Communicating with patients in a vegetative state

It's hard to imagine anything worse than being trapped in a useless body. Fully aware of what's happening around you, but unable to move or communicate.

That was the situation for the French journalist Jean-Dominique Bauby after a severe stroke left him physically paralysed, or "locked-in". The only function Bauby retained was the ability to blink his left eye - a skill he painstakingly exploited to dictate The Diving Bell and the Butterfly, letter by letter.

It was assumed the patients involved in a new study on Persistent Vegetative States, and published today in the New England Journal of Medicine, didn't even retain that limited level of physical ability or any mental awareness. Unlike locked-in syndrome, patients in a vegetative state appear to be awake, but are unresponsive and there's no sign of intellectual activity.

The team, lead by Dr Adrian Owen at Cambridge University, used a functional MRI scanner to test the brain activity of 23 patients thought to be in a vegetative state.

To their astonishment they were able to detect awareness in four of the subjects, and one man (a 29 year old Belgian who had sustained severe brain injuries in a car accident five years earlier) appeared to understand what was going on in the experiment, and was able to answer a series of questions about is life by directing his thoughts to signal yes or no.

Functional Magnetic Resonance Imaging picks up on minute changes in the activity of protons in the brain.

Thinking about different things produces different patterns of neural activity that can be "read" by the scanner.

In this experiment researchers asked each patient to imagine playing a shot in tennis for yes, and walking from one room to another at their home when they wanted to indicate no.

The discovery has profound implications - not least for the diagnosis of PVS.

"Not only do these scans tell us that the patient is not in a vegetative state" Dr Owen says, "but more importantly, for the first time in 5 years it has provided him with a way of communicating his thoughts to the outside world."

The discovery that some patients previously thought to be in a vegetative state are actually aware of their surroundings might be unsettling for friends and relatives, but the researchers hope it can be exploited to address important clinical questions.

It might be possible for patients to indicate if they are in pain, for instance, or to be consulted over decisions about their treatment.

"It's early days," says Dr Steven Laureys, a co-author from the University of Liege, "but in the future we hope to develop this technique to allow some patients to express their feelings and thoughts, and to increase their quality of life".