Abstracts

Rationale: Open label studies have suggested that topiramate (TPM) may be effective as an add-on agent in the treatment of infantile spasms (IS). A recent study reported improved efficacy of IS control when a benzodiazepine (nitrazepam) was added to TPM. The objective of this study was to evaluate the efficacy and tolerability of TPM and clonazepam (CLZ) combination in the treatment of newly diagnosed IS. Methods: Retrospective chart review of children with newly diagnosed IS who were treated at our institution with TPM and CLZ combination as the initial therapy between 2003 and 2008. Results: Twelve children, 6 male and 6 female, with onset of IS between the ages of 1-20 months were included. Ten patients had symptomatic IS, and 2 cryptogenic. Mean daily dose of TPM was 13.1 mg/kg (range 5.5 -26.6 mg/kg), and that of CLZ 0.09 mg/kg (range 0.03 -0.14 mg/kg). Mean duration of follow-up was 18.7 months (range 1-52 months). Four patients (33%) became seizure free and 2 (17%) had more than 90% reduction in seizure frequency within 2-8 weeks (mean 5 weeks) of treatment. Hypsarrhythmia resolved in these responders with normalization of the EEG in 2. In 6 (50%) patients, IS persisted and their EEG remained hypsarrythmic in 5 and evolved into multifocal spikes in one. Side effects included crystalluria in one patient due to TPM and sialorrhea and stridor in another due to CLZ. Conclusions: The combination of TPM and CLZ appears to be effective and well tolerated in children with IS.