Predictors of seizure freedom in the surgical treatment of supratentorial cavernous malformations

OBJECT: Seizures are the most common presenting symptom of supratentorial cerebral cavernous malformations (CCMs) and progress to medically refractory epilepsy in 40% of patients. Predictors of seizure freedom in the resection of CCMs are incompletely understood. METHODS: The authors systematically reviewed the published literature on seizure freedom following the resection of supratentorial CCMs in patients presenting with seizures. Seizure outcomes were stratified across 12 potential prognostic variables. A total of 1226 patients with supratentorial CCMs causing seizures were identified across 31 predominantly retrospective studies; 361 patients had medically refractory epilepsy. RESULTS: Seventy-five percent of the patients were seizure free after microsurgical lesion removal, whereas 25% continued to have seizures. All patients had had preoperative seizures and > 6 months of postoperative follow-up. Modifiable predictors of postoperative seizure freedom included gross-total resection (OR 36.6, 95% CI 8.5-157.5) and surgery within 1 year of symptom onset (OR 1.83, 95% CI 1.30-2.58). Additional prognostic indicators of a favorable outcome were a CCM size < 1.5 cm (OR 15.4, 95% CI 5.2-45.4), the absence of multiple CCMs (OR 2.02, 95% CI 1.13-3.60), medically controlled seizures (OR 2.38, 95% CI 1.29-4.39), and the lack of secondarily generalized seizures (OR 3.33, 95% CI 2.09-5.30). Other factors, including extended resection of the hemosiderin ring, were not significantly predictive. CONCLUSIONS: In the surgical treatment of supratentorial CCMs, gross-total resection and early operative intervention may improve seizure outcome. While surgery should not be considered the first-line treatment for CCM-related epilepsy, it is important to understand the variables associated with seizure freedom in CCM resection given the considerable morbidity and diminished quality of life associated with epilepsy.