Serum S100B protein in early management of patients after mild traumatic brain injury

Neuronal protein S100B assays are available now with a perspective of being an early screening tool for serious intracranial injury. The aim of the study was to correlate early S100B measurements and initial CCT findings in the patients sustaining mild traumatic brain injury (MTBI).

The prospective study included patients of all ages with a history of MTBI. CCT scans and venous blood sampling for S100B analysis were performed within 6 h after injury. Levels of S100B above 0.1 ng/ml (S100B+) and any CCT detectable trauma-relevant intracranial lesions were considered positive (CCT+).

A series of 102 patients were involved in the study. CCT+ scans were present in eighteen (17.6%) and CCT- scans in 84 (82.4%) patients. There were 74 (72.5%) patients in S100B+ and 28 (27.5%) in S100B- group. Sensitivity of S100B assay attained 83.3% with a negative predictive value of 89.3%. Three patients from CCT+ group had negative plasma level of S100B. Two of them required surgical treatment.

S100B serum protein marker seems to be an unrealiable screening tool for determination of an intracranial injury risk group due to low sensitivity and negative predictive value seen from samples taken greater than 3 h after an MTBI.