Infantile spasms in Down syndrome: a report of 5 cases and review of the literature.

Five patients with Down syndrome (DS) and infantile spasms were examined in a four-year interval. Previous reports of this association have been infrequent except during experimental treatment with 5-hydroxytryptophan, a precursor of serotonin. Malformations of the brain in DS are associated with an increased incidence of epilepsy, and both gross and cytoarchitectural anomalies have been described. The severity and distribution of these central nervous system anomalies presumably predispose to the infantile spasms. The contribution of altered serotonin metabolism is uncertain.