Subtypes and proportions of cerebrovascular disease in an autopsy series in a Japanese geriatric hospital.

Of 1721 consecutive autopsies performed on patients over 60 years of age in Tokyo Metropolitan Geriatric Hospital, 550 (32% of all autopsied cases) revealed symptomatic cerebrovascular lesions. Among the 550 patients, intracranial hemorrhage was found in 19%, cerebral infarction in 75%, and coexisting cerebral hemorrhage and cerebral infarction in 6%. Twenty-eight percent of the cerebral infarctions were embolic infarctions of cardiac origin, half of which were caused by nonvalvular atrial fibrillation, and 69% were non-embolic infarctions of cardiac origin. Progressive subcortical vascular encephalopathy accounted for 15% of the cerebral infarctions. Two-thirds of all lobar cerebral hemorrhages were amyloid angiopathy-related. Nonvalvular atrial fibrillation is the most important cardiac source of embolic stroke. Progressive subcortical vascular encephalopathy is one of the characteristic features of ischemic lesions, and cerebral amyloid angiopathy is an important cause of lobar cerebral hemorrhage in the aged.