Jump to ContentJump to Main Navigation
Laboratory Reference for Clinical Neurophysiology$
Users without a subscription are not able to see the full content.

Jay A. Liveson and Dong M. Ma

Print publication date: 1999

Print ISBN-13: 9780195129243

Published to Oxford Scholarship Online: March 2012

DOI: 10.1093/acprof:oso/9780195129243.001.0001

Show Summary Details
Page of

PRINTED FROM OXFORD SCHOLARSHIP ONLINE (www.oxfordscholarship.com). (c) Copyright Oxford University Press, 2019. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a monograph in OSO for personal use (for details see www.oxfordscholarship.com/page/privacy-policy).date: 15 February 2019

Motor Unit Potential Studies

Motor Unit Potential Studies

Chapter:
(p.408) Chapter 23 Motor Unit Potential Studies
Source:
Laboratory Reference for Clinical Neurophysiology
Author(s):

Jay A. Liveson

Dong M. Ma

Publisher:
Oxford University Press
DOI:10.1093/acprof:oso/9780195129243.003.0023

The discharge of an anterior horn cell causes an action potential to travel down its axon, producing an almost synchronous depolarization of the muscle fibers it innervates. This physiologic unit is the motor unit and the summated potential generated is the motor unit potential (MUP) or motor unit action potential. The first section of this chapter addresses the values of MUPs available in the literature. The values are classified by the type of needle used (concentric versus monopolar), then by the age of the subject. Values of specific muscles are given for the duration, amplitude, and percentage of polyphasia, which reflects configuration. In general, the MUPs in myopathies are of short duration, low amplitude, and possibly polyphasic configuration. This pattern is thought to reflect loss of muscle fibers. In contrast, in neuropathic processes, the MUPs are of long duration. This is thought to result from increased temporal dispersion in terminal nerve fibers.

Keywords:   anterior horn cell, depolarization, motor unit potential, motor unit action potential, polyphasia, temporal dispersion, myopathies

Oxford Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.

Please, subscribe or login to access full text content.

If you think you should have access to this title, please contact your librarian.

To troubleshoot, please check our FAQs , and if you can't find the answer there, please contact us .