Cerebral amyloid angiopathy (ACys/CAA) is a rare cerebrovascular disease characterized by the accumulation of amyloid beta peptide in the leptomeninges and small/medium cerebral blood vessels. The amyloid deposits lead to fragile vessels that may manifest in lobar intracerebral hemorrhage. This systemic amyloidosis may also present with cognitive impairment, incidental microbleeds, hemosiderosis, inflammatory leukoencephalopathy, Alzheimer's disease, or transient neurologic symptoms.
ACys amyloidosis can be hereditary but also sporadic.