(RxWiki News) As many as 19 percent of brain-damaged patients in a vegetative state may be aware of their surroundings and capable of communicating, research has revealed.
That number is larger than previously suspected. A new inexpensive test can help pinpoint which patients have maintained that awareness after brain damage.
"There may be hope for communicating with patients in vegetative states."
Adrian Owen, a Canada Excellence Research Chair in Cognitive Neuroscience and Imaging at the University of Western Ontario's Centre for Brain and Mind, and Damian Cruse, the lead writer of the new study, also from the University of Western Ontario, said the method for assessing consciousness among patients who appear to be in a vegetative state, but may be able to respond, is both practical and cost-effective.
Cruse said the new method for detecting awareness among patients in a vegetative state using electroencephalography (EEG) is relatively cheap, portable and widely available.
Researchers utilized an EEG paradigm with motor imagery to detect command following, an indicator of awareness, in 16 patients who met internationally agreed upon criteria for a diagnosis of vegetative state. The test was repeated in 12 healthy patients.
Investigators found activity in the front part of the brain in three of the patients believed to be in a vegetative state -- the same part of the brain that showed activity among the healthy participants.
“It’s astonishing,” Owen said. “In some of these cases, patients who seemed to be entirely unresponsive to the outside world, were able to signal that they were, in fact, conscious by changing their patterns of brain activity – sometimes hundreds of times ”
In some cases doctors may be able to communicate with patients in a vegetative state through functional magnetic resonance imaging (fMRI), though at this time it is expensive and not as widely available.
The findings were published in The Lancet.