Seizure outcome in infantile spasms--a retrospective study

Purpose: Prior to the United Kingdom Infantile Spasms Study (UKISS), our practice was to initiate vigabatrin for infantile spasms. However, since then we tend to use steroids as first-line agent for infantile spasms. Herein we compare seizure-free outcomes in children with infantile spasms on steroid therapy or vigabatrin therapy.

Methods: This was a retrospective case study over 8 years of children with infantile spasms who were treated at our center. A positive response to therapy was defined as a two-week spasm-free interval.

Key findings: Of the 98 children presenting to us, 75 were included for this study. The ratio of cryptogenic to symptomatic spasms was 24:51. The response rate for steroid therapy was 61.1% and 42.5% for vigabatrin. Cessation of spasms was achieved faster in the group receiving steroids. Both groups had similar relapse rates. Steroids had significantly better response in the cryptogenic group, whereas in the symptomatic group both the medications were equally effective. Cryptogenic spasms have a better neurodevelopmental outcome. Early introduction of therapy for spasms did not predict a good neurodevelopmental outcome. Seventy-eight percent of children with spasms had seizures of other types at 12 months follow-up.

Significance: At our center, steroids are now the preferred choice for initial therapy of infantile spasms. This is likely to have been a beneficial change, particularly for children with cryptogenic spasms. Spasms in 25% of the patients tend to be refractory, and the majority of patients from the cohort continue to have epilepsy with motor and cognitive disabilities.