Brain activity detected in 'vegetative' patients

Many of the patients were labeled with the same diagnosis: "vegetative state." Their head injuries, teams of specialists had concluded, condemned them to a grim condition: alive yet devoid of awareness of the world around them.

But an international team of scientists decided to try to peek inside their minds to determine whether they were conscious.

Technicians gave them careful instructions: Imagine you are playing tennis. Imagine you are exploring your home, room by room. For most, the scanner showed nothing.

But, for one, then another, and another, and two more, the scans flashed alive exactly like any healthy conscious person's would. These patients, the images clearly showed, were living silently in their bodies, their minds apparently active. One man could answer detailed yes-or-no questions about his life before his trauma.

"It was incredible," said Adrian Owen, a University of Cambridge neuroscientist who led the research described in a paper published online Wednesday in The New England Journal of Medicine. "These are patients who are totally unable to perform functions with their bodies — even blink an eye or move an eyebrow — but yet are entirely conscious. It's quite distressing, really, to realize this."

Providing insights

While stressing that much more research is needed to confirm findings, Owen and other experts said the findings could provide insights into human consciousness and lead to better diagnose and treat tens of thousands of brain-injury patients. The technology also offers the possibility of being able to communicate with some patients and ask, at the very least, whether they are in pain and need relief.

"This should change the way we think about these patients," said Nicholas Schiff, an associate professor of neurology and neuroscience at the Weill Cornell Medical College in New York. "I think it's going to have very broad implications."

The research inevitably raised 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 that led to congressional intervention. Schiavo's brother, Bobby Schindler, said the new study highlights the limits of medicine to provide an accurate diagnosis.

"They are completely unreliable," Schindler said.

Positive signals

However, researchers noted the positive signals appeared only in people with traumatic brain injury, not in patients whose brains had been deprived of oxygen, as can happen when the heart stops. Schiavo, whose feeding tube was removed and was allowed to die in 2005, suffered oxygen deprivation.

Owen, Schiff and other experts also stressed the research does not indicate that many patients in vegetative states are necessarily aware or have any hope of recovery. "In some cases, the damage to the brain is so severe that it is simply inconceivable they could produce any responses," Owen said.

Up to 20,000 Americans have been diagnosed as being in a vegetative state, meaning they are alive and awake, but without any sense of awareness, while 100,000 to 300,000 are in a related condition known as a minimally conscious state, in which they exhibit impaired or intermittent awareness.

A growing body of evidence in recent years has indicated a significant proportion of such patients' conditions may be misdiagnosed and they have more awareness than had been thought.

In 2006, Owen and his colleagues described the case of a woman diagnosed as being in vegetative state whose brain responded identically to a normal brain when placed inside a device known as a functional Magnetic Resonance Imaging (fMRI) scanner and asked to imagine herself playing tennis or exploring her home. The case electrified neuroscientists. But it remained unclear whether her case was a fluke or representative of a population of patients languishing with misdiagnoses.

Flood of requests

Flooded with requests from families to assess their loved ones, Owen and colleagues at the University of Liège in Belgium started testing more patients. In the new report, researchers describe the results from the first 54, including 23 who had a vegetative state diagnosed and 31 whose diagnosis was minimal consciousness.

Five, including the first woman, were able to repeatedly fire their brains in precisely the same way as hundreds of normal volunteers who were put in the fMRIs and asked to imagine themselves hitting a tennis ball and wandering through their homes. Four of the five had been diagnosed as being in vegetative state, and one was thought to be only minimally conscious. Three showed signs of awareness during intensive standard bedside tests, but two did not.

Researchers decided to see if they could use the approach to communicate with a patient. They told a 29-year-old Belgian, injured in a traffic accident, to think about tennis if he wanted his answers to be "yes" and imagine touring his home for "no." They then asked him a series of questions about his life, such as whether his father's name was Thomas and whether he had brothers or sisters. He answered every question correctly.

"He could produce no communication with his body," Owen said. "But he could systematically and repeatedly change his brain activity to indicate 'yes' or 'no' with 100 percent accuracy."

Owen cautioned the approach could only identify patients who are conscious, and could not determine if a lack of response was because they couldn't hear the questions, were asleep or the result of some other factor.

Information from The Associated Press is included in this report.