Summary:Purpose: To evaluate the outcome of children with cryptogenic infantile spasms treated with high-dose synthetic adrenocorticotropic hormone (ACTH) and the relation between early treatment, within 1 month of onset, and outcome.Methods: We assessed the long-term cognitive and seizure outcomes of 37 patients with cryptogenic infantile spasms (onset, age 3 to 9 months) receiving standardized treatment regimen of high-dose tetracosactide depot, 1 mg IM every 48 h for 2 weeks, with a subsequent 8-to 10-week slow taper and followed by oral prednisone, 10 mg/day for a month, with a subsequent slow taper for 5 months or until the infant reached the age of 1 year, whichever came later. Development was assessed before treatment. Seizure outcomes were followed up prospectively. Cognitive outcomes were determined after 6 to 21 years and analyzed in relation to treatment lag and pretreatment regression.

3-Methylglutaconic aciduria has been described in two distinct syndromes. In one there was deficient 3-methylglutaconyl coenzyme A hydratase in fibroblast extracts where the only clinical manifestation was retarded speech development. In the second syndrome, the enzyme activity was normal but prominent neurological deterioration was noted. We describe two siblings with 3-methylglutaconic aciduria with normal enzyme activity who had choreoathetoid movements, optic atrophy, and mild developmental delay. The boy demonstrated developmental improvement in his second year of life, and his sister developed well, with normal school performance. These patients represent a new clinical variant of the second syndrome with a relatively favorable prognosis.