SURVIVAL WITH BASILAR ARTERY-OCCLUSION

Basilar artery (BA) occlusion is generally believed to have a high mortality. A favorable outcome is rarely reported, A consecutive series of 20 survivors with angiographically proven symptomatic BA occlusion not treated with thrombolysis or selected for outcome were analyzed for clinical presentation and neuroradiologic features to find outcome predictors. Long-term functional outcome (Rankin scale) was good in 12 (60%), moderate in 4 (20%), and poor in 4 (20%) patients who had complete mid-segmental BA occlusions and bilateral large pontine infarcts. Prominent retrograde collateral supply from the carotids and/or anterograde from the cerebellar arteries was present in all patients with adequate angiographic studies (n = 18). BA occlusion was proximal in 12, mid-segmental in 7, and distal in 1 patient. Stroke etiology was considered atherothrombotic in 14 (70%), embolic in 2 (10%), and related to migraine in 4 (20%). Clinical outcome following BA occlusion is more heterogenous than usually presumed and influenced by the temporal course, length of BA occlusion, availability of collateral circulation, and extent of brainstem infarction. The etiology of benign BA occlusion is mostly local thrombosis.