Clinical outcome following medical treatment of cavernous malformation related epilepsy

Abstract

Purpose: The study was conducted to assess the long-term outcome of antiepileptic drug (AED) treatment in drug-na？ve patients with cavernous malformation related epilepsy (CRE) Methods: This is a retrospective, single-center, long-term observational study. Study included patients presented to the epilepsy clinic between 2000 and 2011 with previously untreated seizures related to MRI-proven, cavernous malformation (CM). All patients were followed-up for at least two years. Previous history of surgical or AEDs treatment, lack of EEG examination, no or only a single previous seizure were exclusion criteria. Seizure outcome was assessed on annual basis and patients were divided into two groups according to the success (Group 1) or failure (Group 2) to achieve terminal 1-year seizure remission (1-year TSR). Drug resistant epilepsy (DRE) was defined as two or more seizures per year after trial of two appropriate AEDs. Patients who had only one seizure during the previous one year were assigned as “epilepsy with rare seizure (ERS)”. Results: A total of 34 drug-na？ve patients (male 20) were included to the study. Mean duration of follow up was 5.88 ± 3.15 years. Pre-treatment baseline mean and median seizure frequencies were 4.93 ± 12.63 and 0.85 (1.92) episodes per month, respectively. 1-year TSR was achieved in 22 of 34 (64.7%) patients, nine (26.5%) patients were diagnosed as DRE, and three (8.82%) patients were as ERS. 1-year TSR was achieved in 18 of 34 (52.9%) patients by the first drug regimen and in additional four (11.8%) patients by the second drug regimen. Among 16 patients who failed to achieve 1-year TSR by the first drug monotherapy, three patients were ERS and did not undergo second drug trial. None of nine patients who failed to first two drug regimens did achieve 1-year TSR. Univariate analysis of multiple clinical variables disclosed that the location of CM in the temporal lobe was the only prognostic factor predicting a poor seizure outcome (p = 0.012). Conclusion: 1-year TSR was achieved in 64.7% of newly diagnosed patients with CRE in a long-term AEDs therapy. Failure to achieve seizure-freedom after adequate trials of two AEDs is strongly recommended as criteria for their referral to surgical treatment. However, for patients with temporal lobe CRE, a presurgical evaluation may be considered appropriate once they failed to an adequate trial of the first drug.