Symptom response following acute bouts of exercise in concussed and non-concussed individuals - A systematic narrative review

Background: Athletes suspected of being concussed are frequently evaluated on the side-line for self-reported symptoms which guide subsequent management and return-to-play decisions. Concussion-like symptoms have been shown to be influenced by prior participation in physical activity; however, the potential contribution of acute exercise on symptoms is not well understood. Objective: The purpose of this study was to systematically review the literature in order to further understand the acute effects of exercise on documented self-reported symptoms in both concussed and non-concussed individuals. Design: Systematic narrative review. Methods: Nine electronic databases were systematically searched using keywords and MeSH terms that included; self-reported symptoms, sports-related concussion, brain concussion, exercise and athletic injuries. In addition, an extensive search of the grey literature was conducted. Results: Of the 785 articles retrieved, only five met the inclusion criteria comprising a total of 295 concussed and non-concussed participants. In general, the mean symptom scores increased from pre-exercise to post-exercise levels immediately following acute bouts of exercise in both concussed and non-concussed individuals. Conclusion: Although the symptom scores increased following exercise in both concussed and non-concussed participants, this increase was only maintained for a relatively short duration. Thus, the application to real world situation is still to be established. (C) 2013 Elsevier Ltd. All rights reserved.