New anti-stroke treatment must be delivered quickly

On Call

July 30, 1996|By Dr. Simeon Margolis | Dr. Simeon Margolis,SPECIAL TO THE SUN

I don't understand why we have to rush people to the hospital at the first sign of stroke when it is my understanding that there is no real treatment for stroke.

In mid-June, the Food and Drug Administration approved the use of a genetically engineered form of a natural clot buster called t-PA (tissue plasminogen activator) for the emergency treatment acute ischemic strokes, or about 80 percent of all strokes.

The drug dissolves clots blocking blood flow to the brain in the same way it has been used effectively for several years for the acute treatment of heart attacks.

The need for quick hospitalization is made clear by studies showing that t-PA treatment must be started within three hours of the onset of the stroke to get the most benefit. Because t-PA increases the danger of intracranial bleeding, a CT scan must be done before the drug is administered to be sure the patient has not suffered a hemorrhagic stroke (due to bleeding into or around the brain).

The results of a five-year study published in the New England Journal of Medicine in December 1995 showed that, compared to those treated with a placebo, patients given t-PA were "at least 30 percent more likely to have minimal or no disability" three months after the stroke.

Bleeding is a serious threat, however, although on average, patients who bleed into the brain had evidence of more severe brain damage before any treatment was started. The number of deaths was the same in the two groups at the end of three months.

Treatment with t-PA is likely to be an important advance in overcoming the understandably pessimistic attitude of patients and doctors toward stroke outcome, particularly after future studies better define the optimal dose and which patients are least likely to have a bleeding complication.

The results of another recent study raise the hope that stroke victims may benefit from another type of rapid treatment. When an artery in the brain is blocked in animals, brain cells supplied by the artery are surrounded by high concentrations of the amino acid glutamate, which damages brain cells (neurons) by overexciting them. When 193 patients were treated with a placebo or a small dose of lubeluzole, which prevents the increase in glutamate outside of cells, within six hours of an ischemic stroke, the death rates after 28 days were 18 percent in the placebo group and only 6 percent in those given the small dose of lubeluzole. More clinical trials will be required before this drug might become available for general use.

Dr. Margolis is professor of medicine and biological chemistry at the Johns Hopkins School of Medicine.

Pub Date: 7/30/96

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