Subarachnoid hemorrhage

Is bleeding in the area between the brain and the thin tissues that cover the brain.

Bleeding into the space between the brain and the arachnoid membrane (the middle membrane covering the brain). This is a life-threatening condition that can lead to stroke, seizure, brain damage, or death. It may result in permanent brain damage caused by ischemia (loss of blood flow) or bleeding into the brain tissue. Most often, a subarachnoid hemorrhage is caused by a cerebral aneurysm that has ruptured or burst. However, it may also be a result of other blood vessel abnormalities (such as an arteriovenous malformation) or trauma.

Bleeding into the subarachnoid space surrounding the brain, which causes severe headache with stiffness of the neck. The usual source of such a hemorrhage is a cerebral aneurysm that has burst. The diagnosis is confirmed by finding blood-stained cerebrospinal fluid at lumbar puncture. Identification of the site of the aneurysm, upon which decisions about treatment will be based, is achieved by cerebral angiography.

Bleeding into the subarachnoid space of the brain, usually because of the rupture of an intracranial aneurysm or arteriovenous malformation, and occasionally because of hypertensive vascular disease. The bleeding causes intense headache pain, often with nausea and vomiting, loss of consciousness, paralysis, and, in some cases, coma, decerebrate posturing, and brain death. About 30,000 Americans are affected annually. Prompt diagnosis is facilitated by neuroimaging or lumbar puncture. A neurosurgical consultation should be obtained.