Cerebral CT and MRI findings in cervicocephalic artery dissection.

Purpose: To explore the frequency and patterns of brain infarction and other brain manifestations in cervicocephalic artery dissection (CCAD) and to evaluate the correlation between vessel wall findings and infarctions.

Material And Methods: The medical records and films of 136 consecutive CCAD patients diagnosed in Oulu University Hospital during the 20-year period since 1982 were reviewed. Five patients with no brain imaging were excluded.

Results: One-hundred-and-twenty-seven patients underwent cerebral CT and four patients MRI. Brain infarction was detected in 73 patients (56%), 43 of whom had cerebral infarction associated with anterior circulation dissection and 30 cerebellar infarction associated with posterior circulation dissection. Occlusion of the dissected vessel was accompanied by infarction in 76%, irregular stenosis in 40%, and other findings in 12%. Of the anterior circulation infarctions, territorial and subcortical infarctions and territorial infarctions with fragmentation, which are considered embolic, accounted for 95%, while only 5% were in the watershed area and considered hemodynamic. Intracranial posterior circulation dissection rarely caused infarction (in 1/11 of the dissected vessels), whereas intracranial anterior circulation dissection resulted in infarction more commonly (9/12). Altogether 23% of patients with intracranial CCAD had subarachnoid hemorrhage. Hemorrhagic transformation was present in five patients.

Conclusions: More than half of CCAD patients have cerebral or cerebellar infarction at CT or conventional MR imaging. Occlusion of the dissected vessel is accompanied by infarction more often than other vessel wall abnormalities. Most cerebral infarctions caused by arterial dissections are of embolic origin. Intracranial dissections cause subarachnoid hemorrhage in more than 20% of patients.