Conduction abnormalities induced by sera of patients with multifocal motor neuropathy and anti-GM1 antibodies

Muscle Nerve. 1993 Jun;16(6):610-5. doi: 10.1002/mus.880160606.


Increased titers of anti-GM1 antibodies have been associated with motor neuron disease and motor neuropathy with or without conduction block. To investigate the pathogenetic role of anti-GM1 antibodies we injected into rat tibial nerves sera from patients with multifocal motor neuropathy and conduction block (MMN) or progressive spinal muscular atrophy (PMA), both presenting anti-GM1 antibodies. Sera of patients with MMN produced reduction of amplitude and dispersion of compound muscle action potential from proximal stimulation. Morphometry revealed demyelination in 6.2% of fibers. Sera of patients with PMA did not produce clear-cut electrophysiological or morphological changes. Differential effects of sera from patients presenting high-titer anti-GM1 antibodies, but with distinct clinical syndromes, might depend on differences in anti-GM1 antibody affinity, valency, or ability to fix complement. Alternatively, circulating factors other than, or in addition to, anti-GM1 antibodies present in sera of patients with MMN, but not of PMA patients, might be responsible for conduction abnormalities and reproduce them after passive transfer.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies / pharmacology*
  • Demyelinating Diseases / etiology*
  • G(M1) Ganglioside / immunology
  • G(M1) Ganglioside / pharmacology*
  • Humans
  • Male
  • Motor Neuron Disease / immunology
  • Motor Neuron Disease / pathology
  • Motor Neuron Disease / physiopathology*
  • Muscular Atrophy, Spinal / immunology
  • Muscular Atrophy, Spinal / pathology
  • Muscular Atrophy, Spinal / physiopathology*
  • Neural Conduction / drug effects
  • Neural Conduction / physiology*
  • Rats
  • Rats, Sprague-Dawley
  • Tibial Nerve / drug effects
  • Tibial Nerve / pathology
  • Tibial Nerve / physiopathology


  • Antibodies
  • G(M1) Ganglioside