Brain damage from stroke reduced by 'cool' therapy

DALLAS (CNN) -- Lowering the body's temperature by even 1 degree within a few hours of a stroke can reduce brain damage and the risk of death, according to a new study.

Reporting in this month's Stroke, one of the journals of the American Heart Association, researchers in Copenhagen, Denmark, induced mild hypothermia in 17 patients soon after they suffered strokes, maintaining the cooler body temperature for about six hours.

"The brain receives cooled blood," explained Dr. Lars Kammersgaard, the study's lead author. "Animal studies involving hypothermia strongly suggest that decreased brain temperature causes less destruction of brain tissue."

In fact, patients receiving cooling therapy had a six-month survival rate of nearly twice that of other patients who didn't get the hypothermia treatment.

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"Cooling the brain is sort of putting it down to sleep a little bit," said Dr. Camilo Gomez of the University of Alabama's Comprehensive Stroke Center in Birmingham. The stroke center did not participate in the Danish research, but is also studying the technique.

"Essentially, we have two cooling blankets," said Gomez. "And what we do is put one on the bottom of the patient, and we have one on top."

Danish researchers also used cooling blankets by pumping cooled air into a thermal blanket. The Danish study was the first to investigate the effectiveness of the therapy on conscious patients.

Using hypothermia for stroke patients is still considered experimental.

In Alabama, doctors treated Cleo Medders after he suffered a major stroke four years ago. His body temperature was lowered by 4 degrees for about a day.

"They took him to intensive care and ... his brain filled with blood, and I know they iced him," said Medders' wife, Mary.

Medders doesn't remember the cold himself. He was unconscious during treatment. But he believes it saved his life.

"I wouldn't even be here," he said. "It's a miracle."

Before the Danish study, Kammersgaard said, only a few patients had been treated with hypothermia therapy -- all of them while unconscious. But researchers in Copenhagen used a drug to control shivering so they could keep the 17 patients in the study awake.

On average, body temperatures were lowered by 1.3 degrees, and some reduction continued for up to four hours. Six months later, some 12 percent of the cooled patients had died, compared to 23 percent of the stroke patients who had not been chilled.

None of the cooled patients experienced side effects serious enough to withdraw from the study, researchers wrote, noting that "in general, the method appeared to be well tolerated."

Previous studies using greater degrees of hypothermia treatment resulted in about a 40 percent incidence of pneumonia, but overall survival rates were still promising, Kammersgaard's group wrote.

"By showing that hypothermia can be successfully used without anesthesia, we have suggested a method of treatment that appears to be low in cost and applicable in most hospitals involved in stroke treatment," Kammersgaard said. "If future trials support our findings, the majority of stroke patients may be able to benefit from this treatment in the near future."

Larger scale studies must be done to distinguish whether cooling therapy has any effect on degree of paralysis and other deficits caused by stroke, the Danish researchers said.

In Alabama, Gomez and his colleagues are working toward the same goal.

Stroke, also known as a "brain attack," is the third leading cause of death in the United States. But it is the No. 1 cause of disabling injury.

CNN Medical Correspondent Rhonda Rowland contributed to this report.

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Cause and treatment of strokes
August 2, 2000
Medical experts urge 'stroke centers' for hospitals
June 20, 2000

American Stroke Association
Stroke Journal
Comprehensive Stroke Center, University of Alabama

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