Abstracts

Rationale: To evaluate the long-term efficacy and tolerability of ethosuximide (ESX), valproic acid (VPA), and lamotrigine (LTG), as an initial monotherapy in childhood absence epilepsy. Methods: The medical record of 84 patients (30 boys, 54 girls) diagnosed as childhood absence epilepsy at Seoul National University Hospital were reviewed retrospectively. Patients with typical absence seizure, characteristic EEG finding (2.5~4Hz spike and wave complex), seizure onset between 4 and 10 years of age, and patients with minimum follow up duration after the treatment more than 1 year were included. Treatment outcome was defined as freedom from treatment failure including freedom from failure due to adverse events. Results: ESX, VPA, and LTG were administered to 35, 35, and 14 patients, respectively. After 3 months of treatment, the freedom from failure rates were 83% (29/35) in ESX group, 77% (27/35) in VPA group, and 50% (7/14) in LTG group. After 12 months, the freedom from failure rates were 80% (28/35) in ESX group, 69% (24/35) in VPA, 43% (6/14) in LTG group. The failure from adverse events was most frequently observed in VPA group (20%, 7/35) compared with ESX (14%, 5/35) and LTG (7%, 1/14) after 12 months. However, statistical analysis could not demonstrate these tendencies except the better treatment outcome in ESX group than LTG group. Conclusions: ESX seems to be more efficacious and tolerable than VPA and LTG in childhood absence epilepsy for long-term treatment. Relatively low efficacy of LTG and high adverse event rate of VPA should be considered when selecting antiepileptic drugs other than ESX.