Cerebrovascular accidents resulting from segmental mediolytic arteriopathy of the cerebral arteries in young adults.

Five cases of cerebrovascular accident or transient ischaemia in young adults resulting from segmental mediolytic arteriopathy are reported. The aetiology of segmental mediolytic arteriopathy is unknown but the disorder is characterized by focal, non-inflammatory mucoid degeneration of the media of muscular, non-arteriosclerotic arteries, frequently involving cerebral intracranial or extracranial vessels. It is similar to Erdheim-Gsell's medionecrosis of the aorta and may occur in any muscular artery. The consequences are mostly fatal in cerebral arteries. Histological analysis of each case is described. Clinicians should be aware of the possibility of intramural haemorrhage and dissecting aneurysm as a result of mucoid degeneration of the arterial media in young adults with cerebrovascular accident.