Demyelination and axonal loss in multifocal motor neuropathy: distribution and relation to weakness
| Autor: | G. H. Wieneke, L. H. van den Berg, R. M. Van den Berg-Vos, J.H.J. Wokke, J.T.H. van Asseldonk, H. Franssen |
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| Přispěvatelé: | Academic Medical Center |
| Rok vydání: | 2002 |
| Předmět: |
Adult
Male Weakness Axonal loss Neural Conduction Mismatch negativity Action Potentials Nerve Fibers Myelinated Degenerative disease Medicine Humans Axon Motor Neuron Disease Muscle Skeletal Leg Chi-Square Distribution business.industry Immunoglobulins Intravenous Sensory loss Anatomy Middle Aged medicine.disease Axons Electrophysiology medicine.anatomical_structure Logistic Models Arm Female Neurology (clinical) medicine.symptom business Multifocal motor neuropathy |
| Zdroj: | Brain, 126(1), 186-198. Oxford University Press |
| ISSN: | 0006-8950 |
| Popis: | Multifocal motor neuropathy (MMN) is characterized by a slowly progressive, asymmetric weakness of the limbs without sensory loss. The arms are usually affected to a greater extent than the legs, and distal muscles more than proximal muscles. The distribution of electrophysiological abnormalities and its correlation with weak muscle groups in MMN have not been investigated systematically. The aim of the present study was to assess whether electrophysiological abnormalities have a preferential or random distribution, whether electrophysiological abnormalities in a nerve correlate with weakness in the innervated muscles, and whether these results are relevant for the development of optimal electrodiagnostic protocols. We compared the pattern of weakness and electrophysiological abnormalities in 39 patients with a lower motoneuron syndrome and a positive response to intravenous immunoglobulins. All patients underwent an extensive standardized electrophysiological examination. Electrophysiological evidence of demyelination was found more often in the nerves of the arms and was distributed randomly over lower arm, upper arm and shoulder segments. Electrophysiological evidence of axonal loss presented more frequently in longer nerves, occurring most often in the leg nerves. For the arm nerves, it is possible that the length dependence of axonal loss is due to the random distribution of demyelinating lesions that lead to axonal degeneration. Weakness was associated with features of demyelination and axonal loss in the nerves of the arm, and with features of axonal loss in leg nerves. However, a substantial number (approximately one-third) of electrophysiological abnormalities were found in nerves innervating non-weakened muscles. These results imply that in MMN, conduction block is most likely to be found in long arm nerves innervating weakened muscles, but if conduction block cannot be detected in these nerves, the electrophysiological examination should be extended to other arm nerves including those innervating non-weakened muscles. |
| Databáze: | OpenAIRE |
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