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.