Cerebral amyloid angiopathy-related hemorrhage in a middle-aged patient with Down's syndrome.

A patient with Down's syndrome (DS) died of cerebral hemorrhage at age 52. At autopsy, a large sub-cortical hematoma was present in the right frontal lobe, and microscopic examination showed numerous senile plaques and neurofibrillary tangles in an extensive area of neocortex and also disclosed heavy involvement of vascular walls by amyloid deposition. These senile plaque and vascular amyloid deposits were specifically stained with an antibody to Abeta. His APOE genotype was epsilon4/epsilon4. This is a rare case of DS with cerebral amyloid angiopathy (CAA)-related cerebral hemorrhage. Genetic factors, such as APOE genotype, conceivably determine the risk of vascular rupture in individuals with CAA, even among patients with DS.