By Rob Stein
Washington Post Staff Writer
Friday, September 8, 2006
According to all the tests, the young woman was deep in a "vegetative state" -- completely unresponsive and unaware of her surroundings. But then a team of scientists decided to do an unprecedented experiment, employing sophisticated technology to try to peer behind the veil of her brain injury for any signs of conscious awareness.
Without any hint that she might have a sense of what was happening, the researchers put the woman in a scanner that detects brain activity and told her that in a few minutes they would say the word "tennis," signaling her to imagine she was serving, volleying and chasing down balls. When they did, the neurologists were shocked to see her brain "light up" exactly as an uninjured person's would. It happened again and again. And the doctors got the same result when they repeatedly cued her to picture herself wandering, room to room, through her own home.
"I was absolutely stunned," said Adrian M. Owen, a British neurologist who led the team reporting the case in today's issue of the journal Science. "We had no idea whether she would understand our instructions. But this showed that she is aware."
While cautioning that the study involved just one patient who had been in a vegetative state for a relatively short time, the researchers said it could force a rethinking of how medicine evaluates brain-damaged patients.
"We have found a method for determining if a patient is aware," Owen said. "It provides us with a tool that may be able to help make difficult decisions about these patients."
Other researchers were cautious but praised the research as groundbreaking with potentially profound implications. The work could lead to crucial new insights into human consciousness, one of the most daunting scientific mysteries, and to new ways to improve the diagnosis and treatment of tens of thousands of brain injury patients.
"This is a very important study," said Nicholas D. Schiff, a neurologist at the Weill Cornell Medical College in New York. "It's the first time we've ever seen something like this. It really is kind of shocking."
But Schiff and others stressed that much more work is needed.
"It raises a lot of questions," Schiff said. "At what level is she conscious? Is she really imagining she is playing tennis? Is it possible to communicate with this person? At this point, this doesn't allow us to make any inference about where this patient's consciousness might be."
The research inevitably renewed questions about patients such as Terri Schiavo, the Florida woman in a persistent vegetative state whose family dispute over whether to discontinue her care ignited a national debate over the right-to-die issue. Schiavo's brother, Bobby Schindler, said the study underscores the uncertainties in diagnosing brain injury patients.
"Things are changing almost every day with what they're finding out about the brain," he said. "The technology they're creating could help people like my sister."
But Owen, Schiff and others stressed that the research does not indicate that many patients in vegetative states are necessarily aware or likely to recover. Schiavo, in particular, had suffered much more massive brain damage for far longer than the patient in Britain, making awareness or recovery impossible, they said.
"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."