And they said a woman who made headlines last year by playing a game of tennis in her mind has recovered somewhat from her vegetative state — suggesting the theory may be correct.
Adrian Owen and colleagues at Britain\’s Cambridge University started a debate when they reported in September on a woman who had been in a vegetative state for six months since a car accident.
A vegetative state is far more serious than a coma — patients have reflexes, but there is no indication they are in any way conscious. Patients in a persistent vegetative state, lasting for more than two years, have virtually no hope of recovery.
But because reflexes can be misleading, doctors often struggle to categorize and diagnose such patients.
Using functional magnetic resonance imaging to look at the brain\’s real-time activity, Owen\’s team asked the woman to imagine she was playing tennis or walking through her home. To their surprise, her brain lit up, showing activity in all the sites that be would expected.
Her scans showed brain activity nearly identical to that of healthy people asked to perform the same task, Owen and colleagues report in the Archives of Neurology.
Owen said his team has tried the scan on 10 other patients, but got a response only from one, a man in his 30s in a vegetative state after a severe beating. "We put him in the scanner and we had exactly the same responses."
Owen said it is important not to over-interpret the findings, although it may be possible to predict who is likely to recover. "We don\’t want to raise false hopes or make people think all minimally conscious patients are aware," he said.
And the first patient is improving.
"About six months after we scanned her, she started to show the earliest signs of improvement," he said in a telephone interview. "She is now in a minimally conscious state. She is able to produce responses occasionally but not consistently."
So far, Owen said, it appears that people are more likely to recover from traumatic brain injuries than losing consciousness because they lacked oxygen — such as Terri Schiavo, a Florida woman who spent 15 years in a persistent vegetative state and was allowed to die in March 2005 after a long legal battle.
The bad news is that no one yet knows how to help such patients recover, although researchers reported this month on a patient who improved after deep-brain stimulation.
"To be perfectly honest, there is as yet no treatment or intervention that has been empirically tested and shown to be beneficial in this patient group," Owen said.