SCIENTISTS have reached into the shuttered world of a “lost” brain damaged patient and communicated with him via his thoughts.
The 29-year-old Belgian was able to answer “yes” and “no” to questions by conjuring up imaginary scenes while having his brain scanned.
Before the extraordinary experiment the man, who suffered a severe head injury in a road accident in 2003, had shown no sign of being aware of the outside world.
Five years ago he was presumed to have slipped from a coma to a vegetative state, leaving his body functioning but his personality and consciousness wiped out.
The British and Belgian researchers now know that the diagnosis was wrong. The man was able to respond to questions about his life as scientists monitored activity in his brain.
Yesterday they admitted to being “astonished” by the result, which has enormous implications for the care and treatment of vegetative patients.
The man was one of 23 patients diagnosed as being in a vegetative state recruited for a three-year study conducted by Medical Research Council (MRC) scientists in Cambridge and colleagues from the University of Liege in Belgium.
Its aim was to see if brain scans could detect signs of awareness in patients who were thought to be closed off from the world.
Functional magnetic resonance scanning was used to measure activity in “motor” and “spatial” brain regions while the patients imagined specific scenes. The scans use magnetic fields and radio waves to detect surges of blood flow that accompany neural activity.
For the “motor” task, patients were asked to imagine standing still on a tennis court and swinging an arm to return balls from an instructor. To activate the “spatial” region, they had to imagine navigating the streets of a familiar city or walking from room-to- room in their home.
In four cases, the scans were able to detect activity in the appropriate brain region as the patients carried out the scientists’ verbal instructions.
But one Liege patient who had produced reliable responses was singled out for an even more remarkable test. He was asked to use “motor” or “spatial” imagery as “yes” and “no” answers to questions.
The patient responded accurately to five out of six autobiographical questions posed by the scientists.
On one occasion he was asked “is your father’s name Alexander?” and correctly answered “yes” by imagining the tennis scene. When he was asked “is your father’s name Thomas?” he answered “no” by thinking about roaming streets or walking around the house.
However when the sixth question was asked, virtually no activity was seen in either brain region. Scientists believe it is possible the patient had fallen asleep or failed to hear the question.
Dr Adrian Owen, whose team developed the technique at the MRC Cognition and Brain Sciences Unit in Cambridge, said: “Not only did these scans tell us that the patient was not in a vegetative state, but, more importantly, for the first time in five years it provided the patient with a way of communicating his thoughts to the outside world.”
Colleague Dr Steven Laureys, from the University of Liege, said the scans had given the patient his only means of communication since the accident.
He added: “It’s early days, but in the future we hope to develop this technique to allow some patients to express their feelings and thoughts, control their environment and increase their quality of life.”
One way the technique could be used would be to help doctors find out if patients who cannot move or speak are feeling pain.
The study was published today in the New England Journal of Medicine.
Professor Chris Frith, a leading neuropsychologist from the Wellcome Trust Centre for NeuroImaging at University College London, said: “Obviously more technical development is required, but we now have the distinct possibility that, in the future, thanks to Owen and colleagues’ work we will be able to detect cases of coma patients who are conscious and what’s more, we will be able to communicate with them.”
Dr Nicholas Schiff, a neuroscientist at the Weill Cornell Medical College in New York, said: “The most important question left unanswered by these findings is what mechanism accounts for the stunning dissociation of behaviour and integrative brain function.”
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