Axonal multifocal motor neuropathy without conduction block or other features of demyelination.
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.
Katz
J S
JS
Department of Neurology, Palo Alto VA Medical Center and Stanford University, Palo Alto, CA 94304, USA. jskatz@stanford.edu
Barohn
R J
RJ
Kojan
S
S
Wolfe
G I
GI
Nations
S P
SP
Saperstein
D S
DS
Amato
A A
AA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001369:Axons / Q000473:pathology*; D003711:Demyelinating Diseases / Q000175:diagnosis*; D004576:Electromyography; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D011115:Polyneuropathies / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D011241:Prednisone / Q000627:therapeutic use
D000893:Anti-Inflammatory Agents; D016756:Immunoglobulins, Intravenous; D011241:Prednisone