Understanding the brain aneurysm

A brain aneurysm is a relatively small blood-filled protrusion - a bubble - under pressure in an artery at the base of the brain and is prone to rupture. Dr. David Chalif, chief of neurovascular neurosurgery at North Shore University Hospital in Manhasset, discussed the condition, treatments and theories about its cause.

Are aneurysms rare?

An estimated 5 percent of all adults harbor an aneurysm that persists silently and causes no symptoms.

Are there symptoms of a possible rupture?

When an aneurysm bursts, it does so without warning - out of the blue. Nevertheless, there may be a "sentinel leak." Patients who have experienced leakage will complain of a severe headache, a thunderbolt of pain. A majority describe it as the worst headache of their lives.

How common are ruptured aneurysms?

In the United States there are about 50,000 ruptured aneurysms annually. For Nassau, Suffolk and Queens, a rough estimate would put the number of ruptures at about 100 to 200 a year. Statistics from the Brain Aneurysm Foundation indicate 15 percent to 25 percent of patients with a ruptured aneurysm die before reaching a hospital. Up to half of all patients who've experienced a rupture die within 30 days of the rupture.

Can aneurysms be successfully treated?

Yes. New minimally invasive techniques can block the aneurysm's blood supply, resulting in shrinkage of the bubble.

Why do aneurysms occur?

Aneurysms occur in areas of arterial weakness, often in the muscle layer of the artery. The weak area bulges out and forms a blood-filled bubble, which is under pressure and at risk of rupturing.

Are aneurysms likely to occur anywhere in the brain?

Aneurysms, for the most part, occur in any one of the vessels in the Circle of Willis, a ring of arteries with multiple branch points at the base of the brain.

At what age are aneurysms most likely to occur?

An aneurysm can occur at any age, but the average age of rupture is about 55. Some patients are as young as 9; others are in their 80s. Mostly, it's a condition of middle age.

What are some risk factors?

Anyone can develop an aneurysm, but smoking and high blood pressure can increase the likelihood that an aneurysm will enlarge or rupture. For reasons that have not yet been fully explained, people with polycystic kidney disease are at increased risk. Familial cases also confound medical science. Aneurysms tend to run in some families from one generation to the next, placing members at elevated risk.

Is screening available?

Screening is available for people at high risk, which includes patients with polycystic kidney disease and those from families at high risk. Screening is not available for the general population.

Additional source material: Brain Aneurysm Foundation