New hope for head injury patients
A method of communicating with brain damaged patients who appear to be in a vegetative state has been discovered by scientists in the UK and Belgium.
Writing in The Lancet medical journal they describe how they measured electrical activity in the brain to detect consciousness.
The technique, known as EEG, is painless and involves attaching electrodes to the head.
Doctors hope it can be used as a diagnostic tool in homes and hospitals.
The trial involved 16 patients at Addenbrooke's Hospital in Cambridge and the University Hospital of Liege in Belgium.
All had been diagnosed as being in a vegetative state - a condition where a person is awake, but has no sense of awareness of themselves or their surroundings.
The patients were asked to imagine wiggling their toes or squeezing their right hand. The brain activity of three of the 16 patients showed they were repeatedly able to follow commands.
The report author, Professor Adrian Owen, from the Centre for Brain and Mind, University of Western Ontario, Canada said: "Many areas of the brain that activate when you perform a movement also activate when you imagine doing it.
"We know these three patients were conscious as they were able to respond repeatedly to the instructions we had given them. One of the patients was able to do it more than 100 times."
Professor Owen's team at the MRC Cognition and Brain Sciences Unit in Cambridge previously showed that it was possible to communicate with some vegetative patients using functional magnetic resonance imaging (fMRI).
But many brain injured patients cannot be assessed in these scanners because they have metal plates or pins, or they are unable to remain still.
The EEG device is comparatively cheap and portable. Professor Owen said: "This is exciting because it means we can get out into the community, take it to patients in nursing and care homes, and assess many more patients at the bedside to see if we can detect covert awareness."
Helen Gill-Thwaites, a consultant in the diagnosis of low awareness states at the Royal Hospital for Neuro-disability (RHN) in Putney said: "For a small proportion of patients EEG could be a very useful tool in the diagnostic process.
"It would however be a useful addition and not a replacement, to current methods of assessing severely brain-injured patients.
"Sadly, in my work outside of the RHN I meet many patients who have never had a proper assessment and have been wrongly diagnosed as being in a vegetative state."
Paul Matthews, Professor of Clinical Neurosciences, Department of Medicine, Imperial College, London said: "The approach suggests a simple, practical way in which some of these patients might be helped to communicate.
"This innovative work has taken fundamental brain science right to the bedside. Efforts to further evaluate this and related approach in the clinic should be prioritised."