Researchers say they can predict awareness and return to consciousness of comatose patients

Researchers have developed a new method to peer into a comatose patient’s brain. By measuring how much sugar a brain consumes, scientists are able to predict a patient’s current state of awareness and the chance that the patient will regain consciousness within a year, according to a study published in the journal Current Biology.

A research team from the University of Copenhagen in Denmark and the University of Liège in Belgium sought a more dependable laboratory analysis that would accompany clinical examinations to determine a patient’s current and future level of awareness. They administered, mapped, and measured sugar as a marker in 131 brain-injured patients, and found that the brain’s glucose metabolism strongly correlated with behavioral responsiveness. The researchers were able to predict consciousness or return to consciousness in 94 percent of cases.

“In nearly all cases, whole-brain energy turnover directly predicted either the current level of awareness or its subsequent recovery,” Ron Kupers of the University of Copenhagen and Yale University said in a press release. “In short, our findings indicate that there is a minimal energetic requirement for sustained consciousness to arise after brain injury.”

Patients whose glucose metabolism measured under a threshold of 42 percent of normal appeared unconscious and failed to recover consciousness within the following year. Meanwhile, patients whose glucose metabolism measured above 42 percent the threshold had signs of initial responsiveness or recovered responsiveness within a year.

“The take-home message [for now] is that consciousness is a highly energy demanding process, involving the brain at large,” Kupers said. “This fundamental physiological trait can help clinicians determine the potential for recovery of awareness in patients suffering from severe brain injuries of any kind.”

Kupers and his team still insist that their findings need to be verified by an independent study. However, their research opens interest in further investigating how awareness relates to brain metabolism and how brain metabolism may change over time in brain-injured patients.