title: Post mTBI fatigue is associated with abnormal brain functional connectivity.
abstract: This study set out to investigate the behavioral correlates of changes in resting-state functional connectivity before and after performing a 20 minute continuous psychomotor vigilance task (PVT) for patients with chronic post-concussion syndrome. Ten patients in chronic phase after mild traumatic brain injury (mTBI) with persisting symptoms of fatigue and ten matched healthy controls participated in the study. We assessed the participants' fatigue levels and conducted resting-state fMRI before and after a sustained PVT. We evaluated the changes in brain functional connectivity indices in relation to the subject's fatigue behavior using a quantitative data-driven analysis approach. We found that the PVT invoked significant mental fatigue and specific functional connectivity changes in mTBI patients. Furthermore, we found a significant linear correlation between self-reported fatigue and functional connectivity in the thalamus and middle frontal cortex. Our findings indicate that resting-state fMRI measurements may be a useful indicator of performance potential and a marker of fatigue level in the neural attentional system.
authors.affiliation: Department of Diagnostic Medical Physics, Karolinska University Hospital Huddinge, Stockholm, Sweden.|Department of Clinical Science, Intervention and Technology, Division of Medical Imaging and Technology, Karolinska Institute, Stockholm, Sweden.
authors.forename: Love Engström
authors.initials: LE
authors.lastname: Nordin
authors.affiliation: Department of Clinical Sciences, Danderyd Hospital, KIDS, Karolinska Institute, Solnavägen 1, 171 77 Solna, Sweden.|Centre for Clinical Research, Sörmland, Uppsala University, Uppsala, Sweden.
authors.forename: Marika Christina
authors.initials: MC
authors.lastname: Möller
authors.affiliation: Department of Clinical Sciences, Danderyd Hospital, KIDS, Karolinska Institute, Solnavägen 1, 171 77 Solna, Sweden.|Neurological Rehabilitation Clinic, Stora Sköndal Foundation, Stockholm, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Julin
authors.affiliation: Department of Clinical Sciences, Danderyd Hospital, KIDS, Karolinska Institute, Solnavägen 1, 171 77 Solna, Sweden.
authors.forename: Aniko
authors.initials: A
authors.lastname: Bartfai
authors.affiliation: Department of Clinical Science, Intervention and Technology, Division of Medical Imaging and Technology, Karolinska Institute, Stockholm, Sweden.|Department of Radiology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Farouk
authors.initials: F
authors.lastname: Hashim
authors.affiliation: Department of Diagnostic Medical Physics, Karolinska University Hospital Huddinge, Stockholm, Sweden.|Department of Clinical Science, Intervention and Technology, Division of Medical Imaging and Technology, Karolinska Institute, Stockholm, Sweden.
authors.forename: Tie-Qiang
authors.initials: TQ
authors.lastname: Li
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D016022:Case-Control Studies; D000070627:Chronic Traumatic Encephalopathy / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology*; D005221:Fatigue / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance; D055815:Young Adult