Very late-onset symptomatic cerebral vasospasm caused by a large residual aneurysmal subarachnoid hematoma--case report.

A 70-year-old female developed delayed ischemic neurological deficits at 35 days after subarachnoid hemorrhage (Hunt and Kosnik grade III, Fisher group 4) caused by a ruptured aneurysm of the left middle cerebral artery. Angiography indicated late-onset cerebral vasospasm probably due to the mass effect of a large hematoma remaining in the sylvian fissure and an intracerebral hematoma after surgery. Patients with a large subarachnoid hematoma after subarachnoid hemorrhage should receive therapy to prevent cerebral vasospasm until the mass effect of the hematoma has diminished.