A new way to keep stroke patients cool might help them survive the ordeal with less brain damage, according to a small clinical trial. If the results pan out in larger studies, they could offer a cheap and desperately needed alternative therapy to improve the odds of a good recovery.
Stroke is the third most common cause of death in the United States and the leading cause of disability. When a blood vessel becomes clogged or bursts, parts of the brain lose oxygen and die. Researchers have developed drugs that diminish the brain damage in animals--but the drugs haven't helped much in humans. Another approach was inspired in part by an unexpected 1996 observation. Stroke patients who had slightly cooler body temperatures when they were admitted to a hospital were up to 80% more likely to be alive after 6 months. That, along with animal studies showing that cool body temperatures minimized stroke damage, "encouraged us to try intervening," says neurologist Lars Kammersgaard of the Genofte University Hospital in Copenhagen, Denmark.
Kammersgaard's team devised a special blanket that pumps out air at 10 degrees Celsius. They wrapped 17 stroke patients in the blankets and gave them a drug to stop them from shivering, which warms the body. The dual treatment safely cooled the bodies of the stroke victims 1.5 degrees Celsius in 6 hours, the researchers report in the September issue of the journal Stroke. The study was too small to reveal whether the cooling helped the patients recovery. More patients who were treated with the blanket were still alive after 6 months compared to patients who maintained normal body temperatures, and the chilled patients had somewhat less brain damage, although the differences weren't statistically significant. To follow up, the team is planning to lead a large clinical trial called the Nordic Cooling Project, which might begin accepting patients by the end of the year.
Other experts like what they see so far. "There's a possibility it could work in the clinic," says neuroscientist Thomas Sick of the University of Miami School of Medicine. But he cautions that it might be better to come up with a way to cool the brain without cooling the entire body, which could reduce the blood supply to organs and lead to dangerous blood clots. Still, says stroke researcher Dale Corbett of the Memorial University in St. Johns, Newfoundland, "there's enough here to suggest that a larger trial should be undertaken."