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[Cerebral arterial dissection].

We investigated a total of 98 cases with stroke caused by cerebral arterial dissection recruited in Strategies against Stroke Study for Young Adults in Japan (SASSY-Japan). The most frequent site of dissection was the intracranial vertebrobasilar artery. The stroke subtype was divided into ischemic (TIA and cerebral infarction) and hemorrhagic types (subarachnoid hemorrhage). The ischemic type was predominant (69%) and patients with the ischemic type were younger than those with the hemorrhagic type (P < 0.01). In the intracranial arterial dissection, nearly all cases were of the ischemic type. In contrast, in the extracranial arterial dissection, 60% of cases were ischemic and 40% were hemorrhagic. Cerebral angiography was the most important diagnostic procedure in the hemorrhagic type. In the ischemic type, MRI and MRA were more frequently used to show the findings specific to the dissection such as an intimal flap or double lumen and intramural hematoma. The outcome at discharge is generally good such that the modified Rankin Score was among 0-II in 69% of cases. However, in the hemorrhagic type, recurrence during an acute stage was frequent, and the outcome was poor with a mortalit rate of 19%. The establishment of an effective intervention to prevent the recurrence of subarachnoid hemorrhage is urgently required.