Is the Sport Concussion Assessment Tool 5th Edition a useful concussion assessment tool in head-injured patients presenting to the emergency department?

OBJECTIVE: Concussion is a common ED complaint, but diagnosis is challenging as there are no validated objective measures. Use of concussion tools derived from sports medicine is common, but these tools are not well validated in ED settings. The aim of this study was to assess the ability of the Sport Concussion Assessment Tool 5th Edition (SCAT5) to identify concussion in ED patients presenting following head injury. METHODS: We conducted a prospective observational study of head-injured adult patients presenting to ED between March and July 2021. ED diagnosis of concussion was used as the diagnostic standard, and we assessed the diagnostic performance of the SCAT5 test and its three subsections (Standardised Assessment of Concussion (SAC), Post-Concussion Symptom Scale (PCSS) and Modified Balance Error Scoring System (mBESS)) against this. RESULTS: Thirty-two head-injured participants were enrolled, 19 of whom had a discharge diagnosis of concussion, alongside 17 controls. Median time for SCAT5 testing was 21 (interquartile range 16-27) min. Fifteen (30.6%) participants were interrupted during testing. Area under the curve (AUC) (95% confidence interval) for the SAC, PCSS and mBESS were 0.51 (0.34-0.68), 0.92 (0.84-0.99) and 0.66 (0.47-0.85), respectively. Sensitivity and specificity of sections were as follows: entire SCAT5 (100.0%, 20.0%), SAC (48.1%, 60.0%), PCSS (89.7%, 85.0%) and mBESS (83.3%, 58.8%). Using PCSS alone would have identified 17 of 19 concussions. CONCLUSION: The SCAT5 test had a low specificity, was long and was frequently interrupted. We suggest it is not an ideal assessment to use in ED. The PCSS score performed well and was easy to complete. It may be useful as a standalone tool to simplify ED concussion identification.

Diagnostic performance of S100B as a rule-out test for intracranial pathology in head-injured patients presenting to the emergency department who meet NICE Head Injury Guideline criteria for CT-head scan.

BACKGROUND: Traumatic brain injury is a common ED presentation. CT-head utilisation is escalating, exacerbating resource pressure in the ED. The biomarker S100B could assist clinicians with CT-head decisions by excluding intracranial pathology. Diagnostic performance of S100B was assessed in patients meeting National Institute of Health and Clinical Excellence Head Injury Guideline (NICE HIG) criteria for CT-head within 6 and 24 hours of injury. METHODS: This multicentre prospective observational study included adult patients presenting to the ED with head injuries between May 2020 and June 2021. Informed consent was obtained from patients meeting NICE HIG CT-head criteria. A venous blood sample was collected and serum was tested for S100B using a Cobas Elecsys-S100 module; >0.1 µg/mL was the threshold used to indicate a positive test. Intracranial pathology reported on CT-head scan by the duty radiologist was used as the reference standard to review diagnostic performance. RESULTS: This study included 265 patients of whom 35 (13.2%) had positive CT-head findings. Within 6 hours of injury, sensitivity of S100B was 93.8% (95% CI 69.8% to 99.8%) and specificity was 30.8% (22.6% to 40.0%). Negative predictive value (NPV) was 97.3% (95% CI 84.2% to 99.6%) and area under the curve (AUC) was 0.73 (95% CI 0.61 to 0.85; p=0.003). Within 24 hours of injury, sensitivity was 82.9% (95% CI 66.4% to 93.44%) and specificity was 43.0% (95% CI 36.6% to 49.7%). NPV was 94.29% (95% CI 88.7% to 97.2%) and AUC was 0.65 (95% CI 0.56 to 0.74; p=0.046). Theoretically, use of S100B as a rule-out test would have reduced CT-head scans by 27.1% (95% CI 18.9% to 36.8%) within 6 hours and 37.4% (95% CI 32.0% to 47.2%) within 24 hours. The risk of missing a significant injury with this approach would have been 0.75% (95% CI 0.0% to 2.2%) within 6 hours and 2.3% (95% CI 0.5% to 4.1%) within 24 hours. CONCLUSION: Within 6 hours of injury, S100B performed well as a diagnostic test to exclude significant intracranial pathology in low-risk patients presenting with head injury. In theory, if used in addition to NICE HIGs, CT-head rates could reduce by one-quarter with a potential miss rate of <1%.