Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disorder of the central nervous system (CNS). Serum immunoglobulin G autoantibodies (NMO-IgG) are identified in the majority of NMOSD patients. The Pediatric form presents before 18 years. Based on the similarity of clinical, neuroimaging, and laboratory characteristics of pediatric NMOSD to those of the adult form, the international panel suggested that adult criteria of NMOSD also are appropriate in pediatric patients. However, the proposed criteria need validation in pediatric patients. This strategy poses challenges to the study design in clinical trials in pediatric NMOSD patients.