Acute motor conduction block neuropathy or acute multifocal motor neuropathy: An attempt at a nosological systematization.

摘要

In the February issue, Manganelli et al. reported a patient with an asymmetrical acute motor neuropathy, persistent conduction blocks (CBs), IgM antibodies to GDla and GQ1b, and recovery in 24 weeks. Similar patients have been reported and variably classified as acute presentations of multifocal motor neuropathy (MMN) or variants of Guillain-Barre syndrome (GBS), thus inducing some terminological and nosological confusion. In 2003, we reported two patients who acutely developed symmetric weakness without sensory symptoms. Both patient had antecedent diarrhea, but Cam-pylobacter jejuni was isolated from one patient. Both patients carried high titers of IgG antibodies to GM1 and GDla. Electrophysiological studies showed reduction of distal compound muscle action potential (CMAP) amplitudes and partial motor CBs with normal sensory conductions, even across CB sites. Muscle weakness and CBs resolved in 2-5 weeks without development of excessive temporal dispersion of either distal or proximal CMAPs, suggesting a reversible immunome-diated conduction failure at the nodes of Ranvier without demyelination. Four similar patients have been reported; all had antecedent diarrhea, and three had evidence of recent C. jejuni infection (Table 1).