Motor unit potentials with satellites in dystrophinopathies.

The objective of this study was to analyze the motor unit potentials (MUPs) with satellite components i.e., delayed by at least 2ms baseline from the main component, in the dystrophinopathies. The parameters of the MUPs recorded from the biceps brachii muscle in the Duchenne and Becker Muscle Dystrophy (DMD, BMD) were analyzed. The origin of the MUP satellite components was studied using a computer simulation. As compared with normal potentials, both the main and the satellite MUP components are smaller in size, while the main components are more irregular. The computer simulation allows the range of muscle fiber diameters to be determined, and suggests that the variability characterizing diameters within the motor unit is responsible for generating the delayed, satellite components, via the linear relationship between the fiber diameter and the conduction velocity of the action potential. The enhanced understanding of the origin of the MUP satellite components augments the knowledge about the relationship between muscle morphology and bioelectrical activity. The indirect evaluation of the range of muscle fiber diameters by means of a computer simulation may provide a new quantitative morphological data available from the EMG. Copyright © 2012 Elsevier Ltd. All rights reserved.

Citation

Ewa Zalewska, Elzbieta Szmidt-Salkowska, Katarzyna Rowinska-Marcinska, Anna Kaminska, Irena Hausmanowa-Petrusewicz. Motor unit potentials with satellites in dystrophinopathies. Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology. 2013 Jun;23(3):580-6

PMID: 23369874

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