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.