DISSECTIONS OF THE BASILAR ARTERY

Purpose: To describe clinical, radiological and pathological-anatomica l findings of basilar artery dissections. Methods: During a period of three years (1994-1996) we observed 4 patients with dissections of the basilar artery, proven by angiography. Angiograms, MRI (n = 2) and au topsy results (n = 1) of these patients were correlated with clinical symptoms and long-term follow-up. Results: In three patients the disse ction was confined into the basilar artery. Three patients with verteb robasilar ischaemia showed irregularities of the vessel wall on angiog raphy, in one of these patients autopsy revealed a haematoma within th e vessel wall, located between intima and media. One patient complaini ng of relapsing headaches had a posttraumatic basilar artery aneurysm. Conclusion: Dissections of the basilar artery can be separated in two types. In case of subintimal dissection patients present with vertebr obasilar ischaemia, which in contrast to extra-cranial dissections usu ally occurs without temporal delay. A second type of patients presents with subarachnoid haemorrhage. The dissection is subadventitial and p ierces through a thin adventitia into the subarachnoid space.