Comparison of serum and cerebrospinal fluid protein S-100b levels after severe head injury and their prognostic importance.

BACKGROUND: This study aimed to compare serum and cerebrospinal fluid (CSF) S-100b protein levels after a severe head injury. The changes in serum S-100b and CSF S-100b concentrations were investigated as indicators of brain damage for patients suffering from severe head injuries. METHODS: The sample included 48 patients with Glasgow Coma Scale scores of 8 or below who had been admitted to the authors' emergency service soon after their severe head injury occurred. Both blood and CSF samples were taken within 1 to 11 hours after admission, then 24, 48, and 72 hours after the injury. Samples of CSF were taken using a ventricular catheter. The outcome was evaluated 6 to 9 months after hospital discharge using the Glasgow Outcome Scale. RESULTS: The overall mean serum S-100b concentration was 3.5 +/- 6.4 among the patients with unfavorable outcomes and 1.3 +/- 2.5 among those with favorable outcomes. These results were not statistically significant (p > 0.05). The overall mean CSF S-100b concentration was 62.2 +/- 21.8 among the patients with unfavorable outcomes and 21.8 +/- 17.7 among those with favorable outcomes. These results, however, were statistically significant (p < 0.05). CONCLUSION: The results show that CSF S-100b levels clearly are superior to serum S-100b levels for predicting outcome after severe head injury.