From the Emergency Department to Follow-Up: Clinical Utility of Biomarkers in Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) remains a clinical challenge, particularly in cases with normal computed tomography (CT) findings but persistent or evolving symptoms. Conventional diagnostic approaches relying solely on clinical criteria and neuroimaging often lack adequate sensitivity and may lead to unnecessary radiation exposure. Recent advances in biomarker research have identified several blood-based proteins such as glial fibrillary acidic protein (GFAP), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), S100 calcium-binding protein B (S100B), Tau protein, neuron-specific enolase (NSE), and neurofilament light chain (NFL) as potential tools for improving diagnostic precision and guiding clinical decisions. In this study, we synthesize current evidence evaluating the diagnostic and prognostic utility of these biomarkers using sensitivity, specificity, negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC). GFAP and UCH-L1 have shown high sensitivity in detecting intracranial lesions and are now FDA-cleared for emergency department triage within 12 h of injury. While S100B remains widely investigated, its low specificity limits its application beyond select clinical scenarios (i.e., in patients without polytrauma). Additionally, Tau, NSE, and NFL are emerging as prognostic markers, with studies suggesting associations with persistent symptoms and long-term neurocognitive outcomes. Overall, the integration of biomarker-based data into clinical workflows may enhance early mTBI diagnosis, reduce reliance on imaging, and enable individualized follow-up and prognostic stratification. Future research should refine optimal sampling windows and explore multimarker panels to maximize diagnostic and prognostic performance.