Isolated dizziness in vertebrobasilar insufficiency: Clinical features, angiography, and follow-up.

Dizziness is the most common manifestation of vertebrobasilar insufficiency (VBI) and may occur as an isolated symptom in some patients. In order to determine if there is a characteristic pattern of vascular occlusion associated with this symptom, we reviewed the cerebral angiograms of seven patients (average age, 62 years) who presented with isolated episodes of dizziness. Six of seven had atherosclerotic occlusion of the vertebrobasilar junction between the takeoff of the posterior and anterior inferior cerebellar arteries. The other patient had basilar dolichoectasia without luminal narrowing. Our data suggest that isolated episodes of dizziness with VBI probably result from transient ischemia in territories supplied by the anterior inferior cerebellar artery. Anticoagulation stopped the attacks in six of seven patients who had recurrent symptoms despite aspirin therapy. Overall the prognosis was good.