[Stroke in young adults in Japan].

The details of stroke in young adults remain unknown in Japan. We performed a multicenter survey to establish a stroke data bank for young adults in Japan. We collected clinical data of 7,245 acute stroke patients admitted to 18 hospitals in Japan. In patients admitted within the first 7 days of stroke, patients aged = < 50, = < 45, and = < 40 accounted for 8.9%, 4.2%, and 2.2%, respectively. Hypertension, diabetes mellitus, hypercholesterolemia, and non-valvular atrial fibrillation were significantly more frequent in the non-young than in the young, but smoking habits and patent foramen ovale were more frequent in the young than in the non-young. Brain infarction was the most predominant stroke subtype in the non-young, but not so in the young (62.6% vs. 36.7%, p < 0.01). Brain hemorrhage (20.8% vs. 32.1%, p < 0.01) and subarachnoid hemorrhage (7.3% vs. 26.1%, p < 0.01) were more frequent in the young. Causes of brain infarction and hemorrhage were often atypical in the young (2.8% vs. 25.1%, p < 0.001 and 4.6% vs. 20.2%, p < 0.0001, respectively). Causes of stroke in the young was often atypical, such as cerebral arterial dissection, Moyamoya disease, antiphospholipid syndrome, arteriovenous malformation, et al. Because causes and underlying risk factors of stroke in young adults were quite different from those in older patients, we need to establish the data bank and to explore optimal measures of the diagnosis and management for young stroke patients.