Objective: To investigate whether functional magnetic resonance imaging (fMRI) can be used to detect fatigue after traumatic brain injury (TBI).
Setting: Neurorehabilitation clinic.
Participants: Patients with TBI (n = 57) and self-experienced fatigue more than 1 year postinjury, and age- and gender-matched healthy controls (n = 27).
Main measures: Self-assessment scales of fatigue, a neuropsychological test battery, and fMRI scanning during performance of a fatiguing 27-minute attention task.
Results: During testing within the fMRI scanner, patients showed a higher increase in self-reported fatigue than controls from before to after completing the task (P < .001). The patients also showed lower activity in several regions, including bilateral caudate, thalamus, and anterior insula (all P < .05). Furthermore, the patients failed to display decreased activation over time in regions of interest: the bilateral caudate and anterior thalamus (all P < .01). Left caudate activity correctly identified 91% of patients and 81% of controls, resulting in a positive predictive value of 91%.
Conclusion: The results suggest that chronic fatigue after TBI is associated with altered striato-thalamic-cortical functioning. It would be of interest to study whether fMRI can be used to support the diagnosis of chronic fatigue in future studies.