Mauro Lo Monaco1, Adele D'Amico2, Marco Luigetti1, Jean-François Desaphy3, Anna Modoni4. 1. Department of Geriatrics, Neurosciences & Orthopedics, Institute of Neurology, Catholic University of the Sacred Heart, Rome, Italy. 2. Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesù Hospital, Rome, Italy. 3. Section of Pharmacology, Department of Pharmacy & Drug Sciences, University of Bari - Aldo Moro, Bari, Italy. 4. Department of Geriatrics, Neurosciences & Orthopedics, Institute of Neurology, Catholic University of the Sacred Heart, Rome, Italy. Electronic address: amodoni@rm.unicatt.it.
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.
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.
Authors: C Altamura; G F Mangiatordi; O Nicolotti; D Sahbani; A Farinato; F Leonetti; M R Carratù; D Conte; J-F Desaphy; P Imbrici Journal: Br J Pharmacol Date: 2018-04-06 Impact factor: 8.739
Authors: P Imbrici; L Maggi; G F Mangiatordi; M M Dinardo; C Altamura; R Brugnoni; D Alberga; G Lauria Pinter; G Ricci; G Siciliano; R Micheli; G Annicchiarico; G Lattanzi; O Nicolotti; L Morandi; P Bernasconi; J-F Desaphy; R Mantegazza; D Conte Camerino Journal: J Physiol Date: 2015-07-14 Impact factor: 5.182