Brain Scans Probe the Limits of Consciousness

(Credit: sfam_photo/Shutterstock) New research from scientists at the University of Copenhagen and Yale University may offer a simple, yet powerful way to pull back the curtain on the true status of patients in a coma. Using a type of Positron Emission Tomography (PET) scanning, the researchers say they were able to predict with 94 percent accuracy whether a coma patient would wake up. Typically, determining who will emerge from a coma is based on a doctor's bedside exam, and they often make mistakes. They measured patients' brain activity using a specialized camera that detected emissions from a radioactive glucose analogue that was introduced into their brains. Glucose is what the brain gets its energy from — literally brain food — and by observing how much of the glucose was metabolized in the brain, the researchers were able to see how active the brain actually was.