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Motor unit number index: Guidelines for recording signals and their analysis
Author(s) -
Nandedkar Sanjeev D.,
Barkhaus Paul E.,
Stålberg Erik V.,
Neuwirth Christoph,
Weber Markus
Publication year - 2018
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.26099
Subject(s) - electromyography , amyotrophic lateral sclerosis , motor unit , compound muscle action potential , physical medicine and rehabilitation , duration (music) , motor unit recruitment , medicine , biomedical engineering , electrophysiology , anatomy , physics , disease , acoustics
ABSTRACT Introduction : This study proposes guidelines for motor unit number index (MUNIX) recording and analysis. Methods : MUNIX was measured in control participants and in patients with amyotrophic lateral sclerosis. Changes in MUNIX values due to E1 electrode position, number of surface electromyography interference pattern (SIP) epochs, SIP epoch duration, force of contraction, and outlier data points were investigated. Results: MUNIX depends on optimized compound muscle action potential (CMAP) amplitude. Individual muscles showed variations when the number of epochs was low or when the SIP duration was short. Longer SIP duration allowed better recognition of artifacts. MUNIX results were affected by SIP values at all force levels but was more affected when SIP area was low. Discussion: We recommend changing the E1 electrode position to maximize CMAP amplitude. Twenty or more SIP signals of 500‐ms duration should be recorded by using force levels ranging from slight to maximum. Traces should be reviewed to identify and exclude signals with tremor or solitary spikes. Muscle Nerve 58 : 374–380, 2018