Most authorities recommend adrenocorticotropic hormone (ACTH) as the first line therapy for treatment of infantile spasms (IS).  Very few researchers have reported on the relative efficacy of synthetic ACTH (sACTH) versus natural ACTH (nACTH), however both are thought to be similarly effective. United States  (US) data reports a 55% response rate (IS freedom at 3 months post therapy) for nACTH, and United Kingdom data 76% for sACTH (tetracosactide) (using 40 international units-IU- for 2 weeks and then 60 IU if no response). Cosyntropin is an alternative synthetic ACTH available in the US.

After IRB approval, we performed a retrospective chart review of patients admitted to Arkansas Children’s Hospital (ACH) from September 2009 to December 2017. Analysis included 0-2 year old children diagnosed with IS and hypsarrhythmia on video EEG. We excluded those with Ohtahara syndrome or early myoclonic encephalopathy. We compared the response rate to various treatment regimes. Responders were divided into early responders (ER) – IS free < 2 weeks of therapy initiation and maintaining seizure freedom (SF); late responders (LR) - IS free after 2 weeks and maintaining SF.  Relapsers (R) did not maintain SF beyond 3 months. The remainder were non-responders (NR).

Of a total of 124 patients with IS, 41 had prior brain injury, 25 had migrational or other structural abnormalities, 24 had genetic etiologies, 11 had unknown etiology with developmental delay, and 23 had unknown etiology with normal development at diagnosis. A total 21 patients received CS, ranging from <50 IU per day to 100 IU per day. Of the 21 patients, 2 were ER, 1 was LR, 2 were R, and 16 were NR. Therefore, only 3 (14%) were responders and received 30-50 IU cosyntropin per day.

Cosyntropin does not appear to be effective in the treatment of IS.