Background
Seizures are a common symptom of supratentorial arteriovenous malformations (AVMs), and uncontrolled epilepsy can considerably reduce patient quality-of-life. Potential risk factors for epilepsy in patients with AVMs are poorly understood, and the importance of achieving seizure-freedom in their surgical treatment remains under-appreciated.
Objective
To characterize risks factors for pre-operative seizures and factors associated with post-operative seizure-freedom in patients with surgically resected supratentorial AVMs.
Methods
We analyzed prospectively-collected patient data for 440 patients who underwent microsurgical resection of supratentorial AVMs at our institution.
Results
Among 440 patients with supratentorial AVMs, 130 (30%) experienced pre-operative seizures, and 23 (18%) individuals with seizures progressed to medically refractory epilepsy. Seizures were associated with a history of AVM hemorrhage (RR 6.65, 95% CI 3.81-11.6), male gender (RR 2.07, 95% CI 1.26-3.39), and frontotemporal lesion location (RR 1.75, 95% CI 1.05-2.93). After resection, 96% of patients had a modified Engel class I outcome, characterized by seizure-freedom (80%) or only one post-operative seizure (16%) (mean follow-up 20.7 ± 2.3 months). Comparable rates of post-operative seizures were seen in patients with (7%) or without (3%) pre-operative seizures. AVMs with deep artery perforators were significantly associated with post-operative seizures (HR 4.35, 95% CI 1.61-11.7).
Conclusion
In the microsurgical treatment of supratentorial AVMs, hemorrhage, male gender, and frontotemporal location are associated with higher rates of pre-operative seizures, while deep artery perforators are associated with post-operative seizures. Achieving seizure-freedom is an important goal that can be achieved in the surgical treatment of AVMs, as epilepsy can significantly diminish patient quality-of-life.