Public Release: 

Study On Aneurysm Formation Points To Enzyme Activity

Lerner Research Institute

September 3, 1996

CONTACTS: Rob Whitehouse, 216/444-8927
Jim Armstrong, 216/444-9455


MUNICH, Germany -- A Cleveland Clinic study presented today at an international stroke conference raises hope that doctors soon will be able to predict if a person is at risk for developing a brain aneurysm.

Douglas Chyatte, M.D., head of Cerebrovascular Surgery at The Cleveland Clinic, said the study of 31 aneurysm patients showed a three-fold increase of activity involving an enzyme called gelatinase. The enzyme, he said, is responsible for breaking down the structural proteins in brain arteries, thus weakening the wall of the arteries.

An aneurysm is a bubble-like defect in the walls of arteries, much like a bulge in a garden hose. In the brain, an aneurysm can cause severe headaches, or it can rupture, resulting in a stroke or even death. Aneurysms affect about 2 percent of the U.S. population.

"Right now, medical science doesn't understand the mechanisms behind aneurysm formation, so there is no way to predict when one will occur," said Dr. Chyatte, who spoke at the Joint World Stroke Congress and European Stroke Conference in Munich. "And, since there are no symptoms prior to the formation of an aneurysm, most patients don't know it's there until it ruptures. One-third of them don't survive long enough to receive medical treatment."

Dr. Chyatte studied 31 patients, some whose aneurysms had ruptured and some whose had not. Both groups of patients showed a significant increase in gelatinase activity. Slides comparing brain arteries in healthy individuals to those in aneurysm patients clearly indicate smaller, weakened reticular fibers in the aneurysm group.

"This is the first insight into why aneurysms occur," said Dr. Chyatte. "Although more studies need to be conducted, this could lead to a predictive test for aneurysms and, ultimately, a preventive therapy."

Celebrating 75 years of world-class care, The Cleveland Clinic Foundation continues to advance the frontiers of medicine by providing state-of-the-art care in a multispecialty academic medical center model. Since its founding in 1921, clinical and hospital care have been integrated with research and education in a private, non-profit group practice which has distinguished The Cleveland Clinic in American medicine. Today at The Cleveland Clinic and Cleveland Clinic Florida, nearly 700 full-time, salaried physicians represent more than 100 medical specialties and subspecialties. Every year, The Cleveland Clinic and Cleveland Clinic Florida provide for more than 993,000 outpatient visits and 41,000 hospital admissions from throughout the United States and more than 80 countries. In 1995, The Cleveland Clinic and Marymount Hospital, a non-profit 279-bed acute-care community hospital, merged.

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