EMBARGOED FOR RELEASE UNTIL 4 PM ET, May 26, 2003
Drug May Work on Secondary Clots in Stroke
St. Paul, Minn. – Many stroke patients can be treated with clot-busting drugs to reduce their chances of death and disability. But for some patients, the treatment is unsuccessful because the clots reappear soon after treatment. Now researchers have identified a drug that can break up those secondary clots, according to a study in the May 27 issue of Neurology, the scientific journal of the American Academy of Neurology. The study examined 18 patients who successfully underwent thrombolytic treatment for stroke caused by blood clots or other blockages of the arteries leading to the brain. In four of the patients, or 22 percent, blood clots formed again within 20 minutes after the arteries were clear. Those four patients were given the drug abciximab, a blood-thinner that prevents blood particles known as platelets from clumping or forming clots. The drug broke up the clots in all four patients. Three patients showed marked improvement in symptoms resulting from the stroke. “After major strokes and severe clinical deficits, these patients had dramatic improvements,” said study author and neurologist Ji Hoe Heo, MD, PhD, of Yonsei University in Seoul, Korea. “Two had no symptoms and one had minor symptoms that did not interfere with his lifestyle. All three fully regained their previous activities and jobs.” One patient had a small hemorrhage and made slight improvements. Heo said the relative lack of improvement is likely not due to the hemorrhage, which is a risk of thrombolytic drugs. “We believe that he avoided a larger stroke with the treatment, but unfortunately the stroke affected the area of the brain that plays a critical role in motor functioning.” Heo said it’s too early to say that abciximab is entirely safe for stroke patients because the number of patients in the study was small. “This study is promising, because it suggests that these secondary clots may occur often and provides evidence that abciximab may be beneficial for treating them,” Heo said. “This could significantly improve the success rate of thrombolytic therapy.” The researchers measured the arteries of 17 of the patients after the thrombolytic therapy was given. The arteries of the four patients who had the secondary blood clots were significantly narrower, on average, than those of the people who did not develop secondary blood clots. The arteries of the four patients were more than 50 percent obstructed, Heo said. Obstructions and narrowing of the arteries can lead to heart attack and stroke. The arteries of three patients were measured again after treatment with abciximab. The arteries in two patients had no more narrowing, and the artery in one patient was much improved. The thrombolytic therapy the four patients received was tissue plasminogen activator (t-PA) combined with urokinase. Heo noted that for stroke patients to be treated with thrombolytic therapy, they must get to a hospital quickly so treatment can start within a few hours after symptoms begin. “Stroke must be treated as the life-threatening emergency that it is,” Heo said. “If you notice any of the signs of stroke in another person or yourself, call 911 immediately.” Stroke symptoms are: * Sudden numbness or weakness of the face, arm or leg, especially on one side of the body * Sudden confusion, trouble speaking or understanding * Sudden trouble seeing in one or both eyes * Sudden trouble walking, dizziness, loss of balance or coordination * Sudden severe headache with no known cause The study was supported by a grant from the Korean Ministry of Health & Welfare.
The American Academy of Neurology is the world's largest association of neurologists and neuroscience professionals, with 32,000 members. The AAN is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer's disease, stroke, migraine, multiple sclerosis, concussion, Parkinson's disease and epilepsy.