Cognitive outcome in children with infantile spasms using a standardized treatment protocol. A five-year longitudinal study.

AIM: To evaluate the long-term developmental trajectory of children with infantile spasms (IS) and identify the clinical protective and risk factors associated with their cognitive outcome.

METHODS

We analyzed the five-year follow-up results of 41 children (13 female) from the previously published cohort (n = 68) recruited in a multicenter randomized controlled trial for 2-years, examining the effect of an adjunctive therapy (Flunarizine) on standardized IS treatment. The children were subsequently monitored in an open-label study for additional 3 years.  The Vineland Adaptive Behavior Scale, second edition, and either the Stanford-Binet Intelligence Scale, Fifth Edition (SB5) or the Bayley Scales of Infant Development, second edition (BSID-II) were used as cognitive outcome measures.

RESULTS

Etiology was the strongest predictor of outcome. Children with no identified etiology (NIE) showed a progressive improvement of cognitive functions, mostly occurring between 2 and 5 years post-diagnosis.  Conversely, symptomatic etiology was predictive of poorer cognitive outcome. Developmental delay, other seizure types (before and after IS diagnosis), and persistent electroencephalographic abnormalities following treatment were predictive of poor cognitive outcome.

INTERPRETATION: Given the 5-year cognitive improvement, children with IS should undergo a developmental assessment before school entry. Factors influencing their cognitive outcome emphasize the importance of thorough investigation and evidence-based treatment.