What is a Brain Aneurysm?
A brain aneurysm, also called a cerebral or intracranial aneurysm, is an abnormal outward bulging of one of the arteries in the brain. Aneurysms can occur in any artery of the body, but only those affecting the arteries supplying the brain can cause stroke. It is estimated that up to one in 15 people in the United States will develop a brain aneurysm during their lifetime.

Aneurysms can cause problems in several different ways. If the aneurysm ruptures, it causing bleeding into the brain or the space closely surrounding the brain, called the subarachnoid space, causing a subarachnoid hemorrhage. Subarachnoid hemorrhage from a ruptured brain aneurysm can lead to a hemorrhagic stroke, brain damage, and death. A patient with a subarachnoid hemorrhage usually suffers "the worst headache of his/her life" followed by nausea and vomiting. Double vision, neck stiffness, and loss of consciousness are also common. Less commonly, aneurysms cause problems not related to bleeding. An aneurysm can form a blood clot within it which can break away and be carried downstream until it obstructs a small arterial branch, causing a stroke. An aneurysm can also press against nerves (resulting in paralysis or abnormal sensation of one eye or of the face) or the adjacent brain (resulting in seizures). Your doctor may suggest an arteriogram (angiogram) if an aneurysm is suspected.

What is an arteriogram?
An arteriogram is a diagnostic study, usually performed by a radiologist, to assist in determining the cause of a stroke or subarachnoid hemorrhage and the treatment alternatives. A very thin, flexible catheter is introduced into an artery (usually at the groin) and then steered through the blood vessels of the body to the artery involved by the aneurysm. This is performed in an angiography suite, using x-rays to see the position of the catheter. A liquid containing water and iodine salts which can be seen on x-rays ("contrast") is injected through the catheter and the x-ray images are taken. This gives detailed pictures of the location, size, and shape of the aneurysm as well as a map of the arterial tree from which it arises. With this information, a decision will be made by you and your doctors as to how that particular aneurysm should be treated.

Incidence Rates of Brain Aneurysms

• Each year, approximately 0.2 to 3 percent of people with a brain aneurysm may suffer from bleeding.
• The annual incidence of aneurysmal subarachnoid hemorrhage in the U.S. exceeds 30,000 people. Ten to 15 percent of these patients will die before reaching the hospital and over 50 percent will die within the first thirty days after rupture. Of those who survive, about half suffer some permanent neurological deficit. This happens because the blood from the hemorrhage irritates the blood vessels on the surface of the brain, causing them to close (vasospasm). Vessels in vasospasm have difficulty supplying the brain with enough blood.
• Brain aneurysms can occur in people of all ages, but are most commonly detected in those ages 35 to 60.
• Women are actually more likely to get a brain aneurysm.

• Treatment
• Endovascular Coiling vs. Surgical Clipping

Next: Treatment

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