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. 2002 Jun;72(6):761–766. doi: 10.1136/jnnp.72.6.761

Multifocal motor neuropathy: clinical and immunological features and response to IVIg in relation to the presence and degree of motor conduction block

E Nobile-Orazio 1, A Cappellari 1, N Meucci 1, M Carpo 1, F Terenghi 1, A Bersano 1, A Priori 1, S Barbieri 1, G Scarlato 1
PMCID: PMC1737926  PMID: 12023421

Abstract

Objective: To determine whether patients with clinically typical multifocal motor neuropathy (MMN) with or without definite or probable conduction block (CB) differ in terms of clinical presentation, immunological findings, or response to treatment with intravenous immunoglobulin (IVIg).

Methods: 23 consecutive patients were studied with the typical clinical features of MMN, consisting of a progressive multineuropathic motor impairment with minimal or no sensory loss. In 14 patients, electrophysiological studies disclosed the presence of a definite or probable CB according to the criteria proposed by the American Association of Electrodiagnostic Medicine (AAEM) in at least one motor nerve. Six patients had possible CB, defined as a degree of CB 10% less than that required by the AAEM for probable CB, while no CB was detected in three patients.

Results: Patients with possible CB did not differ from those with a definite or probable CB in terms of age at disease onset (mean 38.8 v 38.2 years, respectively), distribution and severity of limb weakness, clinical impairment (mean Rankin score 2.2 in both), and frequency of antiganglioside antibodies (33% v 29%). Patients with possible CB had a longer mean disease duration (9 v 5.9 years, p < 0.05) and a less frequent consistent response to IVIg (67% v 86%) than those with a definite or probable CB. Patients without a detectable CB had a similar frequency of antiganglioside antibodies (33%) but had a longer disease duration (20.3 years), greater impairment (Rankin score 2.7), and more frequent signs of axonal degeneration (41% of examined motor nerves) than patients with CB (13–15%, p < 0.005). Only one patient without detectable CB (33%) consistently improved with IVIg.

