News Release

Wake Up To Stroke -- Night Strokes Linked To Long Delays In Care

Peer-Reviewed Publication

American Heart Association

ORLANDO, Fla. March 25 -- A person who has a stroke during the night waits four to seven hours longer to seek emergency treatment than someone whose stroke occurs during the day, researchers report today at the American Heart Association meeting on epidemiology and prevention.

North Carolina researcher Wayne Rosamond, Ph.D., who presented the study, says, "The type of treatment a stroke patient receives is partially determined by the length of time since the stroke began. When a stroke starts during sleep, the person may only be aware of symptoms after he or she awakens. The exact time of onset is difficult to pinpoint and the physician can only assume that the stroke started soon after the individual went to sleep. This, of course, means that the delay time is longer than if we knew the exact moment of onset. Without a better way of pinpointing the onset of nighttime strokes, we have limited potential to treat these patients with thrombolytic drugs."

Just a few years ago, few treatments for stroke existed, but now clot-busters -- or thrombolytics -- can dissolve the clots that cause most strokes and thus prevent brain damage, says Rosamond, assistant professor of epidemiology at the University of North Carolina, Chapel Hill.

The researchers looked at the reasons for delays in treatment of patients with ischemic stroke, the most common type of stroke, which occurs when blood flow is impeded by a blocked artery in the brain. Stroke is the No. 3 cause of death and a major cause of disability in the United States. About 600,000 strokes occur each year, 160,000 of which are fatal.

In the study, 559 patients with stroke-like symptoms were questioned upon arrival at hospital emergency departments in North Carolina, South Carolina and Colorado about when their symptoms first occurred. If the symptoms were present when the person awoke, the individual was asked to reveal the last time he or she was free of symptoms.

To investigate a spectrum of health environments, the researchers studied patients in the Carolinas, where death rates from stroke are twice the national average, and in Colorado, where stroke death rates are much lower.

Researchers found that one-third of patients noticed stroke symptoms upon awakening. When the onset of stroke occurred between 10 p.m. and 2 a.m., up to 11 hours passed before the patient arrived at the hospital. Individuals whose symptoms occurred between noon and 4 p.m. delayed arriving at the hospital by only 2.5 hours. The median time of arrival at the hospital was 5.5 hours for those who awoke with symptoms, compared to 2.5 hours for those whose symptoms first appeared while awake.

Regardless of when the stroke occurred, more than one-half of all patients took more than four hours after the onset of symptoms to arrive at the hospital.

"Clot-busting drugs must be given within three hours of the onset of symptoms to be effective at all," says Rosamond. "Fifty percent don't even get to the hospital within four hours. Then you must add in the time it takes for evaluation and diagnostic tests, like a computer tomography scan, to allow physicians to determine if the stroke should be treated with a clot-buster. Strokes caused by bleeding in the brain -- hemorrhagic strokes -- are not treated with clot busters, because the drugs can increase the bleeding which can lead to death.

"A substantial proportion of patients are asleep when the symptoms occur," says Rosamond. "When that happens, their delay time in getting to the hospital is much longer, since the last time they were known to be symptom free might have been when they went to bed, making identification of the exact time of onset difficult. We need to find a way for people to understand stroke symptoms and treat them as a dire emergency so they will get to the hospital sooner, and we need to find new ways to improve care for the one-third of patients who awaken with symptoms of stroke."

For those individuals, it is likely that the symptoms don't awaken them. This is understandable, because the symptoms of stroke are subtler than those of heart attacks. Stroke symptoms include sudden weakness and numbness in the face, arm or leg on one side of the body and sudden dimness or loss of vision or speech, particularly in one eye. Other symptoms include sudden confusion, trouble speaking or understanding, sudden trouble walking, dizziness, loss of balance or coordination, and sudden severe headache with no known cause.

"This study underscores the importance of seeking help when symptoms first start," he says. "We need to educate people to recognize the symptoms of stroke, to appropriately interpret the symptoms as a stroke and to call 911 immediately when they occur."

Co-authors are Dexter Morris, M.D., Ph.D., Kelly Evenson, Ph.D., Jeffrey Vallee and Kristie Schmidt, University of North Carolina, Chapel Hill, and Suzanne Cook, Ph.D., GlaxoWellcome, Inc., North Carolina.

The research was presented at the American Heart Association 39th Annual Conference on Cardiovascular Disease Epidemiology and Prevention.

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Media advisory: Dr. Rosamond can be reached by calling 919-962-3230. (Please do not publish telephone number.)



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