Estimating motor unit numbers from a CMAP scan: Repeatability study on three muscles at 15 centres

D. M. Sørensen, H. Bostock, A. Abrahao, A. Alaamel, H. C. Alaydin, M. Ballegaard, E. Boran, B. Cengiz, M. de Carvalho, Dunker, A. Fuglsang-Frederiksen, C. C. Graffe, K. E. Jones, M. Kallio, S. Kalra, C. Krarup, T. Krøigård, R. Liguori, T. Lupescu, S. MaitlandJ. M. Matamala, M. Moldovan, J. Moreno-Roco, K. B. Nilsen, L. Phung, M. O. Santos, A. C. Themistocleous, H. Uysal, V. Vacchiano, R. G. Whittaker, L. Zinman, H. Tankisi*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

12 Citations (Scopus)

Abstract

Objective: To assess the repeatability and suitability for multicentre studies of MScanFit motor unit number estimation (MUNE), which involves modelling compound muscle action potential (CMAP) scans. Methods: Fifteen groups in 9 countries recorded CMAP scans twice, 1–2 weeks apart in healthy subjects from abductor pollicis brevis (APB), abductor digiti minimi (ADM) and tibialis anterior (TA) muscles. The original MScanFit program (MScanFit-1) was compared with a revised version (MScanFit-2), designed to accommodate different muscles and recording conditions by setting the minimal motor unit size as a function of maximum CMAP. Results: Complete sets of 6 recordings were obtained from 148 subjects. CMAP amplitudes differed significantly between centres for all muscles, and the same was true for MScanFit-1 MUNE. With MScanFit-2, MUNE differed less between centres but remained significantly different for APB. Coefficients of variation between repeats were 18.0% for ADM, 16.8% for APB, and 12.1% for TA. Conclusions: It is recommended for multicentre studies to use MScanFit-2 for analysis. TA provided the least variable MUNE values between subjects and the most repeatable within subjects. Significance: MScanFit was primarily devised to model the discontinuities in CMAP scans in patients and is less suitable for healthy subjects with smooth scans.

Original languageEnglish
Book seriesClinical Neurophysiology
Volume151
Pages (from-to)92-99
Number of pages8
ISSN1388-2457
DOIs
Publication statusPublished - 2023

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© 2023

Keywords

  • CMAP Scan
  • Motor unit number estimation
  • MScanFit
  • MUNE
  • Repeatability

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