Abstracts

Rationale: There is little information about the clinical outcomes of medical treatment for cavernous malformation related epilepsy (CRE). This study was conducted to evaluate the clinical outcome of antiepileptic drug (AED) treatment in drug-naïve patients with CRE and to identify the optimal timing of epilepsy surgery of those patients. Methods: This study was a retrospective, single-center, and long-term observational study. MRI-proven, drug-naïve cavernous malformation patients presenting seizures between 2000 and 2011 were included. All patients were followed for at least two years. Previous history of surgical treatment, less than two years of follow-up period, lack of EEG exam, lack of seizure, lack of appropriate AED treatment was exclusion criteria. The patients were divided into two groups for comparison: Group I, seizure free during terminal one-year follow up; and Group II, not seizure free. Seizure outcome was assessed at annual basis, and drug resistant epilepsy was defined as continued seizures after two appropriate AEDs. Results: A total of 35 drug-naïve patients (male, 21) were included in the study. Average follow up duration was 5.74 years. Pre-treatment baseline (12 weeks) monthly seizure frequency was 4.79 ± 12.47. Terminal one-year seizure freedom rate was 65.7% and the percentage of drug resistant epilepsy was 25.7% after final follow up visit. The chance of prolonged seizure freedom by first drug regimen was 54.3% and additional chance of seizure freedom after the first regimen failure was 11.4%. None achieved seizure freedom after the two-drug failure. Location of the cavernous malformation in the temporal lobe was the only poor prognostic factor for the seizure outcome (p = 0.012). Conclusions: Seizure freedom was achieved in the 65.7% of the patient with CRE after long-term follow up. The surgical treatment should be considered for the CRE patients who failed to achieve seizure freedom after the second AED regimen.