Conclusions: Patients with possible CB were clinically and immunologically indistinguishable from those with definite or probable CB, albeit with a slightly less frequent response to IVIg. This finding suggests that failure to fulfil AAEM criteria for CB in patients with otherwise clinically typical MMN should not preclude this diagnosis and consequently a treatment trial with IVIg. Whether the longer duration and greater severity of the disease and more frequent axonal impairment in patients without detectable CB than in those with CB explain their lower response to IVIg remains to be established.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. American Association of Electrodiagnostic Medicine. Olney R. K. Guidelines in electrodiagnostic medicine. Consensus criteria for the diagnosis of partial conduction block. Muscle Nerve Suppl. 1999;8:S225–S229. [PubMed] [Google Scholar]
  2. Biessels G. J., Franssen H., van den Berg L. H., Gibson A., Kappelle L. J., Venables G. S., Wokke J. H. Multifocal motor neuropathy. J Neurol. 1997 Mar;244(3):143–152. doi: 10.1007/s004150050065. [DOI] [PubMed] [Google Scholar]
  3. Cappellari A., Nobile-Orazio E., Meucci N., Levi Minzi G., Scarlato G., Barbieri S. Criteria for early detection of conduction block in multifocal motor neuropathy (MMN): a study based on control populations and follow-up of MMN patients. J Neurol. 1997 Oct;244(10):625–630. doi: 10.1007/s004150050157. [DOI] [PubMed] [Google Scholar]
  4. Carpo M., Allaria S., Scarlato G., Nobile-Orazio E. Marginally improved detection of GM1 antibodies by Covalink ELISA in multifocal motor neuropathy. Neurology. 1999 Dec 10;53(9):2206–2207. doi: 10.1212/wnl.53.9.2206. [DOI] [PubMed] [Google Scholar]
  5. Chaudhry V., Corse A. M., Cornblath D. R., Kuncl R. W., Drachman D. B., Freimer M. L., Miller R. G., Griffin J. W. Multifocal motor neuropathy: response to human immune globulin. Ann Neurol. 1993 Mar;33(3):237–242. doi: 10.1002/ana.410330303. [DOI] [PubMed] [Google Scholar]
  6. Federico P., Zochodne D. W., Hahn A. F., Brown W. F., Feasby T. E. Multifocal motor neuropathy improved by IVIg: randomized, double-blind, placebo-controlled study. Neurology. 2000 Nov 14;55(9):1256–1262. doi: 10.1212/wnl.55.9.1256. [DOI] [PubMed] [Google Scholar]
  7. Hughes P. R. 79(th) ENMC International Workshop: multifocal motor neuropathy. 14-15 April 2000, Hilversum, The Netherlands. Neuromuscul Disord. 2001 Apr;11(3):309–314. doi: 10.1016/s0960-8966(00)00191-7. [DOI] [PubMed] [Google Scholar]
  8. Katz J. S., Wolfe G. I., Bryan W. W., Jackson C. E., Amato A. A., Barohn R. J. Electrophysiologic findings in multifocal motor neuropathy. Neurology. 1997 Mar;48(3):700–707. doi: 10.1212/wnl.48.3.700. [DOI] [PubMed] [Google Scholar]
  9. Kornberg A. J., Pestronk A. Chronic motor neuropathies: diagnosis, therapy, and pathogenesis. Ann Neurol. 1995 May;37 (Suppl 1):S43–S50. doi: 10.1002/ana.410370706. [DOI] [PubMed] [Google Scholar]
  10. Kornberg A. J., Pestronk A. The clinical and diagnostic role of anti-GM1 antibody testing. Muscle Nerve. 1994 Jan;17(1):100–104. doi: 10.1002/mus.880170115. [DOI] [PubMed] [Google Scholar]
  11. Lange D. J., Trojaborg W., McDonald T. D., Blake D. M. Persistent and transient "conduction block" in motor neuron diseases. Muscle Nerve. 1993 Sep;16(9):896–903. doi: 10.1002/mus.880160903. [DOI] [PubMed] [Google Scholar]
  12. Léger J. M., Chassande B., Musset L., Meininger V., Bouche P., Baumann N. Intravenous immunoglobulin therapy in multifocal motor neuropathy: a double-blind, placebo-controlled study. Brain. 2001 Jan;124(Pt 1):145–153. doi: 10.1093/brain/124.1.145. [DOI] [PubMed] [Google Scholar]
  13. Meucci N., Cappellari A., Barbieri S., Scarlato G., Nobile-Orazio E. Long term effect of intravenous immunoglobulins and oral cyclophosphamide in multifocal motor neuropathy. J Neurol Neurosurg Psychiatry. 1997 Dec;63(6):765–769. doi: 10.1136/jnnp.63.6.765. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Nobile-Orazio E., Meucci N., Barbieri S., Carpo M., Scarlato G. High-dose intravenous immunoglobulin therapy in multifocal motor neuropathy. Neurology. 1993 Mar;43(3 Pt 1):537–544. doi: 10.1212/wnl.43.3_part_1.537. [DOI] [PubMed] [Google Scholar]
  15. Nobile-Orazio E. Multifocal motor neuropathy. J Neuroimmunol. 2001 Apr 2;115(1-2):4–18. doi: 10.1016/s0165-5728(01)00266-1. [DOI] [PubMed] [Google Scholar]
  16. Pakiam A. S., Parry G. J. Multifocal motor neuropathy without overt conduction block. Muscle Nerve. 1998 Feb;21(2):243–245. doi: 10.1002/(sici)1097-4598(199802)21:2<243::aid-mus14>3.0.co;2-2. [DOI] [PubMed] [Google Scholar]
  17. Parry G. J., Clarke S. Multifocal acquired demyelinating neuropathy masquerading as motor neuron disease. Muscle Nerve. 1988 Feb;11(2):103–107. doi: 10.1002/mus.880110203. [DOI] [PubMed] [Google Scholar]
  18. Pestronk A., Cornblath D. R., Ilyas A. A., Baba H., Quarles R. H., Griffin J. W., Alderson K., Adams R. N. A treatable multifocal motor neuropathy with antibodies to GM1 ganglioside. Ann Neurol. 1988 Jul;24(1):73–78. doi: 10.1002/ana.410240113. [DOI] [PubMed] [Google Scholar]
  19. Rhee E. K., England J. D., Sumner A. J. A computer simulation of conduction block: effects produced by actual block versus interphase cancellation. Ann Neurol. 1990 Aug;28(2):146–156. doi: 10.1002/ana.410280206. [DOI] [PubMed] [Google Scholar]
  20. Roth G., Rohr J., Magistris M. R., Ochsner F. Motor neuropathy with proximal multifocal persistent conduction block, fasciculations and myokymia. Evolution to tetraplegia. Eur Neurol. 1986;25(6):416–423. doi: 10.1159/000116045. [DOI] [PubMed] [Google Scholar]
  21. Sumner A. J. Separating motor neuron diseases from pure motor neuropathies. Multifocal motor neuropathy with persistent conduction block. Adv Neurol. 1991;56:399–403. [PubMed] [Google Scholar]
  22. Taylor B. V., Wright R. A., Harper C. M., Dyck P. J. Natural history of 46 patients with multifocal motor neuropathy with conduction block. Muscle Nerve. 2000 Jun;23(6):900–908. doi: 10.1002/(sici)1097-4598(200006)23:6<900::aid-mus9>3.0.co;2-y. [DOI] [PubMed] [Google Scholar]
  23. Van den Berg-Vos R. M., Franssen H., Wokke J. H., Van Es H. W., Van den Berg L. H. Multifocal motor neuropathy: diagnostic criteria that predict the response to immunoglobulin treatment. Ann Neurol. 2000 Dec;48(6):919–926. [PubMed] [Google Scholar]
  24. van Schaik I. N., Bossuyt P. M., Brand A., Vermeulen M. Diagnostic value of GM1 antibodies in motor neuron disorders and neuropathies: a meta-analysis. Neurology. 1995 Aug;45(8):1570–1577. doi: 10.1212/wnl.45.8.1570. [DOI] [PubMed] [Google Scholar]

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