Cerebrovascular Neurosurgery - Subarachnoid Hemorrhage

When a brain aneurysm ruptures, it causes bleeding into the compartment surrounding the brain—the subarachnoid space—causing a subarachnoid hemorrhage. Often the aneurysm heals over, bleeding stops, and the person survives. In more serious cases, the bleeding may cause brain damage with paralysis or coma. In the most severe cases, the bleeding leads to death.


Fifty per cent of people with subarachnoid hemorrhage die within minutes. Of the fifty per cent who survive, half will suffer delayed death. The remainder usually live with severe long-term deficits, depending upon the level of hemorrhage suffered.

What happens to the brain when an aneurysm bleeds?

Once a hemorrhage has occurred, one of several things can happen. In most cases, the bleeding after a rupture quickly stops. However, any brain cells touched by the leaked blood may become damaged. Blood leaked into the cerebrospinal fluid increases the pressure on the brain.

What are the treatment options for ruptured aneurysms?

Aneurysms that have ruptured require swift treatment to prevent the risk of a subsequent rupture. Rebleeding, which is very common following the rupture of an aneurysm (especially within the first two weeks), is usually more severe than the initial rupture.

Aneurysms may be treated by surgical clipping or endovascular coiling. The optimal treatment depends upon the patient's history, physical condition, age, and risk factors, as well as the anatomical characteristics of the aneurysm.