Adrenocorticotropic hormone controls infantile spasms independently of cortisol stimulation

Infantile spasms constitute a severe seizure disorder unresponsive to standard anticonvulsants. Both prednisone and adrenocorticotropic hormone (ACTH) have produced remission of seizures in some patients. The mechanisms of action of these hormones are not known. Eight infants with infantile spasms were treated with prednisone for 2 weeks. This controlled the seizures in two patients. In the remaining six patients, prednisone was continued and ACTH was added. This treatment produced cessation of spasms in four patients. Serum prednisone and cortisol were measured at a number of points during treatment. In infants receiving prednisone and then prednisone plus ACTH, serum cortisol was suppressed to about one-quarter of baseline levels with the initiation of prednisone, and remained suppressed during ACTH administration. We conclude that ACTH can exert its effect on infantile spasms in the setting of adrenal suppression, and can act without stimulating endogenous cortisol production. A CNS site of action is suggested and should be sought.