A UK/Belgian team have studied functional magnetic resonance (FMRI) images from a patient who’s been in a coma for five months. Interestingly, in this particular patient, they were able to observe thoughts in response to commands and even were able to see the patient imagining playing tennis.
A team in Cambridge have discovered that a patient in a vegetative state can communicate through her thoughts. Researchers at the Medical Research Council’s Cognition and Brain Sciences Unit and in Academic Neurosurgery in Cambridge, in collaboration with colleagues in Liege, have for the first time discovered a way to show preserved conscious awareness in a patient who has been diagnosed as vegetative. The research is published today in Science.
A year ago, the woman, who is 23, sustained a severe traumatic brain injury in a road traffic accident. She is physically unresponsive and fulfils all the criteria for a diagnosis of vegetative state according to international guidelines.
Using a functional magnetic resonance imaging (fMRI) scanner at the Wolfson Brain Imaging Centre, Cambridge, her brain activity was mapped while the patient was asked to imagine playing tennis or moving around her home. The scientists found she was able to do this, activating different areas of her brain in the same way as healthy volunteers.
“These are startling results. They confirm that, despite the diagnosis of vegetative state, this patient retained the ability to understand spoken commands and to respond to them through her brain activity, rather than through speech or 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,” said Dr Adrian Owen who led the research.
The scientists first used fMRI to measure the patient’s neural responses during the presentation of spoken sentences (e.g. “there was milk and sugar in his coffee”). These tests showed she recognised speech. Furthermore, more complex sentences that contained ambiguous words (e.g. “the creak came from a beam in the ceiling”) produced an additional significant response. This indicated that the brain understood the meaning of the sentences.
Although, an appropriate neural response to the meaning of spoken sentences suggests someone is consciously aware, it does not confirm that they are. So to work out whether or not the patient was able to understand and respond, she was asked to imagine certain activities like playing tennis or walking around her home. The brain activity of the patient was indistinguishable from that of healthy volunteers.