Muscle Velocity Recovery Cycles to Examine Muscle Membrane Properties.

Witt, Agnes; Bostock, Hugh; Z'Graggen, Werner J.; Tan, S Veronica; Kristensen, Alexander Gramm; Kristensen, Rikke Søgaard; Larsen, Lotte Hardbo; Zeppelin, Zennia; Tankisi, Hatice (2020). Muscle Velocity Recovery Cycles to Examine Muscle Membrane Properties. Journal of visualized experiments(156) MYJoVE Corporation 10.3791/60788

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Although conventional nerve conduction studies (NCS) and electromyography (EMG) are suitable for the diagnosis of neuromuscular disorders, they provide limited information about muscle fiber membrane properties and underlying disease mechanisms. Muscle velocity recovery cycles (MVRCs) illustrate how the velocity of a muscle action potential depends on the time after a preceding action potential. MVRCs are closely related to changes in membrane potential that follow an action potential, thereby providing information about muscle fiber membrane properties. MVRCs may be recorded quickly and easily by direct stimulation and recording from multi-fiber bundles in vivo. MVRCs have been helpful in understanding disease mechanisms in several neuromuscular disorders. Studies in patients with channelopathies have demonstrated the different effects of specific ion channel mutations on muscle excitability. MVRCs have been previously tested in patients with neurogenic muscles. In this prior study, muscle relative refraction period (MRRP) was prolonged, and early supernormality (ESN) and late supernormality (LSN) were reduced in patients compared to healthy controls. Thereby, MVRCs can provide in vivo evidence of membrane depolarization in intact human muscle fibers that underlie their reduced excitability. The protocol presented here describes how to record MVRCs and analyze the recordings. MVRCs can serve as a fast, simple, and useful method for revealing disease mechanisms across a broad range of neuromuscular disorders.

Item Type:	Journal Article (Further Contribution)
Division/Institute:	04 Faculty of Medicine > Department of Head Organs and Neurology (DKNS) > Clinic of Neurosurgery 04 Faculty of Medicine > Department of Head Organs and Neurology (DKNS) > Clinic of Neurology
UniBE Contributor:	Z'Graggen, Werner Josef
Subjects:	600 Technology > 610 Medicine & health
ISSN:	1940-087X
Publisher:	MYJoVE Corporation
Language:	English
Submitter:	Nicole Söll
Date Deposited:	07 Jul 2020 14:59
Last Modified:	05 Dec 2022 15:39
Publisher DOI:	10.3791/60788
PubMed ID:	32150167
URI:	https://boris.unibe.ch/id/eprint/145022