The electrodiagnostic findings in polyneuropathies associated with IgM monoclonal gammopathies.
Electrodiagnostic studies were analyzed in patients with neuropathy associated with IgM monoclonal proteins, 7 with anti-myelin associated glycoprotein reactivity (MAG) and 7 nonreactive to MAG. The findings were distinctly different in the two groups. The electrodiagnostic studies of all the MAG-reactive patients had demyelinating features with slowing of conduction and prolonged distal latencies while only one of the MAG-nonreactive patients had a demyelinating pattern. In fact, the MAG-nonreactive patients were a heterogeneous group, both electrodiagnostically and clinically. This study supports the concept that MAG-reactive polyneuropathy is demyelinating in type, and is caused by the activity of the IgM M-protein directed at an antigen in the myelin sheath.
Department of Neurology, Tufts Medical School, Boston, Massachusetts.
J J
JJ
Kelly
D000328:Adult; D000368:Aged; D003711:Demyelinating Diseases / Q000175:diagnosis / Q000209:etiology; D004568:Electrodiagnosis; D005260:Female; D006801:Humans; D006942:Hypergammaglobulinemia / Q000150:complications*; D007075:Immunoglobulin M; D008297:Male; D008875:Middle Aged; D009185:Myelin Proteins / Q000276:immunology*; D018992:Myelin-Associated Glycoprotein; D009431:Neural Conduction / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000175:diagnosis* / Q000209:etiology
D007075:Immunoglobulin M; D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein