TACKLE concussion study: an observational study of post-concussion biomarker and neuroimaging progression in adolescent male school sports-related concussion.

Introduction
Sports-related concussion (SRC) is an established research topic in the context of sport professionals suffering from mild traumatic brain injury (mTBI), but there is scant investigation of SRC arising in school-aged athletes. Effective management of SRC in adolescents is especially dependent on obtaining an understanding of its pathophysiology and the multifaceted nature of recovery. In this planned observational study, we shall investigate the associations among multimodal data comprising blood-based and saliva-based biomarkers, diffusion tensor imaging (DTI), quantified susceptibility imaging (QSM), resting state functional connectivity MRI (rsfMRI) and cognitive testing in school rugby players with a conventional diagnosis of concussion. Our objective is to map out a natural history of the post-concussion injury and recovery process as measured by diverse biomarkers.Methods And Analysis
This prospective cohort study will enrol 450 male adolescents who participate in sports (including rugby, basketball and swimming). We shall quantify blood biomarker levels (total tau, neurofilament light, glial fibrillar acidic protein and ubiquitin C-terminal hydrolase-L1), white matter integrity on DTI, cerebral venous oxygen saturation on QSM, connectivity metrics on rsfMRI and cognitive performance after SRC. We conduct measurements at pre-injury baseline measure and post-SRC at four to five pivotal times: day 1 (day of injury), 3, 6, 13 and 21 (if symptoms persist) post-concussion. Using mixed-effects and trajectory modelling, we shall assess biomarker trajectories.We have secured ethical approval for this study from The University of Queensland's Human Research Ethics Committee, Queensland. We shall inform participants and/or their guardians verbally and in writing of the study's scope and procedures as a condition for informed consent. The dissemination of findings shall entail peer-reviewed publications and presentations at national and international conferences and via research and clinical networks. Completion of this study should provide a clearer understanding of anatomic and functional outcomes in adolescents with sports-related concussion.Benefits Of The Study
The multimodal investigation of a cohort of adolescents suffering from concussion in the context of community sports should offer broad insight into the effects of mTBI on the developing brain.