Validate whether simple quantitative measures of CT-based lobar contusion volumes associate with post-traumatic epilepsy (PTE).

PTE is a life-altering complication of traumatic brain injury (TBI). Most quantitative imaging studies of PTE risk focus on advanced modality imaging using MRI, while the use of lower-cost CT imaging remains underexplored. Given the routine use and accessibility of CT imaging in TBI, we aimed to evaluate associations between quantitative metrics of region-specific CT-based contusion volume and PTE development.

In our retrospective cohort of TBI admitted to a tertiary care center between 2015-2021, we identified and matched 33 PTE patients with 33 non-PTE controls on TBI severity (admission GCS), age, and sex. Using Horos Imaging software, two trained blinded non-physician raters independently assessed contusion volumes by lobe and hemisphere in all 66 patients. Discrepancies ≥5cc were adjudicated by a third physician rater; volume measurements were then averaged. Independent sample t-tests were performed for all volume comparisons and Fisher’s Exact test was used for location comparisons.

Our results indicate that total fronto-temporal contusion volume was significantly greater in PTE patients compared to control patients (31.3±55.4cm³ vs. 5.4±12.1cm³; p=0.012). Regionally, PTE patients had significantly increased left frontal contusion volume (5.1±13.6cm³ vs. 0.05±0.3cm³; p=0.038) and increased left temporal contusion volume (6.8±17.7cm³ vs. 0.1±0.3cm³; p=0.035). However, no relationship between contusion location itself and PTE was observed (Fisher exact, p=0.600).

Our results independently validate preliminary associations (Sanders et al. ANA poster 2021) between higher contusion volume and PTE development further supporting the importance of CT imaging as a readily available quantitative PTE prognostication tool.