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Nowhere is that complexity more evident than in our understanding of how consciousness works--and fails to work. Minor accidents like Filipov's can lay waste to cognitive processes. Major traumas like the shooting wounds of Congresswoman Gabrielle Giffords can leave remarkable room for recovery. Patients labeled vegetative typically stay that way--but sometimes they don't. So where's the line between resignation and hope? Various studies in the past decade, including one by Belgian and U.S. experts in 2009, have found that about 40% of patients diagnosed as vegetative are actually conscious and fall into a category adopted in 2002 called minimally conscious, a state in which some awareness exists and improvement is possible.
In the Nov. 10 issue of the medical journal the Lancet, a research team that included Laureys illustrated this point starkly. They studied 16 patients diagnosed as vegetative, hooking them up to an electroencephalogram (EEG) and asking them to imagine squeezing their right hand and wiggling their toes on command. Three of the subjects apparently imagined it well, with the proper EEG tracings appearing in the premotor cortex of their brain. Did they hear? Were they conscious?
Those are terrifying questions. Patients wrongly diagnosed as vegetative are sentenced to a life of being tended to by caregivers (who may never take the trouble to engage them because it seems pointless) even as a partly functioning mind weeps or dreams or rages within. "The notion of a conscious person treated as not conscious--to me that's the ultimate portrait of isolation," says Dr. Joseph Fins, chief of medical ethics at Weill Cornell Medical College in New York City. "It's solitary confinement of the most troubling kind." The Lancet study and others suggest that with the right technologies and therapies, at least some of these confined minds may conceivably be set free.
A Look in the Mirror
Each year in the U.S. at least 14,000 victims of brain damage are diagnosed as vegetative. If the 40% misdiagnosis figure is correct, that means 5,600 of them are in better shape--perhaps far better--than their records show.
There are a lot of reasons the error rate is so high, not least that truly reliable tests for consciousness have not been developed. To date, the only accepted diagnostic method remains a bedside exam. Clinicians ask patients to respond to commands like "Squeeze my hand" and "Look at the ball." But many postcoma patients suffer from aphasia, the inability to understand language. Brain damage may leave other patients deaf or blind or so severely spastic, epileptic or paralyzed that they cannot control their movements. They may be severely amnesiac and unable to remember what is asked of them. They may suffer from akinetic mutism, in which the part of the brain responsible for decisionmaking and drive is damaged.