Proportions of Stroke Subtypes Among Men and Women ≥40 Years of Age in an Urban Japanese City in 1992, 1997, and 2002

Background and Purpose— Higher proportions of hemorrhagic stroke and lacunar infarction were reported in rural Japan compared with those in Western countries. We examined the relative proportions of stroke subtypes in an urban Japanese city where westernized lifestyles are more common than in rural areas. Methods— Stroke registration was performed in 1992, 1997, and 2002 for residents ≥40 years of age who were admitted with acute strokes to all of the 10 hospitals with ≥90 beds in Yao City, Osaka, Japan. Strokes were classified as intraparenchymal hemorrhage, subarachnoid hemorrhage, or ischemic strokes (embolic infarction, large-artery occlusive infarction, lacunar infarction, and unclassified thrombotic infarction) by criteria using computed tomography or MRI. Results— A total of 650 first-ever strokes were registered. The age-adjusted proportion of each stroke subtype was not significantly different among the 3 study periods in both men and women. Throughout the 3 periods, intraparenchymal hemorrhage, ...