In recent years, in addition to neurological examination and neuroradiologic examinations, attempts have been made to assess the severity of post-traumatic brain injury and to obtain an early idea of patient prognosis using biochemical markers with a high degree of brain tissue specificity. One such enzyme is neuron-specific enolase (NSE). This study investigates the correlation between serum NSE levels, Glasgow Coma Score, and prognosis measured by Glasgow Outcome Scores in head trauma patients. This was a prospective study conducted with 80 trauma patients presenting to the Emergency Department. Patients were divided into four groups. The first group consisted of patients with general body trauma, but no head trauma. The second group had minor head trauma. The third group had moderate head trauma, and the fourth group had severe head trauma. The relationship between subjects' admission NSE levels and admission and discharge Glasgow Coma Scores (GCS) and Glasgow Outcome Scores (GOS) 1 month later was examined. A receiver operating characteristic (ROC) analysis was performed using a serum NSE cutoff level of 20.52 ng/mL and a GOS of 3 or less as the definition of poor neurologic outcome. There was a significant difference in the NSE levels between group 1 (general trauma) and group 3 (moderate head trauma). There was also a statistically significant difference in NSE levels between group 1 (general trauma) and group 4 (severe head trauma) (p < 0.05). There was a statistically significant inverse relationship between NSE levels and GOS as determined within groups 3 (moderate) and 4 (severe head trauma) (p < 0.05). When NSE levels were compared with admission GCS, it was found that GCS fell as NSE levels rose. There was no significant correlation between NSE and GCS within groups 3 (moderate) or 4 (severe). There was a statistically significant correlation within group 2 (mild) (p < 0.05). By ROC analysis, serum NSE was 87% sensitive and 82.1% specific in predicting poor neurologic outcome in the study patients. The area under the curve was 0.931. This study shows that initial serum NSE levels in moderate and severe head trauma patients correlate inversely with GOS 1 month later, but only within the moderate and severe head trauma groups. However, serum NSE was 87% sensitive and 82.1% specific in predicting poor neurologic outcome in all of the study patients. This derived cutoff value now needs to be prospectively validated. (C) 2010 Elsevier Inc.