Brain Hemorrhage (Intracranial Bleeds)
What is it?
A brain hemorrhage, one of the two main types of strokes (see Stroke for more information), results when a ruptured artery causes bleeding into the brain (intracerebral bleed) or into the space between the membranes surrounding the brain (subarachnoid hemorrhage). Damage occurs two ways. First, blood supply is cut off to the parts of the brain beyond the site of the rupture in the artery. Second—and more dangerous—the escaped blood forms a mass that increases pressure on the surrounding brain tissue. Blood continues to flow until it coagulates or until it simply has no place left to go. Intracerebral bleeds usually occur in the cerebrum, the part of the brain that controls higher functions such as speaking and reasoning. Subarachnoid hemorrhages usually occur at the base of the brain and are usually due to rupture of cerebral aneurysms. Massive hemorrhages are usually fatal; indeed, only about 25 percent of patients survive.
What Causes It?
- High blood pressure is the main cause.
- Atherosclerosis (the buildup of fatty plaque in the arteries) weakens arterial walls, further increasing the risk of bleeds due to hypertension.
- Bleeding disorders (such as hemophilia and leukemia) or the use of anticoagulant or thrombolytic drugs increase the risk of intracerebral bleeding.
- Aneurysms (weak spots in the wall of an artery that may burst) are a major cause of subarachnoid hemorrhage. They are often due to congenital defects.
- Blood vessel abnormalities such as arteriovenous malformation (AVM) may result in a stroke.
- A head injury may rupture arteries in the brain.
- Brain tumors may lead to intracerebral bleeding.
- An increasingly recognized cause of brain hemorrhage in the elderly is amyloid angiopathy. Amyloid—a protein found in the brain of people with Alzheimer's disease—is deposited in the brain vessels, causing them to weaken. Indeed, patients with Alzheimer's disease are at greater risk for amyloid-related brain hemorrhages.
Prevention
- Keep blood pressure and weight under control.
- People with undiagnosed aneurysms often will have severe, sudden, unusual headaches initially. If the cause of these can be identified, arteriography (diagnostic imaging of the arteries) may reveal a surgically treatable aneurysm.
Diagnosis
- A lumbar puncture (spinal tap) may be used to test for blood in the cerebrospinal fluid.
- CT (computed tomography) scans of the head may be taken to identify and assess the amount of blood spillage in the brain.
- MRI (magnetic resonance imaging) can detect abnormal blood vessels, underlying tumors, and some aneurysms.
- Arteriography may be used to detect cerebral aneurysms and arteriovenous malformations.
How to Treat It
- Call an ambulance if you develop symptoms of a brain hemorrhage.
- After careful evaluation, physicians may take emergency measures to reduce blood pressure in order to minimize flow of blood from the ruptured artery.
- Life support may be necessary.
- Surgical repair, if attempted at all, is usually delayed for one to two weeks after the incident, although another approach calls for more rapid surgical intervention in some cases.
When to Call a Doctor
- EMERGENCY Call an ambulance immediately
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Copyright © 2008 Medletter Associates, LLC
Content excerpted from Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference.