A 50-year-old woman presents with sudden onset severe vertigo, nausea, horizontal nystagmus (fast phase toward the left), past-pointing to the right, and positive Romberg (falls to right). There is no hearing loss. Which is the MOST likely diagnosis and the expected caloric test finding?

• A Left vestibular neuritis; left canal paresis on caloric testing
• B Right labyrinthitis; left canal paresis on caloric testing
• C Posterior circulation stroke; normal bithermal caloric test
• D Right vestibular neuritis; right canal paresis on caloric testing ✓

Explanation

Vestibular neuritis presents with acute severe vertigo without hearing loss (distinguishing it from labyrinthitis which includes SNHL). Nystagmus fast phase beats AWAY from the lesioned (hypoactive) side — here fast phase to the left means the lesion is on the right. Past-pointing and Romberg falling are toward the lesion side (right). Caloric testing will show right canal paresis (reduced or absent response to caloric stimulation of the right ear) confirming right-sided vestibular hypofunction. The aetiology is presumed viral reactivation of HSV-1 in the vestibular nerve.

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.