ABSTRACT
OBJECTIVE: To determine whether serum neurogranin (NRGN), glial fibrillary acidic protein (GFAP), and calcium-binding protein S100 beta (S100B) levels are associated with traumatic intracranial lesions compared to computed tomography (CT) findings of patients with mild traumatic brain injury (mTBI). PATIENTS AND METHODS: The cross-sectional study cohort included 48 patients who were admitted to the Emergency Department with a complaint of mTBI, a Glasgow Coma Scale score of 14-15, and at least one symptom of head trauma (i.e., post-traumatic amnesia, nausea or vomiting, post-traumatic seizures, persistent headache, and transient loss of consciousness). Blood samples and CT scans were obtained for all patients within 4â¯h of injury. Age-matched patients without intracranial traumatic pathology (CT-) were recruited as a control group. Blood samples were measured for NRGN, GFAP, and S100B levels. RESULTS: Of 48 patients, 24 were CTâ¯+â¯and had significantly higher serum NRGN (5.79 vs. 2.95â¯ng/mL), GFAP (0.59 vs.0.36â¯ng/mL), and S100B (1.72 vs.0.73⯵g/L) levels than those who were CT- (pâ¯=â¯0.001, pâ¯=â¯0.026, and pâ¯<â¯0.001, respectively). ROC curves showed that NRGN, GFAP, and S100B levels were sufficient to distinguish traumatic brain injury in patients with mTBI. At the cut-off value for NRGN of 1.87 ng/mL, sensivity was 83.3%, and specificity was 58.3%. At the cut-off value for GFAP of 0.23 ng/mL, sensivity was 75% and specificity was 62.5%. The optimal cut-off value for S100B was 0.47 µg/L (95.8% sensitivity and 62.5% specificity). CONCLUSION: This is the first study to evaluate NRGN in human serum after mTBI. We confirmed that NRGN levels were significantly higher in CTâ¯+â¯patients than CT- patients in the mTBI patient population. Future studies of larger populations and different age groups (especially pediatric) can help reduce the number of CT scans as a reliable and noninvasive diagnostic tool for evaluating NRGN protein levels in mTBI patients with a low probability of intracranial lesions.