ANTERIOR SPINAL ARTERY COLLATERAL FLOW IN VERTEBROBASILAR OCCLUSIVE DISEASE

A 49-year-old man was referred for an episode of regressive hemiparesi s, caused by proven brainstem infarction. Five weeks later, he started a series of posterior circulation transient ischemic attacks (TIAs) a nd angiography revealed left intracranial vertebral artery occlusion w ith contralateral severe vertebral artery stenosis and a significant c ollateral flow from the anterior spinal artery to the basilar artey. T he TIAs stopped immediately after beginning of treatment with aspirin and heparin, and with this the patient has been asymptomatic for 4 yea rs. This rare collateral pathway seems to be efficient in preventing h emodynamically induced ischemia in the posterior circulation, while an tiaggregation and anticoagulation prevent further artery-to-artery emb olism and may help to keep the collateral open.