POMC and Lennox-Gastaut syndrome: To further explore the efficacy and safety of DEX in the treatment of IS and IS-related LGS, 51 patients who were diagnosed as having IS not caused by TSC and were nonresponsive to ACTH and/or prednisone were treated with DEX in the Children’s Hospital of Chongqing Medical University from May 2009 to June 2019 with the consent of parents.