Abstract
It is speculated that tinnitus is caused by vertebrobasilar insufficiency in a considerable number of patients. However, clinical findings to diagnose circulatory disturbance in the vertebrobasilar system remain to be clarified. Six cases of tinnitus were reported, where vertebrobasilar insufficiency was considered to be an etiology of tinnitus on the basis of clinical findings such as asymptomatic cerebral infarction, past history of cerebral infarction, nystagmus suggesting central disturbance and marked changes in blood pressure. Tinnitus disappeared after therapy for cerebral circulatory disorder in all six patients. We confirmed that binaural lowfrequency hearing loss of nearly equal extent which was detected by audiometry on the first visit, improved or tended to improve after therapy. Low-frequency hearing loss was considered to be an important audiometric indication of circulation disturbance in the vertebrobasilar system, although it was often overlooked in the clinical setting.
