The medical word aneurysm means ballooning out of an artery, causing the affected wall of the artery to stretch (from the high pressure inside it) to form a "bubble," whose wall is thinner (and weaker) than normal. So, brain aneurysm, also called intra-cerebral or intracranial aneurysm, is a medical condition where the cerebral artery in the brain has formed such "bubble." This can happen to any artery in the brain but usually the arteries that cross between the base of the skull and the undersurface of the brain are the ones involved.

Majority of brain aneurysms are congenital, an inborn genetic predisposition which makes them prone to such arterial wall weakness and "bubble" formation in the brain artery, which is riskier among those with high blood pressure. The out pouching or ballooning usually forms at the site where the artery branches off. Brain aneurysms are more prevalent among those with genetic illnesses, like connective tissue disorders, polycystic kidneys, and arterio-venous malformations. Other causes include infection in the wall of the artery, trauma, tumors, hardening of the arteries, cigarette smoking, drug abuse and the use of oral contraceptives.

Cerebral aneurysm is not uncommon. Up to about 4 percent of autopsies revealed the present of cerebral aneurysm, and about 5 percent of people will have brain aneurysm during their life. Ten percent of them will have a rupture (aneurysm bursting). A rough estimate reports that annually between 25,000 to 50,000 people in the United States will have a brain hemorrhage due to ruptured brain aneurysm. The incidence is higher among women and among African-American.

Quite often a brain aneurysm goes undetected, without causing any problem, without any symptoms. The first sign shows when the aneurysm ruptures, usually a sudden severe headache, the worst the individual has ever experienced. Some other symptoms might include nausea, dizziness, sensitivity to light, neck pains, fainting, seizures, and in some cases, patients lapse into coma. Thirty to 50 percent of patients suffer minor bleeds (called "warning leaks") which later eventually lead to a massive brain hemorrhage a few days after the episodes.

Statistically, the highest incidence of rupture is found among persons in their middle age (in their 40s and 50s), but it could happen at any age, even among teenagers with cerebral aneurysm.

A congenital vascular defect known as arterio-venous (AV) malformation is a condition that could mimic brain aneurysm. It can also lead to vascular rupture and cause brain hemorrhage. However, the pathology here is an abnormal connection between an artery and a vein in the brain. Normally, there is no connection between an artery and a vein, except at their terminal endings. The clinical presentation in AV malformation is very similar to brain aneurysm.

The way to reduce the danger of an aneurysm growing and bursting among those who have been diagnosed to have it or those who are suspected to have it includes living a healthy lifestyle, no smoking, moderation in alcohol intake, avoidance of heavy exertions, and effective treatment of high blood pressure, if present. Persons with recurrent headaches should seek medical check-up, and those with high blood pressure should be treated promptly and continuously.

When brain aneurysm is suspected, the best thing to do is to seek immediate medical treatment. If the diagnosis is confirmed and surgery is deemed feasible, it is the best option to take. Two procedures used to stop the bleeding include Microvascular Clipping (where the leaking artery is clipped during surgery) and an alternative to surgery, a less invasive procedure called Endovascular Embolization, where a coil is inserted into the leaking artery to cause clotting within the artery, thereby stopping the hemorrhage.

Unfortunately, the outcome is not very certain. When the cerebral artery bursts and causes brain hemorrhage, sudden death can result. The mortality rate following a rupture is about 40 percent, and another 25 percent die from complications. Prognostication in this condition is medically difficult since many variable factors come into play. When a window of opportunity presents itself to allow institution of medical treatment, the prognosis becomes better. Once definitive treatment, either with clipping or embolization is initiated, the outlook significantly improves. A healthy lifestyle, together with vigilance about health, is fundamental, not only in dealing with aneurysms but with any other diseases, cardiovascular, metabolic, infectious, etc. Health, after all is indeed wealth. #