AbstractObjectivesThis study aimed to investigate changes in three intrinsic functional connectivity networks (IFCNs; default mode (DMN), salience (SN), and task-positive networks (TPN)) in individuals who had sustained a mild traumatic brain injury (mTBI).MethodsResting-state functional magnetic resonance imaging (rs-fMRI) data was acquired from 27 mTBI patients with persistent post-concussive symptoms (PCS), along with 26 age- and sex-matched controls. These individuals were recruited from a Level-1 trauma centre, at least three months after a traumatic episode. IFCNs were established based on seed-to-voxel, region-of-interest (ROI) to ROI, and independent component analyses (ICA). Subsequently, we analyzed the relationship between functional connectivity and PCS.ResultsSeed-to-voxel analysis of rs-fMRI demonstrated decreased functional connectivity in the right lateral parietal lobe, part of the DMN, and increased functional connectivity in the supramarginal gyrus, part of the SN. Our TPN showed both hypo- and hyperconnectivity, dependent on seed location. Within network hypoconnectivity was observed in the visual network, also using group comparison. Using an ICA, we identified altered network functional connectivity in regions within four IFCNs (sensorimotor, visual, DMN, and dorsal attentional). A significant negative correlation between dorsal attentional network connectivity and behavioural symptoms score was also found.ConclusionsOur findings indicate that rs-fMRI may be of use clinically, in order to assess disrupted functional connectivity among IFCNs in mTBI patients. Improved mTBI diagnostic and prognostic information could be especially relevant for athletes looking to safely return to play, as well for individuals from the general population with persistent post-concussive symptoms months after injury, who hope to resume activity.
Longitudinal Changes of Caudate-Based Resting State Functional Connectivity in Mild Traumatic Brain Injury
