Introduction: The aim of this study was to validate the S100B protein as a diagnostic tool for ruling out the presence of intracranial lesion (IL) after mild traumatic brain injury (mTBI). Subjects with a Glasgow Coma Scale (GCS) score of 15 and at least one neurological symptom post-trauma were selected from a large Spanish cohort.
Methods: A number of 260 patients with mTBI were enrolled. Blood samples were extracted within 6 h and CT scan performed within 24 h post-injury. Blood samples were also drawn from 18 healthy subjects.
Results: CT scan revealed the presence of IL in 22 patients (8.5%). Patients with mTBI had higher S100B serum levels (p = 0.008) than the healthy subjects (p < 0.001). The ROC analysis of S100B discriminated between patients with and without IL (AUC: 0.671; 95%CI: 0.574-0.769; p = 0.008). The multivariate analysis identified male gender (OR: 5.39; 95%CI: 1.45-20.10; p = 0.012), age > 65 (OR: 2.97; 95%CI: 1.04-8.44; p = 0.041) and S100B level >0.10 µg/L (OR: 7.93; 95%CI: 1.03-60.76; p = 0.046) as independent risk factors for IL in patients with mTBI.
Conclusion: Measurement of S100B within 6 h of mTBI accurately predicts risk of IL in patients with a GCS score of 15 and at least one neurological symptom.
Keywords: CT scan; S100B; Traumatic brain injury; biomarkers; brain damage.