De Novo Epilepsy After Brain Arteriovenous Malformation Resection: A Study of 490 Patients in the Trinetx Analytics Network

Introduction: Although seizures are the second most common presenting symptom of brain arteriovenous malformations (BAVMs) after hemorrhage, there is a paucity of studies on postoperative de novo epilepsy after BAVM resection. We sought to assess the incidence and risk factors for de novo epilepsy after BAVM resection utilizing a national database.

Methods: Utilizing the TriNetX Analytics Network, we queried 490 cases from 70 health care organizations, from January 1st, 2003 to January 1st, 2021. We included patients of all ages who underwent supratentorial AVM resection (CPT:61682 and 61680) for the treatment of brain AVMs (ICD-10:Q28.2), presenting without seizures (ICD-10:G40, R56) on or before surgery and without being on antiepileptics (N03A) at least 1 day before surgery. The primary outcome was seizures manifesting at least 6 weeks after surgery. Patient characteristics and outcomes were compared between the cohorts with and without postoperative epilepsy, and subgroup analyses were conducted.

Results: Of the 490 patients (mean age of 48.1±19.6, 52% females) presenting without seizure who underwent BAVM resection during the 19-year period, 109 (22.2%) developed de novo epilepsy, with a one-year cumulative incidence of 14.8%. The epilepsy cohort was significantly younger than the non-epilepsy cohort (33±17.5 vs 39.4±19.7; p=0.0023; CPT:61624, 61626) with lower preoperative embolization rates (29% vs 40%; p=0.0452). There were no differences in sex, rupture/hemorrhage history (ICD-10:I60, I61), complexity (CPT:61682, 61680), and history of SRS. Subgroup analysis of the ruptured cohort revealed again that the patients that developed de novo epilepsy were younger (p=0.0017). Subgroup analysis of the unruptured cohort did not reveal baseline differences.

Conclusion : This national database analysis of 490 patients provides evidence that de novo epilepsy after brain AVM resection occurs at a one-year cumulative incidence of 14.8%, with a total of 22.2% developing de novo epilepsy. Younger age and lack of preoperative embolization may be risk factors.