The multifocal motor neuropathy (MMN) is a rare peripheral disorder characterized by persistent conduction blocks confined to motor axons at sites not prone to compression. Anti-GM1 ganglioside IgM antibodies at high titres are found in patients with MMN; in some of these patients the therapeutic reduction of anti-GM1 antibody levels induced by immunosuppressive agents is associated to clinical improvement. This fact suggests a possible pathogenetic role of these antibodies in the MMN. We describe two atypical cases of MMN simulating a motor neuron disease. In the first patient the symptoms were slowly progressive with bulbar muscle impairment, generalized weakness, muscular atrophy with cramps and fasciculations. Marked apraxia of the superior facial district with an inability to perform voluntary saccades and eye closure and speech impairment with reduction of verbal fluency were also evident. Multifocal conduction blocks resulted from EMG examination and high titres of anti-GM1 antibodies were present in serum. In the second patient the clinical symptoms started with a progressive paresis of the left brachial plexus followed by controlateral plexus involvement and successive weakness of neck muscles. Multiple conduction motor blocks were evident in the arms; the legs were relatively spared, with only one block in the left peroneal nerve. Anti-GM1 antibodies were absent. The spectrum of the clinical and laboratoristic characteristics of the MMN is quite wide. A precise definition of different subgroups in this syndrome is needed to clarify the pathogenetic mechanism and to develop specific therapeutic approaches.
|Translated title of the contribution||Atypical findings in two cases of multifocal motor neuropathy|
|Number of pages||10|
|Journal||Rivista di Neurobiologia|
|Publication status||Published - 1994|
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