A 46-year-old man describes very brief spinning sensations lasting a few seconds, occurring many times daily and provoked by turning his head to the left. Examination and audiometry are unremarkable. MRI shows a vascular loop impinging on the vestibulocochlear nerve at the cerebellopontine angle. He improves dramatically with carbamazepine. The most likely diagnosis is:

• A Vertebrobasilar insufficiency
• B Superior semicircular canal dehiscence syndrome
• C Recurrent vestibular neuritis
• D Microvascular compression of the eighth nerve causing vestibular paroxysmia ✓

Explanation

Vestibular paroxysmia consists of numerous brief attacks of vertigo lasting seconds to about a minute, triggered by changes in head position, caused by neurovascular compression of the eighth nerve root entry zone. D dramatic response to carbamazepine or oxcarbazepine supports both diagnosis and neurogenic hyperexcitability as the mechanism. SSCD produces sound- or pressure-induced vertigo with conductive findings, while vertebrobasilar insufficiency lasts minutes and is not carbamazepine responsive.

Reference: Dhingra's Diseases of Ear, Nose and Throat, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.