Thelansis

 Multifocal motor neuropathy (MMN), also known as multifocal motor neuropathy with conduction block (MMNCB), is a rare and acquired form of motor neuropathy characterized by progressive asymmetric weakness without sensory involvement. Immune-mediated mechanisms are believed to be the underlying cause of the disease, as evidenced by the high prevalence of serum IgM anti-GM1 antibodies in affected individuals and the favourable response to treatment with intravenous immunoglobulin (IVIG). The concentration of GM1, a ganglioside found in the myelin of motor nerves, is higher in motor nerves than in sensory nerves, which may explain the selective motor involvement in MMN. The conduction block seen in electrophysiological studies in MMN is thought to be caused by anti-GM1 antibodies, which disrupt the function of sodium and potassium channels at the nodes of Ranvier, leading to decreased action potential propagation and reduced conduction velocity. Differential diagnoses of MMN include ...