Mexican Americans and women may be at higher risk for subarachnoid hemorrhage, a type of stroke involving bleeding in the space around the brain, according to a study published in the June 11, 2008, online issue of Neurology®, the medical journal of the American Academy of Neurology.

People with this type of bleeding in the brain may have a severe or “thunderclap” headache that is sometimes described as the worst headache of a person’s life. Other symptoms that may accompany the headache include vomiting, seizures and neck stiffness. The condition is usually caused by a cerebral aneurysm, a blistering of a blood vessel, and can lead to death or severe disability even when caught early.

For the study, researchers reviewed the medical records of 29,907 people in southeast Texas and identified 107 people age 44 and older who had experienced a subarachnoid hemorrhage over seven years. Of those, 43 were white and 64 were Mexican American. Sixty-seven percent were women.

The results showed that Mexican Americans were one and two-thirds times more likely to have a subarachnoid hemorrhage than white people. Women in the study had a one and three-quarters-fold increased risk of having this type of stroke.

“Physicians and public health officials should help Mexican Americans and women take steps which might prevent subarachnoid hemorrhage,” said study author Lewis B. Morgenstern, MD, Professor and Director of the University of Michigan Stroke Program in Ann Arbor and Fellow of the American Academy of Neurology. “Given that Mexican Americans account for the largest and fastest-growing minority group in the United States, it is important to examine how this condition may affect certain ethnicities differently.”

Morgenstern says differences in tobacco use and the treatment of hypertension between ethnic groups may have played a role in the study’s outcome. He also cautions that the study took place in one geographic area, so results may notbe the same in other locations.

About Strokes 

A stroke is an interruption of the blood supply to any part of the brain.A stroke is sometimes called a "brain attack."  Every 45 seconds, someone in the United States has a stroke. A stroke can happen when:

• A blood vessel carrying blood to the brain is blocked by a blood clot. This is called an ischemic stroke.  Usually this type of stroke results from clogged arteries, a condition called atherosclerosis.  Fatty deposits collect on the wall of the arteries, forming a sticky substance called plaque. Over time, the plaque builds up. Often, the plaque causes the blood to flow abnormally, which can cause the blood to clot.
• A blood vessel breaks open, causing blood to leak into the brain. This is a hemorrhagic stroke. If blood flow is stopped for longer than a few seconds, the brain cannot get blood and oxygen. This can occur when small blood vessels in the brain become weak and burst. Some people have defects in the blood vessels of the brain that make this more likely. The flow of blood after the blood vessel ruptures damages brain cells.

High blood pressure is the number one reason that you might have a stroke. The risk of stroke is also increased by age, family history of stroke, smoking, diabetes, high cholesterol, and heart disease.

Certain medications increase the chances of clot formation, and therefore your chances for a stroke. Birth control pills can cause blood clots, especially in woman who smoke and who are older than 35.

Men have more strokes than women. But, women have a risk of stroke during pregnancy and the weeks immediately after pregnancy.

Cocaine use, alcohol abuse, head injury, and bleeding disorders increase the risk of bleeding into the brain.