Video head impulse test (vHIT) is abnormal with catch-up saccades noted for horizontal head impulses to the RIGHT. Which structure is most likely dysfunctional?

• A Left horizontal semicircular canal via left vestibular nerve
• B Right posterior semicircular canal
• C Right horizontal semicircular canal via right vestibular nerve ✓
• D Left utricle

Explanation

In the video head impulse test (vHIT), catch-up saccades during horizontal head thrust to the right indicate failure of the VOR to generate adequate compensatory eye movement toward the left during the rightward impulse. This implicates the right horizontal semicircular canal/right vestibular nerve, since the right horizontal canal is maximally stimulated by rightward head rotation. The brain compensates with catch-up saccades because the VOR gain is insufficient. This is the principal clinical test for acute vestibular neuritis and the affected side corresponds to the direction of the impulse showing the catch-up saccade.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.