Muscle ultrasound is a responsive biomarker in facioscapulohumeral dystrophy
Rianne J.M. Goselink, Tim H.A. Schreuder, Karlien Mul, Nicol C. Voermans, Corrie E. Erasmus, Baziel G.M. van Engelen, Nens van Alfen
Abstract
<h3>Objective</h3> With drug trials starting soon, responsive, relevant, and patient-friendly biomarkers are highly needed in facioscapulohumeral dystrophy (FSHD). Our objective was to assess muscle ultrasound (MUS) as an imaging biomarker in patients with FSHD. <h3>Methods</h3> One-year observational, longitudinal study of both quantitative and qualitative MUS changes in FSHD. <h3>Results</h3> Twenty-two patients with symptomatic FSHD1 underwent a clinical examination and MUS at baseline and after 1-year follow-up. The qualitative MUS sum score increased from 18.59 to 20.32 (<i>p</i> = 0.005) and the quantitative MUS sum <i>z</i> scores increased from 19.96 to 24.72 (<i>p</i> = 0.003). The clinical scores did not change over 1 year. Muscle echogenicity correlated with the FSHD clinical score at baseline (<i>r</i> = 0.61, <i>p</i> = 0.002). <h3>Conclusions</h3> MUS shows a significant increase in echogenicity in FSHD over 1 year. Both quantitative and qualitative MUS correlate cross-sectionally with clinical severity in FSHD and identify structural muscle changes in a clinically stable group of patients. MUS thus seems a potentially responsive biomarker that could be standardized between centers. We recommend its use in therapeutic trials. <h3>Classification of evidence</h3> This study provides Class I evidence that in patents with FSHD1, MUS findings correlate with baseline FSHD clinical scores.