An fMRI study of executive functioning after severe diffuse TBI.
PRIMARY OBJECTIVE: Preliminary study of whether severe diffuse traumatic brain injury (TBI) increases extent of frontal tissue recruited by cognitive control tasks. RESEARCH DESIGN: Functional magnetic resonance imaging (fMRI) on N-back working memory (WM)and arrows inhibition tasks in a 46 year old man who had severe diffuse TBI 1 year earlier, a 44 year old man (inhibition task) and three women (working memory task), age 20-26 years. Images were acquired by 1.5 T magnet with BOLD method and PRESTO pulse sequence and analysed using SPM. MAIN OUTCOMES AND RESULTS: Frontal activation increased under 2-back relative to 1-back condition of working memory in all participants with more extensive activation in the TBI patient relative to controls. Frontal activation increased with inhibition on the arrows task, but was greater in the TBI patient. CONCLUSION: Severe diffuse TBI results in recruitment of additional neural resources for cognitive control.