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The electrodiagnostic findings in polyneuropathies associated with IgM monoclonal gammopathies
Author(s) -
Kelly John J.
Publication year - 1990
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880131205
Subject(s) - polyneuropathy , myelin associated glycoprotein , myelin sheath , medicine , monoclonal , myelin , polyradiculoneuropathy , immunology , guillain barre syndrome , nerve conduction , antigen , monoclonal antibody , pathology , antibody , central nervous system
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.