1 From the Pediatric Neurology (Z.O.Z.C., A.E.C., A.G.R., M.J.M.-G.), Cruces University Hospital, Bizkaia; Pediatric Neurology (A.F.-R.), Vall d'Hebron Institut de Recerca (VHIR), Hospital Universitari Vall d'Hebron, Vall d'Hebron Barcelona Hospital Campus, Barcelona; Pediatric Neurology (G.O.-C.), Hospital Universitari Parc de Taulí, Sabadell; and Pediatric Neuroimmunology Unit (T.A.), Neurology Department, Research Institute of Sant Joan de Deu Children's Hospital, University of Barcelona, Spain.