S100 and cognitive impairment after mild traumatic brain injury

Objective: The aim of this study was to explore the relationship between the proteins S100B and S100A1B and symptoms and signs of cognitive impairment for 3 months after mild traumatic brain injury (MTBI). Methods: Serum concentrations of S100A1B and S100B were examined in a prospective cohort study of patients with MTBI and a Glasgow Coma Scale score of 14 or 15. Cognitive performance was assessed by repeated computerized neuropsychological testing and an extended neuropsychological test. Symptoms were assessed using the Rivermead Post-Concussion Symptoms Questionnaire. Results: Concentrations of S100B and S100A1B were above cut-off in 31% and 48% respectively. Eight percent of the patients had signs of cognitive impairment according to the computerized neuropsychological tests and 30% according to the extended test. Symptoms of cognitive impairment were reported by 44% of the patients on the first day post-injury and by 26% at 3 months. No significant associations between S100B or S100A1B concentrations and symptoms or signs of cognitive impairment were found. Conclusion: Abnormal S100 serum concentrations and symptoms or signs of cognitive impairment were not significantly associated in patients with MTBI and a Glasgow Coma Scale score of 14 or 15.