Cerebral amyloid angiopathy

Cerebral amyloid angiopathy, also known as congophilic angiopathy, is a form of angiopathy in which the amyloid protein associated with Alzheimer's disease, amyloid-β (Aβ), deposits in the walls of the blood vessels of the brain. The term congophilic is used because the presence of the abnormal aggregations of amyloid can be demonstrated by microscopic examination of brain tissue after application of a special stain called Congo red.

Amyloid deposition predisposes these blood vessel to failure, increasing the risk of a hemorrhagic stroke. Because it is the same amyloid protein that is associated with Alzheimer's dementia such brain hemorrhages are more common in people who suffer from Alzheimer's, however they can also occur in those who have no history of dementia. The hemorrhage within the brain is usually confined to a particular lobe and this is slightly different compared to brain hemorrhages which occur as a consequence of high blood pressure (hypertension) - a more common cause of a hemorrhagic stroke (or cerebral hemorrhage).