Cerebral amyloid angiopathy (CAA) refers to the deposition of β-amyloid in the media and adventitia of small and mid-sized arteries (and, less frequently, veins) of the cerebral cortex and the leptomeninges.
It is a component of any disorder in which amyloid is deposited in the brain, and it is not associated with systemic amyloidosis.
CAA has been recognized as one of the morphologic hallmarks of Alzheimer disease (AD), but it is also often found in the brains of elderly patients who are neurologically healthy.
While often asymptomatic, CAA may lead to dementia, intracranial hemorrhage (ICH), or transient neurologic events. ICH is the most recognized result of CAA.