Delayed Arterial Spasm Following Subarachnoid Hemorrhage

Delayed arterial spasm was observed in recently studied (1967–1970) patients with subarachnoid hemorrhage from a middle cerebral artery aneurysm. The smallest arterial measurements were obtained 5–13 days after the most recent hemorrhage. This pattern was not found in patients studied previously (1959–1967). The factor or factors responsible for such delayed spasm are not known. Age did not affect susceptibility to spasm.