A new study will help physicians decide how to treat individuals with unruptured intracranial aneurysms (UIAs). The study, reported in the December 10, 1998, issue of The New England Journal of Medicine, found that the size and location of the aneurysm in the brain, as well as the patient's medical history, are the best predictors of future rupture.
"This study gives us more data on which to base treatment decisions for patients with unruptured intracranial aneurysms," says John R. Marler, M.D., a neurologist with the Division of Stroke, Trauma, and Neurodegenerative Disorders at the National Institute of Neurological Disorders and Stroke (NINDS), sponsor of the study and part of the National Institutes of Health, located in Bethesda, Maryland.
An aneurysm is a weak spot on an artery wall that balloons out due to pressure from the blood. When a brain aneurysm bursts, it releases blood into the spaces of the brain, causing a hemorrhagic stroke. Although hemorrhagic strokes account for only about 20 percent of all strokes, they are much more severe than other strokes and are fatal more than 50 percent of the time. The standard treatment for UIAs at risk for rupture is surgery. But surgery to remove an aneurysm carries its own health risks, including stroke or infection that can lead to impaired mental ability, brain damage, or even death. Perhaps as many as 10-15 million Americans may have intracranial aneurysms at some point in their lifetimes. In contrast, the number of people who have a first subarachnoid hemorrhage, a specific type of brain hemorrhage, is low, only about 10 people in 100,000 per year. This means that most intracranial aneurysms do not rupture.
"Historically, there has been little if any consensus on the issue of which
aneurysms needed to be treated and which could be left alone and monitored,"
says David O. Wiebers, M.D., Chair of the Division of Cerebrovascular Diseases
at the Mayo Clinic in Rochester, Minn
Contact: Marcia Vital
NIH/National Institute of Neurological Disorders and Stroke