Brain scans show unconscious woman played tennis in her head

Sep 11 2006

Neuroscientists at Britain's Cambridge University say functional magnetic resonance imaging or fMRI brain scans appear to show that a woman in a vegetative state seemed to play tennis in her head despite the fact that she had been unconscious for five months after a motor vehicle accident.

The case has emphasised how frustrating it can be to try to establish what is going on in the brain of someone who is immobile and outwardly unresponsive.

The British and Belgian researchers say the fMRI brain scans showed the 23-year-old woman showed evidence of awareness of herself and her environment in response to verbal commands.

She appeared to respond to commands to imagine playing a game of tennis and walking through her home.

The scans were compared with others taken when the patient was presented with acoustically-matched noise sequences.

The woman had been unresponsive since emerging from a coma after a traffic accident and met all the criteria for a persistent vegetative state.

When she was presented with spoken sentences she had increased activity in speech comprehension centers in the brain, which were as seen on the scans.

Adrian M. Owen, Ph.D., and colleagues at Cambridge University and the University of Liege, Belgium, say their study showed the woman was conscious, although she had lain still and silent for five months after the accident.

Her decision to cooperate with the authors by imagining particular tasks when asked to do so, they say represents a clear act of intention, which 'confirmed beyond any doubt that she was consciously aware of herself and her surroundings'.

Experts however are in complete agreement that the case does not mean that many people in apparently vegetative states may in fact be conscious and Owen himself says it is more likely that the woman may in fact have been on the road to recovery and moving to a less severe state known as a minimally unconscious state.

People have been known to survive in such states for years; American Terry Wallace recovered from minimal consciousness in 2003, 19 years after a car accident and experts believe such scans may offer a way to predict which patients are most likely to recover.

Dr. Nicholas Schiff, a neuroscientist at Weill Cornell Medical College in New York, who has been using fMRI in patients in a similar state says he has never seen anything like this, but says there are patients that they will try this on.

Schiff has one of the two labs in the world which perform such tests the other is run by Dr. Steven Laureys at the University of Liege, who worked with Owen to assess the British patient.

Apparently the work is difficult as patients in such states can move, making MRI scans blurred and useless, and it can be difficult to determine when they are asleep and thus unlikely to respond to anything.

Experts say the study shows it is possible to make a mistake in diagnosing a patient as unconscious but it is unclear how often such a discrepancy between the physical exam findings and fMRI findings would be seen, but the case is important because it illustrates the limitations of the physical exam to assess awareness.

Neurologists agree the British case has little relevance to the debate over Terri Schiavo, a Florida woman who spent 15 years in a persistent vegetative state who was the centre of a medical and political storm last year; she was allowed to die in March 2005 after a long court battle.

Some of Schiavo's relatives were convinced she could recover, but Schiavo had been in a vegetative state for much longer than the British woman, resulting in the severe deterioration of her brain.

Experts also point out that the British woman had relatively little brain damage, and said traumatic brain injury often healed better than injury caused by stroke or heart attack such as Schiavo had suffered.

In order to avoid a flare-up of the Schiavo debacle, the editors of Science, have said in a statement that the paper is a single case report, and therefore should not be used to generalize about all other patients in a vegetative state, particularly since each case may involve a different type of injury.

According to the National Institute for Neurological Disorders and Stroke (NINDS) people who are in a persistent vegetative state have lost their cognitive abilities and awareness of their surroundings, but retain non-cognitive function and normal sleep patterns.

Although they may move, grunt, cry, or laugh, the diagnosis hinges on an absence of reproducible evidence that such movements or behaviors are purposeful responses to external stimuli.

Dr. Owen and colleagues say the findings suggest that it might be possible for patients who have been diagnosed as being in minimally conscious states or locked in due to degenerative neuromuscular disorders to "use their residual cognitive capabilities to communicate their thoughts to those around them by modulating their own neural activity.