Acoustic test may signal coma recovery

Science News : The progression over time of a comatose brain’s ability to distinguish sound patterns appears to be linked to the likelihood that the patient will eventually awaken. Marzia De Lucia of the University of Lausanne in Switzerland and her team studied 30 coma patients who had suffered heart attacks. For the first 24 hours, all of the patients underwent standard therapeutic hypothermia to prevent brain damage. During that time, De Lucia played various sounds and recorded the patients’ brain activity. All 30 of the patients’ brains showed the ability to discriminate between the sounds. The next day, after the therapeutic hypothermia was finished, the patients were tested again. Over the next three months, all of the patients whose brains showed improved sound discrimination had woken up. Of the patients who did not improve, many died. De Lucia believes that the progression of the ability to distinguish sounds is a clear predictor of likelihood of survival. Her team is now repeating the test on a larger population of patients, and hopes that their study may help doctors provide more timely treatment for coma patients.