Vestibular neuritis affects which part of the vestibular system most commonly, and which diagnostic test can help distinguish it from acute cerebellar stroke?

• A Saccule; caloric testing
• B Posterior semicircular canal; MRI with diffusion-weighted imaging alone
• C Superior vestibular nerve and labyrinth; HINTS examination (Head-Impulse, Nystagmus, Test of Skew) ✓
• D Cochlear nerve; pure tone audiogram

Explanation

Vestibular neuritis predominantly affects the superior division of the vestibular nerve (supplying the superior and horizontal semicircular canals and the utricle), presumed due to viral reactivation (HSV-1) in Scarpa's ganglion. It causes acute onset vertigo with horizontal-torsional spontaneous nystagmus. The HINTS examination (positive Head Impulse test — catch-up saccade, uni-directional nystagmus, absent test of skew) has been shown to be more sensitive than early MRI-DWI for distinguishing peripheral causes from posterior fossa stroke. A normal head impulse test + direction-changing nystagmus + vertical skew deviation = central cause.

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.