Author Interviews, Brain Injury, JAMA / 21.10.2015
Study Identifies Pathway For Retained Awareness In Vegetative State
MedicalResearch.com Interview with:
Dr Davinia Fernández-Espejo PhD
School of Psychology
University of Birmingham
Birmingham
Medical Research: What is the background for this study? What are the main findings?
Dr. Fernández-Espejo: We have previously shown that a number of patients who appear to be in a vegetative state are actually aware of themselves and their surroundings, and simply unable to show it with their external behavior. In a prior study we demonstrated that a patient who had been repeatedly diagnosed as vegetative state for 12 years was not only fully aware but able to create memories. Notably, this patient was capable to modulate their brain activity in a functional magnetic resonance imaging (fMRI) scanner to answer questions about their condition and preferences for care. In the present study we identified the reason for the dissociation between these patients’ retained awareness and their inability to respond with intentional movement.
First, we used fMRI to demonstrate that a functional connection between the thalamus and the motor cortex is essential for a successful execution of voluntary movements.
Second, we used diffusion tensor tractography, a technique that allows reconstructing and assessing white matter pathways in the brain, to identify damage to such connection (i.e. thalamus and motor cortex) in a paradigmatic patient who produced repeated evidence of covert awareness across multiple examinations, despite clinically appearing as being in a vegetative state.
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