title: Post-concussive complaints after mild traumatic brain injury associated with altered brain networks during working memory performance.
abstract: The aim was to investigate brain network function during working memory (WM) task performance in patients with uncomplicated mild traumatic brain injury (mTBI) in the sub-acute phase post-injury. We were particularly interested in differences between patients with (PCC-present) and without post-concussive complaints (PCC-absent). Fifty-two patients and twenty healthy controls (HCs) (matched for age, sex, education and handedness) were included. Two patient groups were created based on reported post-concussive complaints at two weeks post-injury: PCC-present (n = 32) and PCC-absent (n = 20). Functional MRI scans were made at approximately four weeks post-injury. Participants performed an n-back task consisting of three conditions (0-, 1- and 2-back) with increasing difficulty. General linear model analysis was performed to investigate activation patterns. Independent component analysis was used to identify brain networks. The frontal executive network (FEN), frontoparietal network (FPN) and default mode network (DMN) were selected for further analyses based on their highest task-relatedness. Task accuracy and reaction times were similar for patients with mTBI and HCs. During high WM load (2-vs.0-back contrast), mTBI patients exhibited lower activation within the medial prefrontal cortex compared to HCs. No differences were found between PCC-present and PCC-absent patients. Regarding network function, PCC-absent patients showed stronger deactivation of the DMN compared to PCC-present patients and HCs, especially during difficult task conditions. Furthermore, functional connectivity between the DMN and FEN was lower in PCC-absent patients compared to PCC-present patients. Interestingly, network function did not differ between PCC-present patients and HCs, suggesting that non-injury related factors may underlie post-concussive complaints after mTBI.
authors.affiliation: Department of Neurology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands. h.j.van.der.horn@umcg.nl.
authors.forename: Harm J
authors.initials: HJ
authors.lastname: van der Horn
authors.affiliation: BCN NeuroImaging Center and Department of Neuroscience, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Edith J
authors.initials: EJ
authors.lastname: Liemburg
authors.affiliation: Department of Neuropsychology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Myrthe E
authors.initials: ME
authors.lastname: Scheenen
authors.affiliation: Department of Neurology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.
authors.forename: Myrthe E
authors.initials: ME
authors.lastname: de Koning
authors.affiliation: Department of Neuropsychology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Jacoba M
authors.initials: JM
authors.lastname: Spikman
authors.affiliation: Department of Neurology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.
authors.forename: Joukje
authors.initials: J
authors.lastname: van der Naalt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001924:Brain Concussion / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000523:psychology*; D001931:Brain Mapping; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D009426:Netherlands; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000503:physiopathology; D009483:Neuropsychological Tests; D011446:Prospective Studies; D055815:Young Adult
keywords: Brain networks; Mild traumatic brain injury; Post-concussive complaints; Working memory