Sports-Related Concussion: Advances in Diagnosis, Biomarkers, and Long-Term Outcomes

Sports-related concussion (SRC) is a form of mild traumatic brain injury caused by biomechanical forces, commonly sustained during contact and collision sports. Although symptoms often resolve within weeks, a subset of athletes experience persistent impairment, and repeated exposure may increase the risk of long-term neurodegenerative and psychiatric outcomes. This review synthesizes data from over 30 peer-reviewed studies published between 2000 and 2025, evaluating advances in clinical diagnosis, biomarker development, neuroimaging, and long-term consequences of SRC. Current diagnostic protocols emphasize multimodal sideline assessment using tools such as SCAT6, Standardized Assessment of Concussion, Balance Error Scoring System, and the King-Devick test. While these tools demonstrate high sensitivity, their specificity remains moderate, and no single method can independently confirm SRC. Emerging blood-based biomarkers, particularly glial fibrillary acidic protein and neurofilament light chain, show promise for acute injury detection and prognosis but remain investigational. Advanced neuroimaging techniques, including diffusion tensor imaging and tau PET, have revealed microstructural and functional changes even when conventional scans are normal. A meta-analysis of five major cohort studies (n > 20,000) indicates that athletes with a history of multiple SRCs have a 2.52-fold higher risk of later-life neurocognitive disorder (95% CI: 1.26–5.04), although heterogeneity across populations remains high. Funnel plot asymmetry suggests possible publication bias. Overall, the evidence supports a dose–response relationship between SRC and long-term outcomes. Continued development of objective diagnostic tools and longitudinal studies are essential to improve care, guide policy, and reduce cumulative risk.