Hyperacute Vasospasm After Aneurysmal Subarachnoid Hemorrhage

Background Cerebral vasospasm after aneurysmal subarachnoid hemorrhage typically occurs 3–14 days after aneurysm rupture. We describe a series of patients who developed vasospasm within minutes of aneurysm rupture. This phenomenon, which we term, “hyperacute vasospasm,” has been reported in animal models of SAH, but hitherto has been poorly described in humans.