Changes in brain activation measured by functional Near-Infrared Spectroscopy associated with continuing to play following sport-related concussion among adolescent athletes

Athletes who continue to play following sport-related concussion (SRC) have worse clinical outcomes compared to those removed from play immediately. This prospective study examined brain activation (i.e., oxygenated hemoglobin concentration [HbO2]), using functional near-infrared spectroscopy (fNIRS), in 20 adolescent athletes who either continued to play (PLAYED) or were immediately removed (REMOVED) following SRC. A linear mixed effects model found the PLAYED group demonstrated an increase of [HbO2] in the left hemisphere at the initial visit (pFDR<.001) and the REMOVED group had a reduction in [HbO2] in the right hemisphere at clinical recovery (pFDR=0.024). There was a significant group*timepoint interaction (pFDR<0.011), in which the PLAYED group had greater increase in [HbO2] in the left hemisphere at the initial visit compared with the REMOVED group, but no differences at clinical recovery. Athletes who remain in play following SRC exhibited more pronounced brain hyperactivation, which may be associated with worse clinical recovery outcomes.