Women, Mexican-Americans at higher risk of ruptured brai...(urgery at the U-M Medical School and of ...),Health

The study is the latest to arise from the BASIC project, whose name comes from Brain Attack Surveillance in Corpus Christi. The project involves surveillance for all strokes and mini-strokes in Nueces County, and detailed analysis of anonymous patient records.

Previously, using data from BASIC, Morgenstern and his colleagues have shown differences between ethnic groups and genders in other types of stroke including the most common type, ischemic.

The new paper is based on data from 107 subarachoid hemorrhage patients over the age of 44 who experienced their stroke between 2000 and 2006. All of their diagnoses were validated by neurologists who reviewed their records in detail.

The reasons for the ethnic and gender differences seen in the new study are unclear, because the researchers were able to account and adjust for blood pressure, age, excessive alcohol use, smoking and health insurance status.

In all, 40 percent of the 107 SAH cases were in non-Hispanic whites, although 52 percent of the over-45 population in the study area is non-Hispanic white. Meanwhile, 60 percent of the SAH cases occurred in Mexican Americans, who make up 48 percent of the population over age 45 in the study area.

At the same time, 67.3 percent of SAH patients were women, though 53.5 percent of the population in the area is female. The researchers found that Mexican American women had the highest risk.

Subarachoid hemorrhages account for 3 percent of the 780,000 strokes that occur in the United States each year. Because these strokes arise from ruptured aneurysms, which are weak bulging spots in the brain's blood vessels that arise for unknown reasons at any stage of life, subarachnoid hemorrhages can occur at any time of life.