In 'vegetative state' patients, brain scanners show some alert minds
Thursday, February 4, 2010
Many of the patients were labeled with the same grim diagnosis: "vegetative state." Their head injuries, teams of specialists had concluded, condemned them to a netherworld -- alive yet utterly devoid of any awareness of the world around them.
But an international team of scientists decided to try a bold experiment using the latest technology to peek inside the minds of 54 patients to see whether, in fact, they were conscious.
One by one, the men and women were placed inside advanced brain scanners as 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, shockingly, for one, then another, and another, and yet two more, the scans flashed exactly like any healthy conscious person's would. These patients, the images clearly indicated, were living silently in their bodies, their minds apparently active. One man could even flawlessly answer detailed yes-or-no questions about his life before his trauma by activating different parts of his brain.
"It was incredible," said Adrian M. Owen, a neuroscientist at the Medical Research Council who led the groundbreaking research described in a paper published online Wednesday by 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."
Although Owen and other experts stressed that much more research is needed to confirm findings and refine the technology, they said the results could provide profound insight into human consciousness -- one of the most daunting scientific mysteries -- and lead to ways to better diagnose brain injuries and treat tens of thousands of patients. The technology also offers the tantalizing possibility of being able to finally 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 D. Schiff, an associate professor of neurology and neuroscience at Weill Cornell Medical College in New York City. "I think it's going to have very broad implications."
The research inevitably raised questions about patients such as Terri Schiavo, a 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 in 2005. Schiavo's brother, Bobby Schindler, said the new study highlights the limits of medicine to provide an accurate diagnosis.
"I wish this could have been used on my sister to see what could have been done to help her," Schindler said in a telephone interview.
But Owen, Schiff and other experts stressed that the research does not indicate that many patients in vegetative states are necessarily aware or have any hope of recovery. Many, like Schiavo, have suffered much greater danger to their brains for far longer than the patients in the study.
"In some cases, the damage to the brain is so severe that it is simply inconceivable they could produce any responses," Owen said.
As many as 20,000 Americans are in a vegetative state, meaning they are alive and awake but without any apparent sense of awareness, and 100,000 to 300,000 are in a related condition known as a minimally conscious state, in which they exhibit impaired or intermittent awareness. It is unclear what proportion of these patients would be affected by the study's findings.