Long-term weekly adrenocorticotropic hormone therapy for relapsed infantile spasms

Infantile spasms (IS) is the most recognized epileptic encephalopathy in early infancy, resulting in poor cognitive outcome.Adrenocorticotropic hormone (ACTH) therapy is the first-line therapy for IS, but the relapse rate is high.Relapse after initial ACTH therapy is a poor prognostic factor for longterm seizure control and outcome of cognitive function.Recently, several studies have reported on the long-lasting maintenance of the positive effects produced by an initial course of ACTH by using long-term weekly ACTH therapy for relapsed IS.Here, we review the clinical characteristics of five previously reported cases.Epileptic spasms and hypsarrhythmia remained completely resolved during the extended ACTH therapy and did not recur after ACTH discontinuation in all cases.Furthermore, no cognitive or neurodevelopment deterioration was observed, and no serious adverse events occurred in any patient.In conclusion, this therapy appears safe and may lead to improved psychomotor development.We believe that it may be a good alternative therapy when frequent relapses occur after a favorable response to an initial course of conventional ACTH therapy.However, further studies are required to examine the risks and benefits of this therapy for relapsed IS in a large population and in countries in addition to Japan.