Spontaneous intracranial carotid artery dissection.

A previously healthy 46-year-old woman had the abrupt onset of aphasia and right hemiplegia from a large left-hemisphere infarct. At postmortem examination the cause of the infarct was dissection and occlusion of the intracranial carotid artery. No preexisting abnormality was found to account for the dissection. This uncommon cause of stroke and its pathogenesis are discussed.