The Infant Scalp Score: a validated tool to stratify risk of traumatic brain injury in infants with isolated scalp hematoma.

Objectives To validate the previously derived Infant Scalp Score (ISS) that uses clinical signs in infants with isolated scalp hematoma (ISH) after head trauma to stratify risk for clinically important traumatic brain injury (ciTBI) or TBI on computed tomography (CT). Methods Using the publicly available Pediatric Emergency Care Applied Research Network TBI dataset, we selected infants ≤ 1 year with GCS 14-15 who had ISH (defined as hematoma without other signs/symptoms of TBI). CT scans were obtained at the treating physician's discretion. We calculated ISS based on age, hematoma size and location (range 0-8) for each patient and calculated the sensitivity and specificity of the score for ciTBI and TBI on CT across a range of ISS cut-points. Results We included 1289 infants ≤ 1 year of whom 462 (36%) had CT performed. 12 had ciTBI and 59 had TBI on CT. An ISS cut-off ≥ 4 had sensitivity of 100% for ciTBI (95%CI, 0.74, 1.0) and TBI with specificity of 0.49 (95% CI 0.46, 0.51). An ISS cut-off of ≥ 5 had a sensitivity of 100% for ciTBI (95% CI, 0.74, 1.0) and specificity of 0.68 (0.66, 0.71), but missed 3 infants with TBI on CT (none of whom required intervention). The ROC curves for clinical score to detect ciTBI and TBI had AUC of 0.916 and 0.807, respectively. Conclusions The Infant Scalp Score accurately stratified risk for ciTBI and TBI on CT in infants with isolated scalp hematoma and is a useful tool to help guide clinical decision-making.