A brain aneurysm is the ballooning of a weak area on the wall of an artery in the brain. An aneurysm can leak or rupture causing blood to escape into the brain. This is an emergency condition, as the blood can damage brain tissue and increase pressure inside the skull, disrupting oxygen supply to the brain, which can lead to unconsciousness or even death. Brain aneurysms usually develop in the arteries at the base of the brain, at weak points where the arteries branch off or fork. They are more common in women than men. Substance abuse, head injury, arteriosclerosis (hardening of the blood vessels), high blood pressure, aging, certain congenital diseases and a positive family history increase your risk of developing a brain aneurysm.
Brain aneurysms that have not ruptured usually produce no symptoms, but may sometimes produce pain near the eye, visual disturbances, a drooping eyelid, or weakness, numbness or paralysis on one side of the face. The main symptom of a ruptured aneurysm is a sudden unusually severe headache. Other symptoms may include nausea and vomiting, neck stiffness, confusion, blurred vision, fainting and seizures.
If you have symptoms that suggest a ruptured brain aneurysm, your doctor will perform imaging studies such as CT or MRI scans to view the area of bleeding. If these are inconclusive, a cerebral angiography (studies the blood vessels in the brain with the help of a dye) may be ordered. A sample of your cerebrospinal fluid (fluid that surrounds the brain and spinal cord) may also be removed and tested for blood cells, indicating bleeding.
Small aneurysms with minimal symptoms are usually monitored closely. Treatment depends on the size and location of the aneurysm. Symptoms are relieved with medication to manage pain and prevent complications such as seizures, stroke or narrowing of blood vessels. If you have difficulty with speech and movement due to brain damage, appropriate rehabilitation is provided.
Surgery is indicated to treat ruptured or large aneurysms and involves two techniques. Microvascular clipping is a technique that involves identifying the area of the artery that forms the neck of the aneurysm and clipping it with a metal clip. If the artery is significantly damaged by the aneurysm, the entire artery may be clamped and the area of the aneurysm bypassed with a vessel graft. This involves cutting through the skull to access the aneurysm. Alternatively, your doctor may perform a minimally invasive procedure called endovascular embolization, where metallic coils inserted through a catheter are released into the aneurysm.