Most authorities recommend adrenocorticotropic hormone (ACTH) as the first line therapy for treatment of infantile spasms (IS).  United States data reports a 55% response rate (IS freedom at 3 months post therapy) for natural ACTH (nACTH) and 39% for oral steroids while United Kingdom data 76% for synthetic ACTH (sACTH) and 70% for oral prednisolone. There are rare reports of dexamethasone use for treatment of IS with efficacy and relapse rate similar to that of nACTH.

After IRB approval, we performed a retrospective chart review of patients admitted to Arkansas Children’s Hospital from September 2009 to December 2017. Analysis included 0 -2 year old children diagnosed with infantile spasms 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 did not maintain SF beyond 3 months. The remainder were non-responders (NR).

Of a total of 124 children 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 were cryptogenic with normal development at diagnosis. There were a total of 5 patients treated with dexamethasone with an 80% responder rate (ER+LR). Four were ER and received 20 mg/m² dexamethasone daily for 3 days. One was NR and received 18.5 mg/m² of dexamethasone daily for 3 days.

Dexamethasone may be an effective treatment of IS, and further evaluation should be performed.