Abstract
Magnetic resonance imaging showed impingement of a dolichoectatic vertebral artery on the medulla in 8 patients with auditory and/or vestibular symptoms. Unilateral auditory and/or vestibular symptoms on the same side as the impinged parts were recognized in 5 patients, who manifested no pyramidal or other central nervous signs. These unilateral lesions were speculated to be due to neurovascular compression of the 8th cranial nerve. Two patients revealed downbeat nystagmus without any other cen-tral nervous signs, which might have arisen from an ischemic brain stem lesion. One other patient with brain atrophy and cerebellar sign also showed downbeat nystagmus which might have been due to cerebellar atrophy.
Impingement of the vertebral artery on the medulla may not induce unilateral auditory and/or vestibular symptoms, but may represent a risk factor of circulatory disturbance in the brain stem.
