Abstract
A 75-year-old male was admitted to our hospital because of dizziness and gait disturbance. Angiography revealed complete obstruction of the left vertebral artery and severe stenosis of the right vertebral artery. The posterior circulation was not sufficiently filled by either of the carotid arteries. Caloric tests indicated left canal paresis. Smooth pursuit was disturbed and ocular dysmetria was found in saccade. OKN showed that pursuit eye movement was severely disturbed and nystagmus waves were irregular. We speculated that these disturbances were mainly of the left vestibular nuclei and the cerebellar vermis and were caused by insufficiency of the posterior circulation. Because conservative therapy was not effective, superficial temporal artery-superior cerebellar artery (STA-SCA) anastomosis was carried out on the right side. Dizziness disappeared and gait disturbance was improved. Pursuit eye movement towards the left was markedly improved, and ocular dysmetria disappeared.
