Yamada and colleagues tested the helmet on patients (average age 68) three to 12 hours after stroke onset. The helmet was attached to the head and neck. The cooling of the head continued non-stop for three to seven days without anesthesia.
Researchers evaluated functional outcome three to 10 months after stroke. The surface cooling was performed successfully in all patients.
Tympanic temperature, which measures surface brain temperature, was lowered 4.0 degrees Fahrenheit and jugular temperature, which reflects deep brain temperature, was lowered 1.4 degrees Fahrenheit. In hypothermia with a helmet, such a temperature gradient in the brain results because of the local nature of the cooling method, Yamada said.
Some patients experienced mild shivering, elevated potassium levels, mild skin damage and infections, but none had serious adverse effects.
After 10 months of follow-up, only one patient (6 percent) had died. Six patients (35 percent) had "good" functional outcome three to 10 months after stroke.
The American study evaluated patients average age 68 and used liquid cooling technology developed by NASA scientist William Elkins, "father of the American spacesuit," Wang said.
In animal studies, researchers have determined that cooling the brain can reduce the damage that stroke does to the brain tissue by as much as 70 percent, Wang said. "The goal with this therapy, therefore, is to try to improve neurological outcomes by minimizing stroke's effect," Wang said. "The first step in that direction was to find a therapy that effectively cooled the brain and, judging by this study, we have."
In this study, researchers gauged brain temperature via tiny fiberoptic probes inserted in the brain. These probes are often used t
Contact: Carole Bullock
American Heart Association