A brain aneurysm is a swelling of one of the blood vessels in the brain. While the swelling itself is not necessarily dangerous, the aneurysm can burst, resulting in a hemorrhagic stroke. The aneurysm can also contribute to the development of blood clots, which can travel into the brain and cause damage. For these reasons, brain aneurysms are viewed as cause for serious concern by medical professionals, and steps may be taken to treat an aneurysm in the brain before it has a chance to burst or contribute to clotting in the brain.
Aneurysms in general are simply swellings of blood vessels. They can be caused by a variety of things, from a congenital weakness in the wall of the blood vessel which causes it to bulge, to a medical condition which weakens the vessel walls or puts pressure on them, causing them to swell. Often, an aneurysm goes undetected until it bursts, because the swelling does not usually cause symptoms. Aneurysms are common both the aorta and the brain, in addition to being found in other areas of the body.
The most common site for a brain aneurysm is a bundle of big arteries at the base of the brain in an area known as the Circle of Willis. While the swelling is small, the patient does not experience symptoms. As it grows, some neurological issues like headaches and vomiting could occur, and if the aneurysm bursts, the patient will develop the signs of stroke, indicating that bleeding is occurring in the brain.
This type of aneurysm is also sometimes known as a cerebral or intracranial aneurysm. A brain aneurysm can be diagnosed with medical imaging studies in which the vascular system in the brain is examined. Such a study may be ordered if a patient is at risk, as in the case of families with hereditary aneurysms, or when a patient demonstrates symptoms which could indicate a problem in the brain.
Once identified, a brain aneurysm can be left in place or treated, depending on the location, the size, and the degree of risk. One treatment, endovascular embolization, also known as coiling, involves the insertion of a coiled wire into the aneurysm, forcing it to clot and thereby eliminating it. Clipping surgery, in which the base of the aneurysm is sealed shut with a clip, is also an option. Clipping is much more invasive, but also more reliable for eliminating a brain aneurysm.