Intravenous immunoglobulin infusion in multifocal demyelinating motor neuropathy: a case report

The following report is a case of multifocal demyelinating motor neuropathy (MMN) presenting as a gradual development of asymmetric motor weakness without sensory involvement. Electrophysiological studies showed mainly a conduction block with normal or slightly slow nerve conduction velocity. Cerebrospinal fluid (CSF) protein and serum protein electrophoresis were normal, but serum IgM anti-GM1 ganglioside antibody was elevated. The patient had a poor response to steroid, plasmapheresis and chemotherapy with cyclophosphamide, but significant improvement was noted after intravenous immunoglobulin (IVIG) infusion. MMN is a potentially treatable condition which clinically mimics a motor neuron disease; if treatment with steroid, plasmapheresis and cyclophosphamide have failed, IVIG may be effective.