Echoes of Concussion: Behavioral and neural changes after injury

Mild traumatic brain injury (mTBI), or concussion, accounts for 85% of all TBIs. After several weeks of recovery in which individuals typically return to activities of daily living and there is an assumption that cognitive status returns to premorbid levels. However, this assumption merits revisiting. Given the heterogeneity of mTBI, it could be challenging to identify consistent impairments at the group level. Tasks that measure executive functions, such as working memory (WM), are well-positioned to reveal persistent deficits because executive functions are dependent on the success of earlier processing stages (e.g., perception, attention). In particular, WM has been shown to depend on broad frontoparietal networks supported by the superior longitudinal fasciculus, which is commonly damaged in TBI. To better understand the cognitive and neural deficits associated with mTBI, we tested performance using a change detection tasks at a set size of 3, visual and verbal 3-back task with numbers and letters, neuropsychological assessments, resting state electroencephalography (rs-EEG), and resting state functional magnetic resonance imaging (rs-fMRI). The data reveal deficits in the change detection task, 3-back task, neuropsychological assessments, and rs-fMRI but no changes in rs-EEG modularity, global efficiency, and local efficiency were detected. Overall, we observe behavioral deficits in subacute mTBI and those with a history mTBI with some evidence of disconnection syndrome present in functional connectivity