Abstracts

RATIONALE: A group of children with Infantile Spasms (IS) treated with ACTH will relapse. We attempt to better define this group with respect to presentation, treatment, subsequent response to therapy, and outcome. METHODS: 32 children with IS treated with ACTH over a 5 year period at Children's Hospital (Boston) were identified. 30/32 were included in the analysis. Responders were defined as those who had complete resolution of clinical IS and hypsarrhythmia (or variant). IS relapse was based on either EEG evidence of hypsarrhythmia (or variant) or clinically on seizure description. The group of children who initially responded and then relapsed (Rel+) was compared to the group of children who responded and did not relapse (Rel-) with respect to presentation, treatment of initial IS episode, and outcome. RESULTS: 22/30 responded to the initial ACTH therapy (10 are symptomatic; 12 are cryptogenic). 6/22 had a relapse of IS (3 are symptomatic; 3 are cryptogenic). In the Rel+ group, 5/6 were treated with a second course of ACTH. 2/5 responded (both cryptogenic). One of these remains seizure free. The other had a second relapse 9 months after the second treatment course, is currently treated again with ACTH, and remains seizure free. However, follow-up has been short in both of these cases. The 3 non-responders (one with Aicardi syndrome and the other two with tuberous sclerosis) have remained refractory to subsequent therapy. In the Rel- group, 8/16 are currently taking an AED; only 3/16 (2 are symptomatic; 1 is cryptogenic) have had subsequent seizures. No difference between the Rel+ and Rel- groups was found with respect to the presentation (etiology, age at IS onset, development, previous seizure history, MRI findings) and treatment (delay to ACTH treatment, initial dose of ACTH, length of initial treatment, and length of taper). All 30 children currently have some degree of developmental delay. CONCLUSIONS: The Rel+ group had an equal number of symptomatic and cryptogenic patients. We found a lower rate of response to a second course of treatment and a greater likelihood of refractory seizures in the Rel+ group. No factors predictive of IS relapse after initial successful treatment with ACTH were identified.