IgM MGUS anti-MAG neuropathy with predominant muscle weakness and extensive muscle atrophy

Muscle Nerve. 2010 Sep;42(3):433-5. doi: 10.1002/mus.21741.


We report a patient with anti-myelin-associated glycoprotein (MAG) neuropathy, predominantly exhibiting severe motor symptoms, accompanied by extensive muscle atrophy mimicking Charcot-Marie-Tooth disease. Nerve conduction studies revealed mild retardation of motor conduction velocities and significant prolongation of distal latency. Sural nerve biopsy revealed widely spaced myelin and positive staining of myelinated fibers with an IgM antibody. Predominant motor symptoms with muscle atrophy can be one of the clinical manifestations of anti-MAG neuropathy.

Publication types

  • Case Reports

MeSH terms

  • Charcot-Marie-Tooth Disease / pathology
  • Diagnosis, Differential
  • Electrodiagnosis
  • Humans
  • Immunoglobulin M* / blood
  • Immunoglobulins, Intravenous / therapeutic use
  • Lower Extremity / pathology
  • Male
  • Middle Aged
  • Muscle Weakness / etiology
  • Muscle Weakness / pathology*
  • Muscle Weakness / therapy
  • Muscle, Skeletal / pathology*
  • Muscular Atrophy
  • Myelin-Associated Glycoprotein / immunology*
  • Neural Conduction / physiology
  • Paraproteinemias / pathology*
  • Paraproteinemias / therapy


  • Immunoglobulin M
  • Immunoglobulins, Intravenous
  • Myelin-Associated Glycoprotein