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 freedom from seizures in their surgical treatment remains underappreciated.
OBJECTIVE: To characterize risks factors for preoperative seizures and factors associated with postoperative freedom from seizures 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 preoperative seizures, and 23 (18%) with seizures progressed to medically refractory epilepsy. Seizures were associated with a history of AVM hemorrhage (relative risk, 6.65; 95% confidence interval [CI], 3.81-11.6), male sex (relative risk, 2.07; 95% CI, 1.26-3.39), and frontotemporal lesion location (relative risk, 1.75; 95% CI, 1.05-2.93). After resection, 96% of patients had a modified Engel class I outcome, characterized by freedom from seizures (80%) or only 1 postoperative seizure (16%; mean follow-up, 20.7 ± 2.3 months). Comparable rates of postoperative seizures were seen in patients with (7%) or without (3%) preoperative seizures. AVMs with deep artery perforators were significantly associated with postoperative seizures (hazard ratio, 4.35; 95% CI, 1.61-11.7).
CONCLUSION: In the microsurgical treatment of supratentorial AVMs, hemorrhage, male sex, and frontotemporal location are associated with higher rates of preoperative seizures, whereas deep artery perforators are associated with postoperative seizures. Achieving freedom from seizure is an important goal that can be achieved in the surgical treatment of AVMs because epilepsy can significantly diminish patient quality of life.
ABBREVIATIONS: AED, antiepileptic drug
AVM, arteriovenous malformation
CI, confidence interval
mRS, modified Rankin Scale
RR, relative risk
UCSF, University of California, San Francisco
*Department of Neurological Surgery
‡UCSF Center for Cerebrovascular Research
§Department of Anesthesia and Perioperative Care
‖Department of Epidemiology and Biostatistics, University of California, San Francisco, California
Correspondence: Dario J. Englot, MD, PhD, Department of Neurological Surgery, University of California, San Francisco, 505 Parnassus Ave, Room M779, San Francisco, CA 94143-0112. E-mail: firstname.lastname@example.org or email@example.com
Reprint requests: Michael T. Lawton, MD, 505 Parnassus Ave, Box 0112, San Francisco, CA 94143-0112. E-mail: LawtonM@neurosurg.ucsf.edu
Received June 2, 2011
Accepted April 25, 2012