Effects of levetiracetam on seizure frequency and neuropsychological impairments in children with refractory epilepsy with secondary bilateral synchrony

PURPOSE In epilepsy with continuous spikes and waves during slow sleep (CSWS), which is a representative epileptic syndrome of secondary bilateral synchrony (SBS), the urgent suppression of this electroencephalographic (EEG) abnormality may be necessary to prevent the progression of neuropsychological impairments. The purpose of this study was to determine the efficacy of levetiracetam (LEV) on SBS, seizure frequency, and neuropsychological impairments in children with refractory epilepsy. METHODS Eleven (seven male and four female) patients with refractory epilepsy with SBS on EEG, aged between 4.7 years and 11.3 years, were included in this study. After a 3-month baseline period, the patients were given LEV at an initial dose of 10mg/kg/day for the first week, followed at increments of 5mg/kg/day every week, up to 20mg/kg/day. The LEV dose was then adjusted up to a maximum of 60mg/kg/day, according to the clinician's judgment. EEG recordings and clinical evaluations were performed every 3 months, focusing on SBS. The occurrence of SBS was then scored, and the relationship between the score and the response to LEV treatment was evaluated. In comparison with the baseline SBS frequency, the EEG response to LEV treatment was classified, and responders were identified as having a ≥50% reduction in SBS frequency. In addition, in comparison with the baseline seizure frequency, response to LEV treatment was classified. Responders were identified as patients with complete cessation (100% seizure control) and a response of ≥50% reduction in seizures. Furthermore, neuropsychological impairments such as hyperactivity, impulsiveness, and inattention were evaluated before and after LEV treatment. RESULTS Eight patients (72.7%) were considered responders. In addition, all eight patients were also considered responders for clinical seizures. Furthermore, 7 of 8 (87.5%) patients with response showed decreased hyperactivity and impulsivity after LEV administration. CONCLUSIONS The present data clearly indicate the usefulness of LEV in reducing both SBS on EEG and seizure frequency. LEV represents an important addition to the treatments available for refractory childhood epilepsies with SBS on EEG.