On video head impulse test (vHIT), a patient shows normal gain but corrective saccades (covert saccades) after rapid head rotation toward the left. This finding indicates:

• A Normal left vestibulo-ocular reflex
• B Left superior semicircular canal dysfunction
• C Central pathway lesion affecting the VOR arc
• D Subclinical left lateral semicircular canal hypofunction with compensatory mechanism ✓

Explanation

In vHIT, covert saccades occurring during the head impulse (before the head stops) with apparently normal gain indicate a mild or well-compensated vestibular deficit. The canal affected is the one toward which the head is rotated when the saccade appears; left head rotation = left lateral canal. The covert saccades represent a central compensatory strategy when the VOR is insufficient. Central lesions typically show normal vHIT despite clinical dizziness.

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.