Quantitative Whole-Body MRI Biomarker Relation to Muscle Strength & Function in FSHD Patients

Topic:

Translational Research

Poster Number: P205

Author(s):

Mary Foltz, PhD, AMRA Medical AB, Per Widholm, MD, AMRA Medical, Markus Karlsson, PhD, AMRA Medical, Jonathan Pini, PhD, Peripheral Nervous System and Muscle Department, University Côte d’Azur, Angela Puma, MD, Peripheral Nervous System and Muscle Department, University Côte d’Azur, Luisa Villa, MD, Peripheral Nervous System and Muscle Department, University Côte d’Azur, Michele Cavalli, MD, Nice University Hospital, Andra Ezaru, MD, Peripheral Nervous System and Muscle Department, University Côte d’Azur, Guillaume Bassez, MD, Unité de Morphologie Neuromusculaire, Institut de Myologie Sorbonne University, Benjamin Marty, PhD, Unité de Morphologie Neuromusculaire, Institut de Myologie Sorbonne University, Teresinha Evangelista, MD, Institute of Myology, Romain Thomas, Centre de référence des maladies neuromusculaires Nord/Est/Ile-de-France, CHU Lille, Loïc Danjoux, MD, Centre de référence des maladies neuromusculaires Nord/Est/Ile-de-France, CHU Lille, Céline Tard, MD, Centre de référence des maladies neuromusculaires Nord/Est/Ile-de-France, CHU Lille, Sabrina Sacconi, MD, Peripheral Nervous System and Muscle Department, University Côte d’Azur

Background: FSHD has a heterogeneous disease onset pattern and slow progression, making assessment of change in patient function challenging in clinical trials. Quantitative whole-body MRI can identify fast progressing muscles and is used as biomarkers in clinical trials, but the relationship between these biomarkers and functional assessments have not fully established.
Aim: Explore relationship between functional assessments and MRI biomarkers in patients with FSHD.
Methods: 68 ambulatory FSHD-patients, from the CTRN FSHD (NCT04038138) France Natural History Study, were evaluated using quantitative whole-body MRI, quantitative muscle strength assessments, and 6-minute walk test (6MWT). Peak muscle strength from fixed muscle dynamometry (biceps brachii, triceps brachii, hamstrings, quadriceps, and anterior tibialis bilaterally) were correlated to total muscle volume (TMV), lean muscle volume (LMV), muscle fat fraction (MFF), and muscle fat infiltration (MFI), quantified using AMRA Researcher. 6MWT was correlated to composites measurements of all leg muscles.
Results: Patients were, mean (SD), 50 (13) years old, 66% male, with a FSHD-CSS of 5.2 (2.0). Muscle strength was 14.9-kg (7.6), 11.2-kg (4.9), 12.5-kg (8.6), 26.2-kg (14.3), and 12.3-kg (8.6) for biceps, triceps, hamstrings, quadriceps, and anterior tibialis, respectively. In arm muscles (biceps, triceps), correlation between strength and muscle volume were strong in TMV (0.68, 0.61) and LMV (0.75, 0.65), moderate in MFF (-0.53, -0.45) and MFI (-0.58, -0.45). For leg muscles (hamstrings, quadriceps), correlations between strength and muscle volume were moderate for hamstring TMV (0.43) and for quadriceps MFF/MFI (-0.59, -0.6), remaining muscle correlations were strong. Correlations between 6MWT and composite scores were moderate for LMV (0.53), MFF (-0.57), and MFI (-0.54).
Conclusion: Muscle volume and fat content, per quantitative MRI, are strongly correlated to muscle strength in individual muscles in patients with FSHD. Correlation to more complex functional tasks can be achieved by combining multiple muscles into composite measurements.