Seizure Outcomes After Radiosurgery for Cerebral Arteriovenous Malformations: An Updated Systematic Review and Meta-Analysis

Abstract

Objective: The seizure outcomes for patients with brain arteriovenous malformations (AVM) who undergo intervention with stereotactic radiosurgery (SRS) are incompletely understood. We sought to determine, in a systematic review and meta-analysis, the rates of seizure control after SRS for patients with AVM-associated seizures and identify predictive factors.

Methods: We performed a systematic review of PubMed and MEDLINE databases from January 1987 to January 2018, in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies reporting post-SRS outcomes data for ≥5 patients with AVM-associated seizures were included. The seizure outcomes and factors associated with seizure freedom were evaluated using meta-analysis.

Results: A total of 27 studies, comprising 4826 patients, met the inclusion criteria for analysis. One or more seizures occurred in 1456 of 4826 patients (34.7% [26.0-43.9%]), and the mean follow-up was 48 ± 7 months. Seizure control (seizure freedom or seizure improvement) was achieved in 910 of 1312 patients (73.1% [66.9-78.9%]). Seizure freedom was achieved in 597 of 1245 patients (55.7% [44.5-66.6%]). Of 259 patients with seizure freedom, cessation of antiepileptic drugs was achieved in 175 patients (67.3% [46.3-85.1%]). AVM obliteration (odds ratio [OR] 4.61; P < 0.001), shorter seizure duration (OR 6.80; P < 0.001), generalized seizure type (OR 2.27; P = 0.007), and previous AVM hemorrhage (OR 5.10; P < 0.001) were significantly associated with seizure freedom.

Conclusions: SRS affords seizure control to the majority of patients with AVM-associated seizures, and approximately two thirds of those with seizure freedom are able cease anticonvulsants. Nidal obliteration appears to improve the likelihood of seizure freedom, and thus remains the primary goal of intervention with SRS.

Keywords: Arteriovenous malformation; Epilepsy; Outcome; Radiosurgery; Review; Seizure; Stereotactic.