Subacute enlarging cerebral hematoma from amyloid angiopathy: case report.

We report the case of a 74-year-old woman who, during a 36-hour period, developed progressive, focal neurological deficits and eventual coma associated with a spontaneously enlarging intraparenchymal hematoma resulting from cerebral amyloid angiopathy. The subacute, progressive enlargement of the hematoma, confirmed by serial computed tomographic scans, supports the hypothesis that hematomas enlarge in amyloid angiopathy as a result of the replacement of the contractile elements of the arterial wall by noncontractile amyloid protein. This interference with vasoconstriction, the first phase of hemostasis, may be supplemented by local endothelial dysfunction causing alterations in the chemical mediators of hemostasis, thereby promoting hemorrhage and hematoma enlargement.