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Updated: Aug 29, 2026

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Published on: February 19, 2020
Motor excitability in myopathy
Joachim Liepert1, Benedikt G H Schoser, Cornelius Weiller
1Department of Neurology, University of Hamburg, University Hospital Eppendorf, Martini Strasse 52, D-20246 Hamburg, Germany. liepert@uke.uni-hamburg.de
Objective:
To explore whether patients with myopathy present changes in motoneuronal excitability.
Methods:
Patients with well-defined myopathies were studied with single and paired pulse transcranial magnetic stimulations and electrical nerve stimulations to explore neuronal motor excitability. Motor-evoked potentials were recorded from the clinically unaffected first dorsal interosseous muscle (n=10) and the paretic deltoid muscle (n=8).
Results:
Compared to an age-matched healthy control group, myopathic patients showed a reduction of intracortical inhibition, enhancements of alpha-motoneuron excitability and increased amplitudes of motor-evoked potentials during target muscle contraction. These alterations were present in clinically affected and clinically unaffected muscles.
Conclusion:
In myopathy, nervous system excitability may be altered, presenting as a motor disinhibition on cortical and subcortical levels.
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