ABSTRACT
Acute labyrinthine infarction due to vertebrobasilar insufficiency results in acute vestibular and cochlear functional loss. It is very difficult to differentiate acute labyrinthine infarction from acute viral labyrinthitis, vestibulocochlear neuritis and sudden sensorineural hearing loss. Because its definite diagnosis criteria has not been yet established and confirmative diagnosis tool is limited, the diagnosis and appropriate treatment is more difficult. It is often misdiagnosed as a peripheral vestibular disorder because its clinical symptom is usually a form of dizzy attack with hearing impairment. We experienced a case of acute labyrinthine infarction due to vertebrobasilar insufficiency. We differentiated it from acute labyrinthitis and vestibulocochlear neuritis using ENG and diagnosed it by means of periodic ENG follow-up. Confirmative diagnosis was made by means of MR angiography. MR angiography shows non-opacification of right vertebral artery and focal stenosis of right basilar artery. We treated this patient with 500,000 unit of urokinase per day for 5 days and observed recovery of impaired vestibular and cochlear function.