Muscle membrane polarisation after provocative tests, and after cooling: the normal CMAP changes to be expected.

Détails

ID Serval
serval:BIB_050E76CAF73F
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Muscle membrane polarisation after provocative tests, and after cooling: the normal CMAP changes to be expected.
Périodique
Clinical Neurophysiology
Auteur(s)
Kuntzer T., Michel P.
ISSN
1388-2457
Statut éditorial
Publié
Date de publication
2004
Peer-reviewed
Oui
Volume
115
Numéro
6
Pages
1457-1463
Langue
anglais
Résumé
OBJECTIVE: To know the range of changes of compound muscle action potentials (CMAPs) in the muscles innervated by the ulnar nerve after diverse provocative tests, 14 healthy patients were studied with the same protocol. METHODS: CMAPs were measured at rest, just after a short exercise test (SET), during short 5 and 10c/s repetitive nerve stimulation (RNS) trains, at approximately 32 and approximately 20 degrees C. RESULTS: At 32 degrees C, the SET induced a significant but transient enlargement of the CMAPs (amplitude increased by 8.3%, duration decreased by 9%) that was only partially reproduced by RNS trains, except for a significant shortening of the CMAPs at 10c/s. At 20 degrees C without exercise, CMAPs increased significantly by approximately 30% in amplitude, duration and area, and after the SET the inverse of what has been seen at 32 degrees C was observed (amplitude decreased by 1.7% and duration increased by 9%). RNS at 20 degrees C produced a marked interpatient heterogeneity except for a significant shortening of the CMAPs at 10c/s. In one pure autonomic failure patient, the infusion of norepinephrine induced potentiation of the responses at rest and a decrease in the expected changes after provocative tests. CONCLUSIONS: CMAP amplitude and duration are significantly modified just after the SET at 32 degrees C, at rest at 20 degrees C and after RNS at 10c/s but not at 5c/s. Although providing indirect evidence, these findings indicate that provocative tests make the muscle membrane hyperexcitable by the way of a direct influence on the electrical events and by an indirect local catecholamine spillover.
Mots-clé
Action Potentials/physiology, Adult, Autonomic Nervous System Diseases/physiopathology, Cell Membrane/physiology, Cold Temperature, Electric Stimulation, Electromyography, Exercise/physiology, Female, Humans, Male, Middle Aged, Muscle, Skeletal/innervation, Ulnar Nerve/physiology
Pubmed
Web of science
Création de la notice
25/01/2008 13:43
Dernière modification de la notice
20/08/2019 13:26
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