
• D. No corrective response

Answer: (C)

The head impulse test checks the vestibulo-ocular reflex, which normally keeps your gaze stable by producing a rapid eye movement that matches and counteracts a quick head turn. When the VOR is working well, the eyes stay on target without needing extra movement. If one side has peripheral vestibular hypofunction, that VOR gain is reduced on that side, so when you quickly turn the head toward the affected side the eyes can’t keep up. A fast corrective eye movement, a catch-up saccade, then brings the gaze back to the target. This pattern specifically points to a peripheral vestibular deficit with reduced VOR gain, rather than a normal response or a central lesion.