VOA常速英语:Brain Scans Find Consciousness in Some Vegetative Patients

It sounds almost like science fiction: could some patients believed to be in vegetative or minimally conscious states really be conscious all along? And perhaps with new technology, be capable of communicating? Such conditions are caused mainly by stroke, traumatic brain injury, and heart attack.? A recent study could give hope to some of these patients, while raising ethical and legal questions about a patient's quality of life.

For more than two decades, Rom Houben was misdiagnosed as being in a vegetative state, after a car accident. Then doctors discovered through a brain scan that he was conscious and possessed normal brain function.

At first it seemed the 46-year-old Belgian could communicate with tiny movements of his fingers as an aide guided his hand on a keyboard. But experts later disproved that. Doctors say Houben has some awareness of self and his surroundings, but cannot communicate.

Now research suggests that patients once misdiagnosed as unresponsive, like Houben might someday, with the right tools, be able to communicate directly from the brain.

Fifty-four apparently unresponsive patients were placed in MRIs (magnetic resonance imaging scanners), and told to visualize different scenes: playing football or walking through the house. In five of the 54 patients, those scenes activated and lit up separate parts of the brain.

One patient went on to correctly answer five out of six yes-or-no questions about his own life - by visualizing football to communicate 'Yes,' or walking through the house for 'No.' Professor Steven Laureys of the University of Liege in Belgium is one of the researchers.

"It opens a new era where we need to prepare for what we are going to do with this technology," he said. "We can ask big questions here. This will have major medical, ethical and legal impact."

Another leading researcher, Dr. Nicholas Schiff of New York's Presbyterian Cornell Weill Medical Center, says the study will lead to more accurate diagnoses, identifying unresponsive patients who have the potential to communicate.

"Whether they then could harness some sort of communication device and establish systematic communications, whether they could then initiate communication - these are all these unknowns," he said. "But we've found when patients can do that, it makes a very big difference for them, and at the moment I think these are going to be very big health-care delivery issues."

Schiff says the research doesn't apply to people who are brain-dead, whose bodies are kept alive by machines, or for those in comas. But the study could offer hope for seemingly unresponsive patients who might one day be able to communicate their thoughts.