Signaling loop in healthier subjects is broken for patients in vegetative state
Talk between the brain’s decision-making center, or frontal cortex, and other brain regions might distinguish aware individuals from those stripped of conscious thought. Identifying such signaling malfunctions could speed the diagnosis of vegetative states and give scientists insight into such devastating disorders, an international team of researchers reports May 12 in Science.
Today, diagnosing a vegetative brain is an uncertain enterprise, says John Whyte, director of the Moss Rehabilitation Research Institute in Elkins Park, Pa. Patients classified as vegetative can’t act in any purposeful way under any observable circumstances. Patients deemed minimally conscious, however, show some capacity to understand and interact with the world — for instance, by moving a finger on command. Distinguishing between the two can take weeks of behavioral testing, and misdiagnoses are common.