Head injury outcome prediction in the emergency department: a role for protein S-100B?

Background: Biochemical markers released after head injury may reflect the degree of brain damage, which is related to subsequent disability. If the serum level of a marker were found to be related to outcome, then earlier identification and intervention would be possible. Objective: To investigate the potential of the serum marker S-100B protein to predict the outcome after head injury. Methods: Blood samples for S-100B concentrations were taken from 148 adults within six hours of a head injury (initial Glasgow coma score 4-15). Patients were recruited from the emergency departments of four hospitals in Greater Manchester, United Kingdom. Outcome was assessed in 119 patients (80%) at one month using the extended Glasgow outcome scale (GOSE). Results: A significant inverse correlation between serum S-100B level and GOSE was found (Spearman's p = -0.349, p < 0.0001). A serum S-100B concentration of > 0.32 mug/l predicted severe disability (GOSE < 5) at one month with a sensitivity of 93% (95% confidence interval 68% to 100%), a specificity of 72% (54% to 79%), and a negative predictive value of 99% (93% to 100%). Conclusion: Serum S-100B concentration can be used in the emergency department to identify patients with head injury who are most likely to have a poor outcome at one month.