Hocke, Lia MariaDuszynski, Chris C.Debert, Chantel T.Dleikan, DianeDunn, Jeff F.2018-10-262018-10-262018-06-01Hocke, L. M., Duszynski, C. C., Debert, C. T., Dleikan, D., & Dunn, J. F. (2018). Reduced functional connectivity in adults with persistent post-concussion symptoms - a functional near-infrared spectroscopy study. "Journal of Neurotrauma", 35, 1-9. https:// doi.org/10.1089/neu.2017.5365.0897-7151http://hdl.handle.net/1880/108923Concussion, or mild traumatic brain injury (mTBI), accounts for ∼80% of all TBIs across North America. The majority of mTBI patients recover within days to weeks; however, 14-36% of the time, acute mTBI symptoms persist for months or even years and develop into persistent post-concussion symptoms (PPCS). There is a need to find biomarkers in patients with PPCS, to improve prognostic ability and to provide insight into the pathophysiology underlying chronic symptoms. Recent research has pointed toward impaired network integrity and cortical communication as a biomarker. In this study we investigated functional near-infrared spectroscopy (fNIRS) as a technique to assess cortical communication deficits in adults with PPCS. Specifically, we aimed to identify cortical communication patterns in prefrontal and motor areas during rest and task, in adult patients with persistent symptoms. We found that (1) the PPCS group showed reduced connectivity compared with healthy controls, (2) increased symptom severity correlated with reduced coherence, and (3) connectivity differences were best distinguishable during task and in particular during the working memory task (n-back task) in the right and left dorsolateral prefrontal cortex (DLPFC). These data show that reduced brain communication may be associated with the pathophysiology of mTBI and that fNIRS, with a relatively simple acquisition paradigm, may provide a useful biomarker of this injury.enThis Open Access article is distributed under the terms of the Creative Commons License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly creditedhttps://creativecommons.org/licenses/by/4.0DLPFCconcussionfNIRSfunctional connectivitymTBIworking memory taskjournal article10.1089/neu.2017.536510.11575/PRISM/33896