Multifocal motor neuropathy.
OBJECTIVE
To conduct a critical review of recent studies on the clinical and therapeutic aspects of multifocal motor neuropathy, and to analyse their implications for patient management.


RESULTS
Recent studies have contributed to defining the specific position of multifocal motor neuropathy within the spectrum of chronic immune-mediated polyneuropathies. One study compared features of this condition with multifocal acquired demyelinating sensory and motor neuropathy, while others have focused on pathological alterations at the site of conduction blocks. A further study described six new cases of multifocal acquired motor neuropathy, which should be considered as a variant of multifocal motor neuropathy. Several Cochrane reviews and review articles have shown evidence of the efficacy of intravenous immunoglobulins in the treatment of multifocal motor neuropathy. The issue of long-term intravenous immunoglobulins in multifocal motor neuropathy, however, has yielded controversial results. Two studies have shown progressive motor deterioration in most patients, correlated with electrophysiological signs indicative of axonal degeneration, while a third study found signs of sustained clinical and electrophysiological improvement after a mean follow up of 7.25 years.


CONCLUSIONS
Multifocal motor neuropathy is a distinct clinical entity that differs from chronic inflammatory demyelinating polyradiculoneuropathy and multifocal acquired demyelinating sensory and motor neuropathy, although they share some electrophysiological characteristics. Although the aetiology remains unsolved, frequent association with high-titer antibodies against ganglioside GM1, together with an often positive response to intravenous immunoglobulins further support an autoimmune mechanism. New therapeutic strategies are required, however, that focus on the effects and the costs of treatment over long-term follow up.
Léger
Jean-Marc
JM
consutation de Pathologie Neuro-Musculaire, Babinski Building, Salpêtrière Hospital, Paris, France. jean-marc.leger@psl.ap-hop-paris.fr
Behin
Anthony
A
D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D016472:Motor Neuron Disease / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D011115:Polyneuropathies / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy
D016756:Immunoglobulins, Intravenous