Vestibular paroxysmia caused by contralateral tortuous vertebral artery: A case report.

RATIONALE Vestibular paroxysmia (VP) is characterized by spontaneous, recurrent, short, paroxysmal attacks of vertigo with or without tinnitus. PATIENT CONCERNS We report a case of paroxysmal recurrent vertigo accompanying clicking tinnitus on the left side in a 61-year-old patient. He had undergone microvascular decompression to treat the left-side hemifacial spasm 6 years prior. The patient first developed vertigo attacks about 3 years after microvascular decompression, and the attacks increased in frequency over the last 4 months. Video-nystagmography revealed a background right-beating nystagmus which was reversed every 55 seconds, to left-beating nystagmus for 17 seconds. DIAGNOSIS Brain magnetic resonance imaging and angiography demonstrated a compression of the cisternal segment of the left vestibulocochlear nerve between the tortuous right vertebral artery and the posterior wall of the left porus acusticus internus. INTERVENTIONS AND OUTCOMES Under the diagnosis of VP, 300 mg oxcarbazepine was administered daily, which relieved the symptoms dramatically. LESSON The neurovascular cross-compression of the vestibulocochlear nerve by the contralateral vertebral artery tortuosity can cause VP. Periodic paroxysms of right-beating nystagmus accompanying the left-side tinnitus during vertigo attacks in our patient can be explained by secondary central hyperactivity in both vestibular and cochlear nuclei following long-standing neurovascular cross-compression.