Angiography study of cerebral vasospasm following the rupture of intracranial aneurysms: Part II. Relation between the site of aneurysm and the occurrence of the vasospasm.

The relation between the occurrence of vasospasm and the site of ruptured aneurysm was investigated. Vasospasm tended to occur initially on arteries close to the aneurysm, later extending to other locations. Contralateral spasm was more frequent the closer the site of the aneurysm to the mid-sagittal line. The spasm observed angiographically varies in relation to the site of the aneurysm; the site of the hematoma in the subarachnoid space was supposed to be the cause of such variation.