Circulatory failure is considered to be one of the causes of sudden deafness. We describe here 4 patients with hearing impairment associated with lesions in the vertebrobasilar artery system.
Patient No. 1 had bilateral sudden deafness on two occasions—a very rare occurrence. Severe bilateral vertebroarterial stenosis was demonstrated by vertebral angiography. Patient No. 2 experienced sudden deafness on the left. A defect of the left vertebral artery was found on vertebral angiography. Patient No. 3 had right sudden deafness accompanied by facial paralysis. CT scan revealed cerebellar infarction on that side; the cause of deafness was defined as a vascular accident involving the right inferior anterior cerebellar artery. Patient No. 4 complained mainly of dizziness, tinnitus and deafness. Although hearing impairment was evaluated as mild by pure-tone audiometry, there was an abnormalitiy of ABR. Hemorrhagic infarction was found in the right cerebellum by CT scan, so vascular accident involving the right superior cerebellar artery was diagnosed.
In the past we have described forms of hearing impairment due to cerebrovascular disorders. Our present findings suggest that as otologists we should examine not only the labyrinthine artery, but also its upstream arteries, such as the inferior anterior cerebellar artery and the vertebro-basilar artery system, whenever we encounter sudden deafness in daily practice and suspect a vascular disorder to be the cause. In other words, we should always keep in mind the possibility of concomitant central nervous system lesions.