Mild traumatic brain injury (mTBI) is the most prevalent type of traumatic brain injury. Ongoing work has shown mTBI to be a major contributor to the development of cognitive and behavioral learning deficit. Currently there are no clear objective means to diagnose mTBI. Hypothesis: We hypothesize that post-mTBI inflammatory signals will be altered and that these alterations will correlate with levels of neurocognitive performance providing a biomarker basis for the degree of cognitive deficit resulting from mTBI. Objective: This study will identify blood-borne immune markers that provide a reliable basis for assessing severity of mTBI and expected recovery through the characterization of peripheral cytokine signature profiles as they change in time post-mTBI. Aim 1: To quantitatively assess the temporal changes in mTBI altered neurocognitive performance and symptoms. Aim 2: To conduct a comprehensive survey of cytokines in blood plasma and characterize the temporal evolution of these signature patterns following mTBI. Aim 3: To link the evolution in cytokine signatures with the recovery of neurocognitive performance post-mTBI and use these associations to develop a blood-borne biomarker framework for the assessing mTBI severity. Methods: Subjects (n=12) suffering from mTBI will be recruited from the Nova Southeastern University's Sports Medicine Clinic, and will be cognitively assessed using the Immediate Post-Concussion Assessment and Cognitive Testing instrument at three time points (within 2, 4 and 6 days of injury). At each assessment blood draws will be taken and analyzed at the Institute for Neuro-Immune Medicine to assess immune activation via direct cytokine measures. Using systems biology analysis techniques neurocognitive, symptom and cytokine measures will be analyzed for underlying association patterns. Outcome: This research will result in a candidate set of blood-borne immune biomarkers supporting mTBI diagnosis and prognosis on the basis of injury severity that are compatible with psychological based evaluations of cognitive performance.