Abstracts

Rationale: To evaluate clinical factors that predict normalization of EEG at 6 months in a prospective study of subjects with new onset infantile spasms that were treated initially with vigabatrin and vitamin B6. This study is part of a larger randomized double blind multicenter clinical trial designed to evaluate the effect of flunarizine on long-term cognitive outcome in infantile spasms. Enrollment is complete, however the study has not been unblinded. Methods: 69 children in 7 Canadian tertiary care epilepsy centers with new onset infantile spasms were recruited over a 2-year period. All children received vigabatrin and vitamin B6 initially. Subjects were randomized to conventional treatment with flunarizine or placebo for 6 months. At 2 weeks those with persistent spasms and/or hypsarrythmia on video-EEG were treated with high dose ACTH. Children who failed ACTH at 1 month were converted to topiramate. In addition to video-EEG at 2 weeks, all subjects had routine sleep/wake EEG at baseline, 6, 12, 24 and 30 months. Subjects had detailed neuropsychological evaluation at baseline, 6, 24 and 30 months. Subjects had thorough evaluation for symptomatic etiologies including brain MRI.Results: The factors analyzed for this study were age at diagnosis of spasms, presence of asymmetric spasms or focal seizures, time to treatment, developmental level (as reported by study neurologist enrolling child), and etiology. A Fischer exact test was used to compare each risk factor. Factors associated with normal EEG at 6 months included: age of onset between 4 and 12 months ( p= 0.03), absence of developmental delay at baseline (p=0.03), idiopathic or cryptogenic etiology (p=0.01). Factors found to have no significance were time to onset of treatment (> or < 60 days) and whether subject had asymmetrical spasms and/or focal seizures. Conclusions: The risk factors associated with a normal EEG at 6 months of age included: typical age range at onset of spasms; normal development prior to treatment; and absence of a demonstrated etiology. These data may be helpful in providing families of children with infantile spasms treated with a similar protocol (vigabatrin followed by ACTH for non-responders) with a more precise prognosis.