Stroke alert: Know the signs of a stroke

Benefits of early detection
Dr. Frank Silver, a neurologist and director of the stroke program at Toronto's University Health Network, finds it heartbreaking when people having a stroke come in too late to receive the most effective treatment. There are drugs available today that can stop stroke in its tracks, but they must be delivered very early, ideally within three hours of the onset of stroke symptoms. After that it's a matter of diminishing returns, which is why Silver wants all Canadians to be aware of the warning signs and symptoms of stroke and to call emergency services as soon as they experience any of them.

The introduction in 1996 of a clot-busting drug, tissue plasminogen activator (tPA), has transformed stroke treatment, says Silver. Where once there was despair, now there is hope. “In the pre-tPA days, effective stroke care was nonexistent. Stroke was an emergency, but one that we could do little about,” he says. With tPA, neurologists now have an effective treatment for the most common type of stroke. Ischemic strokes, caused by clots in the blood vessels in the brain, account for 80 per cent of all strokes. A naturally occurring clot-dissolving substance, tPA, can be administered intravenously to hasten the opening of the blood vessel that is blocked with the clot.

Different detection methods
Silver still marvels at the effect of treatment with tPA. “With modern brain imaging, you can look at the area in the brain where the clot has formed and it's like looking at a tree where the branches have been removed. Then you deliver the treatment and suddenly all the branches and leaves reappear,” he says. “And then, after that, to see a patient lift a previously paralyzed arm or begin to speak is very, very dramatic. Of course, it doesn't work that well in every case, but there are some truly excellent results. And 30 per cent of the time patients improve who would not have improved without therapy.”

But tPA is not for every stroke patient. At least 20 per cent of strokes are hemorrhagic, caused by bleeding in the brain. For people with this type of stroke, tPA treatment could be a death sentence because its clot-busting effect would increase the severity of the bleeding. Effective treatment for these patients may involve using surgery to clip off a leaky blood vessel or endovascular treatment (advancing tubes and devices through the body inside the blood vessels) to obliterate the bleeding site with detachable coils. Therefore, before any treatment can be administered, a CT (brain) scan is vital to determine the type of stroke. And all of this must be done within the first few hours of the stroke.

Planning a strategy
But in difficulty there is sometimes opportunity. In 1997 the Heart and Stroke Foundation of Ontario and the province's neurological community sat down to plan a coordinated stroke strategy.

“In partnership with the provincial government, we eventually developed a system of stroke-care delivery across the province, including regional stroke-care centres,” says Bev Powell-Linden, the manager of stroke-care delivery for the Heart and Stroke Foundation of Ontario. “Neurologists, neurosurgeons and many other stroke-care providers work as a team at these centres to provide the best possible care to patients and their families. All paramedics and emergency personnel are trained to identify patients who are having a stroke and get them to the nearest stroke centre as fast as possible.”

Page 2 of 5