若年者脳卒中診療の現状に関する共同調査研究　　若年者脳卒中共同調査グループ（ＳＡＳＳＹ‐ＪＡＰＡＮ）

Purpose and background<BR>Stroke in young adults differs from that in older persons. However, the detailed characteristics of stroke in young adults remain unknown in Japan. We therefore performed a multicenter survey to establish a stroke data bank for young adults in Japan.<BR>Methods<BR>We collected clinical data for 7, 245 acute stroke patients admitted to 18 hospitals in Japan. Among them, 5, 661 were 51 years old or more (the non-young group) from 1998 to 1999 and 1, 584 were 50 years old or less (the young group) from 1995 to 1999.<BR>Results<BR>Among the patients admitted within the first 7 days of stroke from 1998 to 1999, those aged=<50, = <45, and=<40 accounted for 8.9%, 4.2%, and 2.2%, respectively.<BR>Hypertension (62.7% vs. 48.5%, p<0.01), diabetes mellitus (21.7% vs. 13.6%, p<0.01), hypercholesterolemia (16.5% vs. 13.1%, p<0.01), and non-valvular atrial fibrillation (21.2% vs. 4.7%, p<0.01) were significantly more frequent in the non-young group than in the young group. On the other hand, a smoking habit (19.3% vs. 27.3%, p<0.01) and patent foramen ovale (0.7% vs. 1.2%, p=0.07) were more frequent in the young group than in the non-young group.<BR>Brain infarction was the most predominant stroke subtype in the non-young group, but not in the young group (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 group. Transient ischemic stroke was comparable in frequency between the two groups (5.7% vs. 5.0%).<BR>The causes of brain infarction and hemorrhage were often atypical in the young group (2.8% vs. 25.1%, p<0.001, and 4.6% vs. 20.2%, p<0.0001, respectively). Among patients with brain infarction, they were often atypical:cerebral arterial dissection in 41 patients, Moyamoya disease in 33, antiphospholipid syndrome in 14, fibromuscular dysplasia in 3, sinus thrombosis in 3, polyhemia in 3, and dolicoectasia in 3. The sites of brain infarction were more predominantly in the vertebrobasilar than in the carotid territory (24.9% vs. 32.2%, p<0.001). Among patients with parenchymal hemorrhage without hypertension, arteriovenous malformation was demonstrated in 83 and Moyamoya disease in 13. Among patients with subarachnoid hemorrhage without saccular aneurysm, arterial dissection was noted in 16 and arterial venous malformation in 11.<BR>Conclusion<BR>Since the causes and underlying risk factors of stroke in young adults tend to be quite different from those in older patients, we need to establish a detailed data bank and to explore the optimal measures for the diagnosis and management of young stroke patients.