Predictive factors of epilepsy in a cohort of brain arteriovenous malformation patients with a 5-year follow-up.

Background and aims: Data on factors associated with new-onset epilepsy in the follow-up of patients with brain arteriovenous malformations (BAVM) are scarce. We aimed to characterize the baseline patient and BAVM characteristics related to epilepsy and the predictive factors of new-onset epilepsy in BAVM patients during their follow-up.

Patients and methods: We retrospectively analyzed 200 BAVM patients treated between 2000 and 2023. We used univariate and multivariate analyses to assess the association between baseline characteristics and seizures. The risk of developing seizures during follow-up was estimated using nonparametric survival analysis for interval-censored data.

Results: In the present cohort, 90/200 patients (45%) had epilepsy at baseline. Patients with epilepsy were predominantly men (71.1%), and alcohol users (18.8%), and presented with BAVM located more often in the frontal lobe (55.6%) as compared to patients without epilepsy (40%, 7.4%, 23.6% respectively). Male gender was associated with higher prevalence of seizures at inclusion (OR 3.81 [95%CI, 1.77; 8.24]), while headaches (OR 0.19 [95% CI, 0.09; 0.41]), focal deficit (OR 0.22 [0.09; 0.49]) and BAVM occipital localization (OR 0.16 [95% CI, 0.05; 0.47]) remained associated with lower prevalence of epilepsy at inclusion. Among patients without epilepsy at baseline, 20.6% had new-onset epilepsy after five years. Baseline predictors of seizure occurrence included ruptured BAVM (HR 3.77 [95%CI 1.50; 9.44]) and surgery (HR 7.75, 95%CI, [2.04; 29.45]).

Conclusions: For patients with newly diagnosed BAVM, male gender, and frontal topography were baseline characteristics associated with a higher risk of epilepsy. Among patients without epilepsy, ruptured BAVM and surgery at baseline were predictors of epilepsy at five years follow-up.