Cerebral Arterial Dissections
Key concepts
● hemorrhage into the tunica media of an artery
● may be spontaneous, posttraumatic, or iatrogenic (e.g. angiography-related), may be intracranial or extracranial
● may present with pain (usually ipsilateral H/A or carotidynia), Horner syndrome
● (in carotid dissections), TIA/stroke, or SAH
● extracranial dissections are usually treated medically (anticoagulation), intracranial dissections with SAH are treated surgically.
Nomenclature
Some confusion has arisen because of inconsistent terminology in the literature. Although by no means standard, Yamaura 1) has suggested the following:
▶ Dissection. Extravasation of blood between the tunica intima and media, creating luminal narrowing or occlusion.
▶ Dissecting aneurysm. Dissection of blood between the media and adventitia, or at the media, causing aneurysmal dilatation, which may rupture into the subarachnoid space.
▶ Pseudoaneurysm. Rupture of artery with subsequent encapsulation of the extravascular hematoma, may or may not produce luminal narrowing.