Are enlarged perivascular spaces a predictor of early post-traumatic seizures after traumatic brain injury?- A pilot study

OBJECTIVE: Post-traumatic epilepsy (PTE) is a significant long-term complication following traumatic brain injury (TBI), while early post-traumatic seizures (EPTS), occurring within the first week after TBI, are a critical risk factor that can elevate the likelihood of developing PTE later on. Here we investigate the potential of MRI-based enlarged perivascular space (ePVS) analysis as an imaging biomarker for acute in-hospital EPTS. METHODS: Forty patients who experienced a moderate-severe TBI with early post-traumatic seizures (EPTS+) (32.5% female, median age 52 years) and 88 patients without (EPTS-) (35.2% female, median age 53 years) were recruited from the Oslo University Hospital's head injury registry. PVS were measured on brain MRIs taken within one month post- TBI using an automated ePVS segmentation algorithm. The analysis included PVS count, volume, and asymmetry index (AI) across both hemispheres and vascular territories. Brain volume analysis was conducted using the FreeSurfer software suite, and PVS characteristics were compared between EPTS+ and EPTS- patients using non-parametric tests and generalized linear models. RESULTS: The study found no statistically significant differences in the number, volume, or asymmetry of ePVS between EPTS+ and EPTS- patients. Specifically, the median counts of ePVS and the volume fractions did not vary between the groups, indicating that ePVS did not correlate with the occurrence of EPTS in the studied cohort. CONCLUSION: Our findings suggest that ePVS may not be reliable biomarkers for predicting EPTS (after TBI). However, future longitudinal studies that track ePVS changes over time could better illuminate their relationship with PTE development. This approach may reveal critical mechanisms influencing seizure risk and identify potential intervention points for at-risk patients, ultimately enhancing strategies for managing TBI-related epilepsy.