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'Vegetative' Woman's Brain Shows Surprising Activity
"I'm quite confident that [Schiavo] would not have responded in this way," said James L. Bernat, a neurologist at Dartmouth Medical School. But, he said, the findings indicate that current methods of evaluating awareness are unreliable.
"It's a little disturbing," Bernat said. "This suggests there may be things going on inside people's minds that we can't assess by interacting with them at the bedside."
Some experts said the findings are compelling enough that patients should be routinely assessed this way.
"If it was a relative of mine, I know I'd demand it," said John Connolly, a University of Montreal neuroscientist.
Others said that is premature.
"We have to be exquisitely cautious. We don't want to raise false hopes. This is very new technology," said Kenneth W. Goodman, a University of Miami bioethicist. "We don't really know what parts of your brain lighting up really mean."
An estimated 25,000 Americans are in a vegetative state, and more than 100,000 are believed to be in a related condition known as "minimally conscious," in which they exhibit impaired or intermittent awareness.
Owen stressed that the test could never rule out the possibility that patients have some awareness because even healthy people sometimes show no response on the scan.
The findings follow recent studies by Schiff and others that suggest some brain injury patients may be more responsive than anyone realized. And scientists have long known that patients in a vegetative state sometimes regain at least some awareness. Those who had a blow to the head generally have better prospects than those whose brains were oxygen-deprived because their hearts stopped.
The 23-year-old patient in Britain, whose name and other personal details were withheld, suffered head trauma in a July 2005 traffic accident that left her in a coma. After about two weeks, she opened her eyes and started going through cycles of being asleep and awake. But she had no ability to communicate, and repeated tests over more than five months found no signs of awareness or consciousness, leading doctors to diagnose her as being in a vegetative state.
But then Owen and his colleagues began a series of tests on the woman at the University of Cambridge using functional magnetic resonance imaging, which can detect different types of mental activity by measuring blood flow to various parts of the brain.
The key tests were experiments in which the researchers asked her 20 times to envision herself playing tennis and exploring her house. Brain regions involved in language, movement and navigation, which would be active when someone was playing tennis, wandering around a building, or imagining doing so, lighted up in ways that were "indistinguishable" from those in 12 healthy people.
The findings show that the woman "retained the ability to understand spoken commands and to respond to them through her brain activity, rather than through speech or movement," the researchers wrote. "Her decision to cooperate . . . by imagining particular tasks when asked to do so represents a clear act of intention, which confirmed beyond any doubt that she was consciously aware of herself and her surroundings."
"It was an absolutely stunning result," Owen added in a telephone interview.
About six months later, during follow-up testing, the woman appeared to follow a mirror to the right with her eyes. But that was the last hint of awareness, and her future remains unclear.
"Whether she has a life of the mind is a question that is incredibly provocative and important," said Joseph J. Fins, a bioethicist at Weill Cornell Medical School. "What we may be seeing perhaps is a window into the recovery of consciousness. But we just can't answer that at this point."