Brain Aneurysm Might Have Genetic Component

Q:  I recently read that aortic aneurysms are hereditary. My father had a ruptured brain aneurysm when he was my age (63). He was operated on and recovered, but was never the same afterward. He died about 7 years later from a stroke.

Are brain aneurysms hereditary, and if so are there any preventive measures I can take or diagnostic procedures I should have done?

A:  I can certainly understand your concern about your chances for having a stroke like your father, especially now that you've reached the same age when he had problems.

An aneurysm is a weakness or abnormality of the blood vessel, which could make it more prone to burst and result in bleeding in the brain. Most people with aneurysms don't have any warning symptoms. With large aneurysms, the risk of rupture is about 1% per year. The good news is that small aneurysms usually don't bleed. Risk of death with brain hemorrhage is as high as 50% to 70%, and even patients who survive might have suffered a stroke with lasting effects.

Patrick Walsh, MD, PhD, Professor of Neurosurgery at the Medical College of Wisconsin, told me that he is frequently asked if aneurysms are hereditary, but the answer is not really known. Because the incidence of aneurysm is fairly high in the general population (about 3% as found on autopsy), you could expect to see a couple of people in a large extended family with them, just by the odds. In some families there may be a genetic link. Dr. Walsh has taken care of one woman whose 5 siblings all had aneurysms in the brain.

There are some factors that point to a higher risk.

1. Multiple aneurysms - Did your dad have just one aneurysm or several?

2. Aneurysms in several generations - Do you have any great uncles, aunts, cousins etc. in whom aneurysms have been found?

3. Personal risk factors - Do you smoke, have other vascular or heart disease, have high cholesterol, or have high blood pressure that would make you more at risk for rupture?

Since a ruptured aneurysm can be devastating or even fatal, I believe that for your peace of mind it makes sense to have your brain evaluated. Discuss with your doctor the options of an MRI or an MR angiogram that specifically focuses on the blood vessels. Both procedures may be required. Fortunately they are low-risk, but unfortunately they are costly.

"Dear Doctor" is a compilation of patient questions answered by doctors from the Medical College of Wisconsin.