Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004093 (asthenia)
 2,650 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Multifocal motor neuropathy with persistent conduction block (MMN) is a rare clinical entity, mimicking motor neuron disease (MND). In order to research which are the most frequent nerves and segments where conduction block (CB) can be identified, we reviewed the clinical and neurophysiological data of nine patients with MMN who were studied and followed by the authors. Weakness and muscle atrophy of the dominant hand was the most frequent presentation. Lower limbs were involved later in the disease evolution. The ulnar and median nerves were the most affected nerves. They had conduction blocks mostly at the forearm and at Erb's point-elbow (or above elbow) segments. Both common peroneal and tibial nerves were frequently affected at their distal segments, but proximal segments were also probably involved. The presence of anti-GM1 antibodies was variable, and their determination was not essential for the diagnosis of MMN. Eight patients given IV immunoglobulin therapy had no disease progression. One patient was responsive to corticosteroids. The CB identification in our patients allowed us to clearly distinguish MMN from MND. The good prognosis and need for management with IV immunoglobulin, support the crucial role of a careful neurophysiological study to diagnose this clinical entity.
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PMID:Multifocal motor neuropathy mimicking motor neuron disease: nine cases. 1054 11

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.
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PMID:Demyelination and axonal loss in multifocal motor neuropathy: distribution and relation to weakness. 1247 6