Evaluation of Canadian CT head injury rule performance among patients with seizure- and non-seizure-related head injuries: A pilot study

INTRODUCTION: Canadian CT Head Injury Rule (CTHR) is used to evaluate the necessity of a computed tomography (CT) scan in patients with TBI suspicion. Despite known negative effects of epilepsy on brain structural integrity, patients with SRHI are still assessed with CTHR. OBJECTIVES: Assess the prognostic efficiency of CTHR in seizure-related and non-seizure-related head injury. Secondarily, identify CTHR criteria significantly associated with acute CT findings in SRHI patients. METHODS: Data on 124 patients with SRHIs were extracted from the medical records followed by 169 non-SRHI admissions. Head injuries prior to seizures, age below 16 years-old, patients on blood thinners, and lack of CT imaging were considered exclusion criteria. Propensity score matching equalized both cohorts at 118 cases. Sensitivity, specificity, and the associated likelihood ratios were calculated. CTHR criteria were analysed to identify TBI predictors in SRHIs. RESULTS: Significantly greater number of non-SRHI patients had positive CTHR classification compared to SRHI. No significant difference was found in the number of positive CT classifications. In the non-SHRI group, CTHR was associated with a LR+ of 1.29 and a LR- of 0. In contrast, within the SHRI group, CTHR demonstrated an LR+ of 1.72 and an LR- of 0.34. GCS < 15 and signs of basilar skull fracture were significantly correlated with positive CT findings in this cohort. CONCLUSION: Our findings emphasize the need for tailored tools for managing SRHIs. Future research should focus on the development of more sensitive and specific guidelines by exploring factors correlated with acute head CT findings.