Abstracts

Rationale: Levetiracetam (LEV) has been shown to be an effective adjunctive agent in the treatment of partial epilepsy. Its beneficial effect for the treatment of idiopathic generalized epilepsy and its electrographic correlate has been reported. Limited, but emerging, data are available regarding those patients with symptomatic epilepsies. There are no current data linking spike wave density (SWD=spikes/hr) and seizure frequency in pediatric patients with symptomatic epilepsy on LEV.Methods: We conducted a retrospective review of pediatric patients on LEV admitted to our institution between 2001 and 2005 for prolonged video electroencephalographic (EEG) evaluation. Data regarding underlying diagnosis, seizure type and severity, and response to treatment with LEV were obtained. The EEG records were reviewed and four samples of awake and sleep background for each patient were evaluated for SWD, and averaged.Results: Data from 48 patients (32 females, 16 males) with symptomatic epilepsy (4 partial, 44 generalized) were extracted. The median age was 9 years (range 2 ½ months to 18 years). All patients were on LEV. The mean dose of LEV used was 95 mg/kg/day (range 15mg/kg/day to 288 mg/kg/day). The majority (38/48) had LEV used as add-on therapy to other anti-epileptic agents. In addition, 3 patients were treated with intravenous immunoglobulin, 2 patients were dosed with prednisone, and 3 were on the ketogenic diet. The mean SWD of the 48 patients on LEV was 807/hr, not significantly different when compared to a similar cohort not on LEV (654/hr) (p>0.05). Of these 48 patients, 14 had EEG telemetries performed before and after placement on LEV. The median duration of time on LEV before EEG evaluation was repeated was 12 months (range 2 weeks to 4 years). Among these, 4 (29%) exhibited a greater than 50% reduction in seizure frequency, 1 (7%) experienced a less than 50% reduction in seizures, and 7 (50%) had no significant response to LEV. None of these 14 patients were seizure free. One patient reported a worsening of seizures on LEV. The seizure types most responsive to treatment were generalized tonic clonic, generalized myoclonic, and generalized tonic. Other seizure types including atypical absence (5/14) and generalized atonic (3/14) were less responsive. LEV did not appear to be beneficial for patients with electrical status epilepticus in slow wave sleep (ESES). There was no consistent correlation between trends in SWD and seizure control with LEV treatment.Conclusions: In this retrospective pediatric study, the SWD of patients with symptomatic epilepsy did not appear to be consistently reduced on LEV and did not predictably correlate with seizure control. Although none of these patients were seizure free on LEV, 36% reported some benefit; 80% of these reported a seizure reduction of greater than 50%. This study suggests that pediatric patients with symptomatic epilepsies including generalized tonic clonic, generalized myoclonic, and generalized tonic seizures, may still benefit from LEV as add-on therapy despite continued active SWD on EEG. (Funding provided by UCB Pharma, Inc.)