Childhood-Onset Multifocal Motor Neuropathy with IgM Antibodies to Gangliosides GM1: A Case Report with Poor Outcome

Abstract

Abstract Background Multifocal motor neuropathy (MMN) is a slowly progressive motor neuropathy characterized by asymmetric muscle weakness without sensory involvement. Typically, MMN respond completely to treatment with intravenous immunoglobulin (IVIg). MMN is even rarer in the pediatric population, where only five patients have been reported up to now. Case Report We discuss the 3-year follow-up of a 13-year-old girl with MMN who was positive for IgM antibodies to gangliosides GM1. She was diagnosed with MMN in accordance with the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) criteria. Serological studies revealed that she tested positive for IgM antibodies to GM1. She underwent intravenous methylprednisolone followed by an oral prednisone taper, intravenous immunoglobulin (IVIg), plasma exchange followed by IVIG and prednisone and Rituximab. No improvement was referred. At the present, she shows flaccid tetraplegia, facial diplegia, and bulbar cranial nerve palsy. Conclusion Although childhood onset MMN is rare, most patients reported in literature respond to IVIg treatment. In a few cases, however, IVIg can be ineffective. In our patient, IVIg as well as treatment with prednisolone, plasma exchange and rituximab have failed.