Cerebral Amyloid Angiopathy

Cerebral amyloid angiopathy is a major cause of hemorrhagic stroke, a frequent contributor to age-related cognitive impairment, and a key component in adverse responses to beta-amyloid (Aβ) immunotherapy. Defined by pathological deposition of Aβ in the small blood vessels of the brain, cerebral amyloid angiopathy is most often diagnosed on the basis of magnetic resonance imaging studies showing multiple hemorrhages or leptomeningeal blood products within or overlying the cerebral cortex. The disorder typically manifests as hemorrhagic stroke or as a contributing factor to cognitive decline and, less commonly, with transient focal neurologic symptoms or a cerebral inflammatory autoimmune syndrome. The high risk of recurrent hemorrhagic strokes associated with cerebral amyloid angiopathy poses a particular challenge in patients with indications for antithrombotic therapy and dictates a carefully individualized weighing of risks and benefits. Ongoing research is focused on tools to aid in risk prediction, early diagnostic markers, and identification of key pathogenic steps as targets for disease-modifying therapies.