They sleep, sometimes snore, and regularly open their eyes, but patients in a vegetative state appear to be completely unaware of the world around them. Are they?
That's the question that drives celebrated British researcher Adrian Owen, who is moving to Canada in December and bringing five of his colleagues with him. He has pioneered a new way to communicate with seemingly unconscious patients by putting them in a brain imager and asking them to think particular kinds of thoughts.
"We keep finding patients who aren't what they appear to be," Dr. Owen said. "They've been residing in nursing homes for years on end. But put them in a scanner and suddenly they can imagine playing tennis."
Dr. Owen's arrival at the University of Western Ontario will put Canada at the heart of an international effort to develop a new, standard protocol to identify patients who, while appearing to be unconscious, are living the nightmare of being trapped in their bodies with no ability to communicate. These patients are rare, but an estimated 40 per cent of them have been misdiagnosed and are actually conscious at least some of the time.
The work could also lead to new treatments, like drugs or deep brain stimulation with electrical currents, to help unconscious patients regain brain function. In addition, Dr. Owen is planning to broaden the scope of his work to include patients in comas, who are out cold and don't open their eyes.
Lured to Canada as part of a $200-million federal effort to recruit 19 superstar researchers, Dr. Owen is best known for a breakthrough reported earlier this year. He led a team of scientists that showed some patients deemed to be in vegetative state could answer yes-or-no questions by thinking of either playing tennis or walking through their house. A functional magnetic resonance imager allowed the researchers to monitor what happened in their brains. Their scans looked the same as those of healthy volunteers who were asked to imagine that they are returning a serve or rushing the net.
Many vegetative patients couldn't do it; there was no sign of conscious thought. But others, including a young man who doctors had presumed to be in vegetative state for five years after a 2003 car accident, were able to reconnect with the world.
Often they have had a traumatic brain injury or suffered a cardiac arrest that starved their brains of oxygen and were in comas for a number of weeks before they opened their eyes.
The diagnosis that someone is in a vegetative state is a difficult one, and is based on how patients respond to sounds, touch and other stimuli. But what if they can't move, talk or make any kind of noise?
Brain imaging is one new tool to assess these patients, but Dr. Owen is determined to develop cheaper and easier ways to find out if someone is "in there," and to communicate with them if they are.
These techniques could also offer glimpses into what's happening inside the brains of coma patients.
"Exactly the same sort of things might apply in comas as we have been finding in vegetative state," Dr. Owen said. "Some people are going to say it is never going to work, but they said the same thing about vegetative state. It could well work."
Researchers in London are already studying brain activity in comatose patients and recently reported the results of an intriguing experiment that involved one of their colleagues, research scientist Fred Possmayer.
He had a heart attack while playing tennis four years ago and was still unconscious by the time he was wheeled into the emergency room. Doctors were able to restart his heart, but he remained in a coma for three days.
During that time, neuroscientist Bryan Young, graduate student Loretta Norton and their colleagues at the London Health Sciences Centre imaged Dr. Possmayer's brain and found normal activity in the circuitry associated with daydreaming. Of the 13 comatose patients in the study, only one other person showed a similar pattern of activity. They were the only two to regain consciousness. The others didn't survive.
Today, after quadruple-bypass surgery, 71-year-old Dr. Possmayer is back playing tennis. He credits a tennis-playing doctor and her sister for helping to preserve his brain function. They administered cardiopulmonary resuscitation, or CPR, while they waited for the ambulance at the club.
It is interesting, he says, to learn about the specific brain circuitry that was humming when he was in a coma. The default mode network, as it is known, is associated with daydreaming, but some scientists suspect it also may act as an operating system for the resting brain.
"The currents were still running," Dr. Possmayer said. "It is probably not an on-off thing. These things never are."
Dr. Young and Ms. Norton say they are thrilled at the prospect of collaborating with Dr. Owen. The research could also lead to new ways to identify people most likely to emerge from comas, Dr. Young says. They could start rehabilitation early, which might lead to better outcomes.
He is also looking forward to answering important questions about the cognitive abilities of patients who appear to be in a vegetative state but can communicate with the help of a brain imager.
Dr. Owen, he says, has gotten further into the heads of these patients than anyone and has shown they can process language and activate motor areas of the brain.
"They can respond to commands. But are they thinking thoughts in there?" Dr. Young asked.
Adam Hampshire, a research associate of Dr. Owen who has already made the move to Western, is working on a test to see if they can reason.
In Cambridge, meanwhile, Dr. Owen is packing up his lab and, at a time when British scientists are being hit with funding cuts, is looking forward to the $10-million over seven years he will receive as a Canada Excellence Research Chair. His departure is being lamented in Britain as part of a brain drain, but he and his wife are dreaming of a Canadian Christmas.
"We are hoping for snow," he said.