Non-invasive imaging of single human motor units.
Clin Neurophysiol
; 131(6): 1399-1406, 2020 06.
Article
em En
| MEDLINE
| ID: mdl-32122767
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.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Músculo Esquelético
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Imagem de Difusão por Ressonância Magnética
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Neurônios Motores
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article