Epilepsy associated with cerebral cavernous malformations managed with stereotactic radiosurgery: an international, multicenter study

Objective: Stereotactic radiosurgery (SRS) has been proposed as an alternative to resection for epilepsy control in patients with cerebral cavernous malformations (CCM) located in critical areas. Methods: This multicentric, retrospective study evaluated seizure control in patients with a solitary CCM and a history of at least one seizure prior to SRS. Results: 109 patients (median age at diagnosis 28.9 years, interquartile range (IQR) 16.4 years] were included. Prior to SRS, 2 (1.8%) were seizure-free without medication, 35 (32.1%) were seizure-free with antiseizure medications (ASM), 17 (15.6%) experienced an improvement of at least 50% in seizure frequency/intensity with ASM, and 55 (50.5%) experienced an improvement of less than 50% in seizure frequency/intensity with ASM. At a median follow-up of 3.5 years post-SRS (IQR: 4.9), 52 (47.7%) patients were Engel class I, 13 (11.9%) class II, 17 (15.6%) class III, 22 (20.2%) class IVA or IVB and 5 (4.6%) class IVC. For the 72 patients who had seizures despite medication prior to SRS, a delay > 1.5 years between epilepsy presentation and SRS decreased the probability to become seizure-free, HR 0.25 (95% CI 0.09–0.66), p = 0.006. The probability of achieving Engel I at the last follow-up was 23.6 (95% CI 12.7–33.1) and 31.3% (95% CI 19.3–50.8) at 2 and 5 years respectively. 27 patients were considered as having drug-resistant epilepsy. At a median follow-up of 3.1 years (IQR: 4.7), 6 (22.2%) of them were Engel I, 3 (11.1%) Engel II, 7 (25.9%) Engel III, 8 (29.6%) Engel IVA or IVB and 3 (11.1%) Engel IVC. Interpretation: 47.7% of patients managed with SRS for solitary CCM presenting with seizures achieved Engel class I at the last follow-up.