Abstract | OBJECTIVE: We aim to demonstrate the effect of mexiletine on the compound muscle action potential (CMAP) amplitude transitory depression (TD) in a cohort of patients with recessive myotonia congenita. METHODS: We evaluated 21 patients with recessive myotonia congenita referred to our institute from 1990 to 2013 and treated with mexiletine chlorhydrate. All patients underwent prolonged 3 Hz repetitive nerve stimulation (3 Hz-PLRS) before and after the beginning of treatment. RESULTS: We observed in all subjects a reduction of CMAP amplitude TD after the beginning of treatment. The mean value of the TD nadir before starting mexiletine treatment was -62.0% and reduced to -28.8% after the therapy was started (51.6% reduction, p<0.001). CONCLUSIONS: The 3 Hz-PLRS is configured as a neurophysiological test able to indirectly detect and quantify, through the measurement of TD, the clinical phenomenon of the transitory weakness that occurs in myotonic syndromes due to CLCN1 mutations. SIGNIFICANCE: This neurophysiological test might be considered a helpful tool to assess the effect of anti-myotonic drugs, as mexiletine, in recessive myotonia congenita.
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Authors | Mauro Lo Monaco, Adele D'Amico, Marco Luigetti, Jean-François Desaphy, Anna Modoni |
Journal | Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology
(Clin Neurophysiol)
Vol. 126
Issue 2
Pg. 399-403
(Feb 2015)
ISSN: 1872-8952 [Electronic] Netherlands |
PMID | 25065301
(Publication Type: Journal Article)
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Copyright | Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved. |
Chemical References |
- Voltage-Gated Sodium Channel Blockers
- Mexiletine
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Topics |
- Action Potentials
(drug effects, physiology)
- Adolescent
- Adult
- Aged
- Child
- Evoked Potentials, Motor
(drug effects, physiology)
- Female
- Humans
- Male
- Mexiletine
(pharmacology, therapeutic use)
- Middle Aged
- Myotonia Congenita
(diagnosis, drug therapy, physiopathology)
- Time Factors
- Treatment Outcome
- Voltage-Gated Sodium Channel Blockers
(pharmacology, therapeutic use)
- Young Adult
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