The Effect of Levetiracetam on the Interictal EEG in Children with Refractory Epilepsy

BackgroundInterictal epileptiform discharges (IED) frequency is the most commonly studied interictal measure of ASM efficacy in patients with epilepsy, and IED suppression in a repeat pediatric EEG is usually interpreted as a reduced tendency towards seizures.ObjectiveTo assess whether the amplitude and morphology of IED can serve as surrogate measures of levetiracetam (LEV) efficacy in children with drug-resistant epilepsy.MethodsPatients with refractory epilepsy, who were treated with oral LEV during a 5-year period, and who had at least 24 h long-term video-EEG recording (LTVEEG) before LEV was initiated and after attaining maximal dosage, were retrospectively selected from the database of the pediatric epilepsy clinic and LTVEEG monitoring unit. IED kurtosis (degree of peakedness), skewness (degree of asymmetry), and below-curve-area (area of the IED) were estimated by a signal processing analysis program.ResultsIED analysis in 20 patients aged 3.6 months to 15 years at maximal LEV dosage revealed increased kurtosis, increased skewness positivity and decreased below-curve-area compared to pre-treatment values. Visual analysis revealed a mean IED amplitude decrease in 30% of the patients, mainly in patients with generalized seizures. Neither the changes in IED measures nor the decrease of the visually determined IED amplitude correlated with decreased seizure frequency.ConclusionsIED amplitude, kurtosis, skewness and below-curve-area were not correlated with seizure outcome after LEV initiation. Further studies with larger samples and additional seizure outcome measures are warranted.