Hospital patients left in the twilight zone between consciousness and unconsciousness known as "vegetative state" as a result of a severe illness or traumatic injury may be able to communicate with their carers for the first time thanks to a simple bedside device enabling doctors to read their minds.
In 2010 scientists from the University of Cambridge used an advanced brain scanner to detect signs of consciousness in patients thought to lack all awareness. They have now reproduced the results using a portable electroencephalograph (EEG) machine. Future refinements could allow two-way communication and open the technique to many patients who are prisoners within their own bodies. Advanced brain scanners are scarce, expensive (over £1m) and unwieldy, but EEG machines are portable, cheap (£20,00 to £30,000) and ubiquitous.
Three patients out of 16 thought to be in a vegetative state were able to respond to commands to imagine moving their right hand or wiggling their toes. The researchers could see from their brain waves that they were responding, even though no movement occurred. The trial was led by Adrian Owen, a neuroscientist at Addenbrooke's Hospital, Cambridge, who has since moved with several of his research team to the University of Western Ontario, Canada. The results are published in The Lancet.
Several thousand people are in a vegetative state in hospitals at any one time in Britain, cut off from contact with their family and carers. The research aims to establish a means of regular communication to find out what they are thinking and feeling so that their needs can be met. It might be possible to do this by placing electrodes on their head and connecting them to a computer.
"This method could reach all vegetative patients and fundamentally change their bedside assessment," the authors say.
Experts hailed the advance but warned it raised a host of ethical and practical questions. Julian Savulescu, director of the Oxford Centre for Neuroethics, said being minimally conscious could be worse than being permanently unconscious.
"The important ethical question is not: are they conscious? It is: in what way are they conscious? Are these patients suffering? How bad is their life? Do they want to continue in that state? If they could express a desire, should it be respected? For some of these patients, consciousness could be the experience of a living hell. The big question – how such patients should be treated – remains as open as ever."
Paul Matthews, professor of clinical neurosciences at Imperial College, London, said use of the technique as a means of communication had not been established. "The reproducibility of the measures was not explored. Do the patients displaying awareness always respond in this way? It is likely that the sensitivity of the method is limited."
Register for free to continue reading
Registration is a free and easy way to support our truly independent journalism
By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists
Already have an account? sign in
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies