Format

Send to

Choose Destination
Neuromuscul Disord. 2018 Mar;28(3):238-245. doi: 10.1016/j.nmd.2017.11.017. Epub 2017 Dec 12.

Specific muscle strength is reduced in facioscapulohumeral dystrophy: An MRI based musculoskeletal analysis.

Author information

1
Orthopaedic Research Laboratory, Radboud Institute for Health Sciences, Radboud university medical center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: mamarra@outlook.com.
2
Department of Radiology and Nuclear Medicine, Radboud university medical center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
3
Department of Neurology, Radboud university medical center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
4
Orthopaedic Research Laboratory, Radboud Institute for Health Sciences, Radboud university medical center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands; Department of Biomechanical Engineering, University of Twente, Postbus 217, 7500 AE Enschede, The Netherlands.

Abstract

The aim was to test whether strength per unit of muscle area (specific muscle strength) is affected in facioscapulohumeral dystrophy (FSHD) patients, as compared to healthy controls. Ten patients and ten healthy volunteers underwent an MRI examination and maximum voluntary isometric contraction measurements (MVICs) of the quadriceps muscles. Contractile muscle volume, as obtained from the MR images, was combined with the MVICs to calculate the physiological cross-sectional area (PCSA) and muscle strength using a musculoskeletal model. Subsequently, specific strength was calculated for each subject as muscle strength divided by total PCSA. FSHD patients had a reduced quadriceps muscle strength (median(1st quartile-3rd quartile): 2011 (905.4-2775) N vs. 5510 (4727-8321) N, p <0.001) and total PCSA (83.6 (62.3-124.8) cm2vs. 140.1(97.1-189.9) cm2, p = 0.015) compared to healthy controls. Furthermore, the specific strength of the quadriceps was significantly lower in patients compared to healthy controls (20.9 (14.7-24.0) N/cm2vs. 41.9 (38.3-49.0) N/cm2, p <0.001). Thus, even when correcting for atrophy and fatty infiltration, patients with FSHD generated less force per unit area of residual muscle tissue than healthy controls. Possible explanations include impaired force propagation due to fatty infiltration, reduced intrinsic force-generating capacity of the muscle fibers, or mitochondrial abnormalities leading to impaired energy metabolism.

KEYWORDS:

Facioscapulohumeral muscular dystrophy; Intrinsic weakness; Musculoskeletal modeling; Quantitative MRI; Specific strength

PMID:
29395674
DOI:
10.1016/j.nmd.2017.11.017

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center