Brain (Cerebral) Aneurysms

Cerebral (Brain) Aneurysm

Cerebral aneurysms are abnormal bubbles or blisters on the blood vessels (usually arteries) in and around the brain. Cerebral (brain) aneurysms are estimated to be present in about 5% of the general population, and 20% of aneurysm patients may actually have more than one aneurysm. Also known as “berry aneurysms,” most brain aneurysms are sporadic, in other words they occur without any particular cause or reason. Although the exact cause of brain aneurysms is not known, both smoking and high blood pressure (hypertension) have been linked to the development of aneurysms. Aneurysms are associated with other brain blood vessel problems, including arteriovenous malformations (AVM) and Moyamoya disease. Some patients with rare diseases such as polycystic kidney disease, fibromuscular dysplasia, connective tissue disorders, and coarctation of the aorta aneurysms may also be prone to developing aneurysms. Many physicians recommend that patients with these disorders or with a family history of cerebral aneurysms (two or more first degree relatives in the same family) undergo noninvasive screening. Screening can be done using Magnetic Resonance Angiography (MRA).

Cerebral aneurysms are generally estimated to rupture at a rate of 1 to 2% per year. This rate is cumulative. However, certain types of aneurysms may have considerably lower or higher rupture rates. While the overall aneurysm rupture rate is rather low, the death rate after a hemorrhage is high. The thirty-day mortality rate (the percentage of people that die within thirty days) after aneurysmal SAH is approximately 50%. Of those that survive, about half suffer significant disability. Besides bleeding, aneurysms can also cause problems by putting pressure on other important nearby structures as they grow.