PATIENTS who are in a vegetative state may be able to hear and understand much more than hitherto believed.

Experiments conducted in Cambridge could change the way in which such patients are treated: the results suggest that even those who seem to be comatose can hear, understand and respond.

Decisions to switch off life-support systems, always a controversial area in which the courts are often involved, could become even more fraught.

The experiments, published in Science, were carried out on a 23-year-old woman who suffered serious head injuries in a traffic accident in July last year. Five months after the accident the woman remained unresponsive, although she continued normal cycles of sleeping and waking. Doctors diagnosed her condition as a vegetative state, one in which patients who emerge from a coma appear to be awake but show no sign of awareness.

Scientists at the Medical Research Council’s Cognition and Brain Sciences Unit, with colleagues from Liège, Belgium, decided to use modern brain-scanning methods — a functional MRI scanner — to discover whether her brain retained any of its functions.

The woman was asked to imagine playing tennis, or walking round her home, while her brain was being scanned. When the requests were made, distinct parts of her brain were activated.

These were exactly the same areas of brain that were activated in healthy volunteers asked to imagine the same things.

“These are startling results,” said Adrian Owen, who led the research. “They confirm that, despite the diagnosis of a vegetative state, this patient retained the ability to understand spoken commands and to respond to them through her brain activity, rather than through speech and movement.

“Her decision to work with us by imagining particular tasks when asked represents a clear act of intent which confirmed beyond any doubt that she was consciously aware of herself and her surroundings.”

Dr Owen added: “This technique may allow us to identify which patients have some level of awareness. But it is important to emphasise that if we don’t see responses in a patient it does not necessarily mean they are not aware.

“Future work will investigate whether the technique can be used more widely in these patients and whether this discovery could lead to a way of communicating with some patients who may be aware, but unable to move or speak.”

Other scientists said that the study raised interesting scientific, medical and ethical issues.

Narender Ramnani, a neuroscientist from Royal Holloway, University of London, said that the results added weight to the view that the patient, and others like her, “might be quite capable of decision-making and have a rich and complex internal life”. But he cautioned that the findings were based on a single case and more research was needed to investigate this possibility more robustly.

Paul Matthews, Professor of Clinical Neurosciences at the University of Oxford, was more sceptical. “When patients are in a vegative state they can react to stimuli but not in a truly meaningful way,” he said. “In my opinion the study alone does not provide sufficient evidence that there is conscious interaction with the environment.”

He disagreed with the team that the woman had made a decision to co-operate. The observations had not established that, or that she had self-awareness, he said.

“Response to stimuli, even complex linguistic stimuli, does not provide evidence of a decision to respond. Withdrawal from an unexpected painful pin prick does not represent a decision to respond.”

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