Patient in a coma plays tennis.

摘要

Researchers have shown that a patient diagnosed as being in a vegetative state does have conscious thought. Using functional MRI (fMRI), Adrian Owen (Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK) and colleagues assessed the patient's neural responses to various spoken sentences and requests to perform imagery tasks and these were compared with controls' responses (Science 2006; 313:1402).Patients can enter a vegetative state after a head injury or after being in a coma. They have no awareness of self or environment but are defined as being awake-patients will typically have intact brainstem centres awd reflexes.In July, 2005, a woman, aged 23 years, sustained a severe traumatic brain injury in a road traffic accident. At 5 months the patient remained unresponsive but had normal sleep-wake patterns and was diagnosed as being in a vegetative state. Owen's group presented spoken sentences to the patient and assessed her fMRI; speech-specific activity was reported bilaterally in the middle and superior temporal gyri, these results were identical to the controls' responses. In a second experiment, the researchers played prerecorded spoken instructions ("imagine playing tennis", "imagine visiting the rooms in your home", "now just relax") followed by periods of rest. When asked to imagine playing tennis, significant activity in the supplementary motor area was reported on fMRI. When asked to imagine walking through her house, significant activity was reported in the patient's parahippocampal gyrus, posterior parietal cortex, and lateral premotor cortex. All neural responses to these tasks matched those of the controls.