fMRI study of problem-solving after severe traumatic brain injury

Objective: To assess the cerebral correlates of the dysexecutive syndrome after diffuse severe traumatic brain injury (TBI). Methods: Ten patients with sub-acute/chronic severe TBI without detectable focal cortical contusion and 11 matched healthy subjects were included in a parametric fMRI study using a planning task, the Tower of London. Results: Brain activation in the left Dorsolateral Pre-frontal Cortex (DLPFC) and the Anterior Cingulate Cortex (ACC) was closely related to performance. Patients with TBI who performed the task efficiently showed, like healthy controls who obtained a similar pattern of performance, a large activation in the left DLPFC and a small activation in the ACC. In contrast, poor performance was associated with a reduced activation in these both regions. Conclusion: Problem-solving deficits after severe diffuse TBI could be related to an impaired activation of the DLPFC and of the ACC.