Male gender associated with post-treatment seizure risk of pediatric arteriovenous malformation patients

BACKGROUND: Seizure risk has not been fully characterized in pediatric patients with arteriovenous malformations (AVMs). OBJECTIVE: To describe the progression and risk factors of post-treatment seizure in children with AVMs. METHODS: We retrospectively reviewed pediatric patients diagnosed with intracranial AVMs at our institution between 1990 and 2013. Clinical and angiographic variables were included in univariate and multivariate Cox proportional hazard models to explore risk factors associated with time-related seizure outcomes. The outcome event is defined as first seizure occurrence after initial treatment. Kaplan-Meier survival curve is depicted for each significant variable, and survival differences were confirmed by Log-rank test. RESULTS: We included 90 pediatric patients with complete data in our study cohort. Average age is 13.3 ± 3.8 years with 43.3% male patients. Thirty-seven patients had a hemorrhagic presentation, and 39 patients presented with seizure. Post-treatment seizure occurred in 33 patients (36.7%) over an average follow-up period of 8.1 ± 10.6 years; average time to onset is 5.3 ± 8.2 years, with partial seizures as the most common presentation. Multivariate Cox proportional hazard regression revealed seizure presentation (P = .005), male gender (P = .026), and nonconservative treatment modality to be significantly associated with earlier onset of post-treatment seizure after adjusting for AVM location and deep venous drainage.Overall annualized seizure risk is 7.4% for patients with pretreatment seizure, and 1.4% for those without. CONCLUSION: Risk of seizure persists after treatment in pediatric AVM patients. Seizure presentation, male gender, and nonconservative management are associated with increased risk of post-treatment seizure. Early identification of these risk factors provides important information for determining seizure management strategies.