'Locked in' patient talks with only his thoughts
Ground-breaking study offers brain injury hope
Published 04/02/2010 | 05:00
A MAN who was presumed to be in a vegetative state for five years has answered questions using his thoughts alone in a ground-breaking experiment that promises to allow some patients who are 'locked in' by brain injuries to communicate.
The 29-year-old Belgian was able to reply to simple "yes"/"no" questions such as "Is your father's name Alexander?" by changing his brain activity. Scientists then read his answers by studying functional magnetic resonance imaging (fMRI) scans.
He had previously failed to show any signs of consciousness after suffering a severe brain injury in a road accident. A vegetative state (VS), in which patients wake from a coma but appear to have no awareness, had been diagnosed.
The remarkable results, from British and Belgian researchers, suggest that at least some VS patients are able not only to hear and understand people, but also to respond mentally.
"It's very possibly the case that we will get into a situation within 10 years where patients incapable of any response are able to communicate using their brain alone," said Adrian Owen, of the Medical Research Council (MRC) Cognition and Brain Sciences Unit in Cambridge, a leader of the research.
The advance, however, raises difficult ethical questions, such as whether patients could use the technology to express a wish to die. While they may be able to answer "yes"/"no" questions, their brain damage may mean they lack the capacity to give informed consent to life-or-death decisions.
"An obvious question you might ask is whether you want to be kept alive, but there are ethical and legal hurdles that need to be crossed to determine whether a patient has the cognitive wherewithal to make decisions like this for themselves," Dr Owen said.
He said that the findings, which are published in 'The New England Journal of Medicine', had been a comfort to the patient's relatives. "One of the most difficult things in this situation is not knowing whether you're getting through, whether your loved one can understand you," he said.
He emphasised, however, that not every patient in a vegetative state is aware. Of 23 who were scanned with fMRI so far, only four have shown to retain clear signs of consciousness.
The research, which was also led by Steven Laureys of the MRC unit, builds on a study published in 2006 in which the team found that a 23-year-old woman who seemed to be in a vegetative state was conscious.
Scientists scanned her brain while she was asked to imagine playing tennis or moving from room to room in her home, and saw activity in parts of the brain responsible for motor control and navigation respectively.
They have since scanned a further 22 patients, three more of whom showed similar patterns of brain activity. They then devised a way of using this to try to establish communication, by scanning the brains of healthy people.
These volunteers were asked to imagine playing tennis if the answer to a question was "yes", and to imagine moving through their house to say no. Answers were 100pc accurate.
The technique was then used to attempt to communicate with the Belgian man. He was asked six questions. He answered the first five successfully, while no answer was obtained to the sixth. This could have been because the patient fell asleep or lost consciousness.
The team plans to repeat the experiment. The next goal will be to refine the technique, to determine whether similar results can be achieved with simpler scanning technology such as electroencephalograms (EEGs).
This could allow patients to communicate routinely, rather than only when inside an fMRI scanner -- an expensive and difficult procedure. (© The Times, London)