Axonal multifocal motor neuropathy without conduction block or other features of demyelination.
Katz, J.S. MD; Barohn, R.J. MD; Kojan, S. MD; Wolfe, G.I. MD; Nations, S.P. MD; Saperstein, D.S. MD; Amato, A.A. MD
58(4):615-620, February 26, 2002.
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Background: Conduction block is considered an essential finding for the distinction between motor neuropathies and lower motor neuron disorders. Only a small number of reports describe patients with multifocal motor neuropathies who lack overt conduction block, although in these cases other features of demyelination still suggest the presence of a demyelinating disorder. In contrast, a purely axonal multifocal motor neuropathy has not been described.
Methods: This report describes nine patients with slowly or nonprogressive multifocal motor neuropathies who had purely axonal electrodiagnostic features.
Results: GM1 antibodies titers were normal in all nine cases. Six patients were treated with either prednisone or IV immunoglobulin and three showed convincing improvement.
Conclusions: These findings suggest an immune-mediated motor neuropathy with axonal electrophysiologic features that appears to be distinct from both multifocal motor neuropathy and established motor neuron disorders.
(C) 2002 American Academy of Neurology