Cerebral Atherosclerosis in Japanese. I. Age Related to Atherosclerosis

During a period of approximately two years (1965 through 1966), 717 intracranial cerebral arteries (males and females) were obtained from the medicolegal autopsy cases. Systematic grading of the macroscopic severity of cerebral atherosclerosis was performed and the results were reported. In general, cerebral atherosclerosis appeared as early as the second decade and increased in severity with age, particularly at the fifth decade in males and the sixth decade in females. The prevalence of localization of early and/or severe cerebral atherosclerosis was studied. The results in the present study were not the same as in the previous investigations on Caucasians. The common sites of the severe cerebral atherosclerosis causing marked lumen narrowing were the proximal portion of posterior cerebral arteries, peripheral portion of the middle cerebral arteries, and the vertebral arteries and their fusing site at the basilar artery; the internal carotid artery was the least commonly involved. In the present study, the influence of sex in the production of cerebral atherosclerosis was suggested, and the simple senescence theory of cerebral atherosclerosis was not supported. The macroscopic severity of cerebral atherosclerosis of Japanese in the present study appeared to be equal to or slightly greater than that in Americans and Norwegians reported by Baker et al.