Predicting Functional Outcomes in Severe Traumatic Brain Injury

Abstract

Background: The objective of this prospective cohort study was to evaluate the role of serum S100B, along with other clinical and imaging parameters, in predicting functional outcome in severe traumatic brain injury (TBI). Methodology: We included 23 patients with severe TBI admitted within 48 h of injury. The Glasgow Coma Scale (GCS), pupil reactivity, and Marshall's computerized tomography grade were assessed at admission and serum levels of S100B were estimated at 48 h and 21 days post injury. ROC curve was generated to determine the cutoff value for S100B levels. Clinical data were analyzed to study their association in predicting the functional outcome as assessed by the Glasgow coma scale (GOS), Functional Independence Measure (FIM), and Modified Mini-Mental State Examination (3MS) at 6 months. Results: S100B levels above 1.37 μg/L at 48 h significantly predicted poor outcomes at 6 months as assessed by GOS (sensitivity of 64%, specificity of 83%, and likelihood ratio (LR) of 3.76), FIM (sensitivity of 75%, specificity of 85%, and LR of 5.0), and 3MS (sensitivity of 60%, specificity of 83%, and LR of 3.53). On linear regression analyses, GCS motor score at 96 h and S100B levels were independent predictors of GOS, FIM, and 3MS. The positive predictive value for poor outcome (GOS ≤3 or FIM <72 or 3MS <75) was 100% when S100B levels at 48 h ≥1.37 μg/L were combined with GCS motor scores at 96 h ≤3. Conclusion: S100B levels at 48 h post injury and GCS motor score at 96 h were significant predictors of long-term functional outcome in severe TBI.