Abstracts

Rationale: Infantile spasms (IS) are a form of epilepsy which remains difficult to treat and refractory to many conventional medications. The current standard of care in the US, ACTH, is effective in only 50-67% of patients and is associated with significant toxicities, so there is a need for alternative treatments. Levetiracetam (LEV) is a medication which has shown efficacy for other forms of epilepsy, but there is little data regarding its use for IS. This study is a retrospective analysis of all cases of IS over a 9-year period in our institution for which LEV was used either as initial treatment or as an add-on therapy after failure of ACTH or other medications. Methods: A database search was performed, identifying all cases of IS treated in our child neurology clinic from 1999-2008. A chart review was performed, and the following data for each case was collected: age of onset of IS, age of diagnosis, etiology if known, initial treatment and clinical response, all subsequent treatments added for patients with poor initial response, and age of resolution of IS. Treatment response was defined as a complete, sustained cessation of IS without recurrence for the following 12 months, with or without the presence of other seizures. Results: A database search identified 47 children with IS. From this group, sufficient data for analysis was available for 43 cases. Of these 43 cases, 13 received LEV for treatment of IS, including 3 who received LEV as initial monotherapy (one cryptogenic, two symptomatic) and 10 who received LEV as an add-on therapy after failing other treatments (one cryptogenic, nine symptomatic). Overall, 4 of the 13 patients responded to LEV, representing a response rate of 30.8%, with time to resolution ranging from 2 to 20 days (mean 9 days). None of the three receiving LEV as initial monotherapy showed a sustained response, although one patient did have complete cessation of IS for ten weeks before relapse. All three subsequently responded to ACTH. Of the 10 who received LEV as add-on treatment, 4 had a sustained response, while 6 failed treatment. One of the responders began receiving LEV during a course of treatment with ACTH, so it is unclear whether cessation of IS was due to LEV, ACTH, or the combination. The 4 responders had previously failed 2-3 other therapies including one ACTH failure, while the 6 non-responders had failed 2-7 other therapies including three ACTH failures. 2 of these 6 later responded to other medications (one to topiramate and one to lamotrigine); four remained refractory to all treatments attempted. No complications related to LEV occurred in any patient. Conclusions: LEV is a safe and effective therapy for some patients with IS, leading to complete resolution of IS in 30.8% of patients in this series. While all responders had symptomatic IS, the number of patients with cryptogenic IS was too small to draw conclusions regarding the utility of LEV for this group. LEV should be considered as a useful addition to the armamentarium of options for patients with refractory IS. Further studies are needed to determine its utility as initial therapy.