Lookup NU author(s): Matt Birkbeck,
Dr Linda Heskamp,
Dr Ian Schofield,
Professor Andrew Blamire,
Professor Roger Whittaker
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Abstract: Objective: To determine the size, shape and distribution of single human motor units in-vivo in healthy controls of different ages. Methods: A novel diffusion-weighted magnetic resonance imaging (MRI) technique was used in combination with in-scanner electrical stimulation to quantify the shape, cross-sectional area, and dimensions of individual motor units in 10 healthy subjects. Results: Thirty-one discrete motor units were studied. The majority were elliptical or crescent shaped, but occasional split motor units were observed. The mean motor unit cross sectional area was 26.7 ± 11.2 mm2, the mean maximum dimension was 10.7 ± 3.3 mm, and the mean minimum dimension was 4.5 ± 1.2 mm. Subjects aged over 40 had significantly larger maximum dimensions than those below this age (p < 0.05). Conclusions: Motor unit MRI (MUMRI) is a novel technique capable of revealing the size, shape and position of multiple motor units in human muscles. It is reproducible, non-invasive, and sufficiently sensitive to detect physiologically relevant changes in motor unit morphology with age. Significance: To our knowledge, these results provide the first imaging assessment of human motor unit morphology. The technique shows promise both as a diagnostic tool and as a biomarker in longitudinal studies of disease progression.
Author(s): Birkbeck MG, Heskamp L, Schofield IS, Blamire AM, Whittaker RG
Publication type: Article
Publication status: Published
Journal: Clinical Neurophysiology
Print publication date: 01/06/2020
Online publication date: 21/02/2020
Acceptance date: 11/02/2020
Date deposited: 12/02/2020
ISSN (print): 1388-2457
ISSN (electronic): 1872-8952
Publisher: Elsevier Ireland Ltd.
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