The most common type of stroke is ischemic stroke, which results from an artery blockage that prevents blood from reaching part of the brain. Hemorrhagic strokes are less common, accounting for 10 percent to 20 percent of all strokes.
Subarachnoid hemorrhage (SAH), which accounts for about 7 percent of strokes, occurs on the surface of the brain and usually results from a ruptured intracranial aneurysm, a blood vessel in the brain that suddenly bursts.
These are not subtle strokes, says Brett M. Kissela, M.D., lead author of one of the papers and an assistant professor of neurology at the University of Cincinnati in Ohio. They are usually painful and generally quite devastating and nearly 40 percent of the people who get them die within 30 days.
These strokes generally happen in young people, which means they die at an early age or lose decades of useful life because they are unable to work, Kissela says.
The study included 107 individuals with SAH and 197 without stroke who were participants in the Genetic and Environmental Risk Factors and Hemorrhagic Stroke Study, conducted by the University of Cincinnati College of Medicine. Participants came from Ohio and Kentucky hospitals within a 50-mile radius of the medical school.
Heavy alcohol users had more than a 10-fold increased risk of SAH compared to non-drinkers. Other important factors included hypertension (high blood pressure), smoking and having a relative with SAH.
Previous studies have yielded conflicting findings regarding the role of hypertension in SAH. However, Kissela and his colleagues found a strong association between the two.