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

✍ Scribed by Dr. Antonino Uncini; Dr. Maria Santoro; Dr. Massimo Corbo; Dr. Alessandra Lugaresi; Dr. Norman Latov

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 571 KB
• Volume: 16
• Category: Article
• ISSN: 0148-639X
• DOI: 10.1002/mus.880160606

✦ Synopsis

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-GMl 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.