INTRODUCTION: In this study we aimed to clarify whether muscle ultrasound (US) of the forearm can be used to differentiate between patients with sporadic inclusion body myositis (s-IBM) and those with s-IBM-mimicking diseases. METHODS: We compared the echo intensity (EI) of the flexor digitorum profundus (FDP) muscle and the flexor carpi ulnaris (FCU) muscles in patients with s-IBM (n = 6), polymyositis/dermatomyositis (PM/DM; n = 6), and amyotrophic lateral sclerosis (ALS; n = 6). RESULTS: We identified EI abnormalities in 100% of patients with s-IBM, 33% of those with PM/DM, and 33% of those with ALS. An "FDP-FCU echogenicity contrast," a US pattern involving a higher EI in the FDP than in the FCU, was observed in all patients with s-IBM, but in none of those with PM/DM or ALS. CONCLUSIONS: FDP-FCU echogenicity contrast in muscle US is a sensitive diagnostic indicator of s-IBM.
INTRODUCTION: In this study we aimed to clarify whether muscle ultrasound (US) of the forearm can be used to differentiate between patients with sporadic inclusion body myositis (s-IBM) and those with s-IBM-mimicking diseases. METHODS: We compared the echo intensity (EI) of the flexor digitorum profundus (FDP) muscle and the flexor carpi ulnaris (FCU) muscles in patients with s-IBM (n = 6), polymyositis/dermatomyositis (PM/DM; n = 6), and amyotrophic lateral sclerosis (ALS; n = 6). RESULTS: We identified EI abnormalities in 100% of patients with s-IBM, 33% of those with PM/DM, and 33% of those with ALS. An "FDP-FCU echogenicity contrast," a US pattern involving a higher EI in the FDP than in the FCU, was observed in all patients with s-IBM, but in none of those with PM/DM or ALS. CONCLUSIONS: FDP-FCU echogenicity contrast in muscle US is a sensitive diagnostic indicator of s-IBM.
Authors: Kristofoor E Leeuwenberg; Nens van Alfen; Lisa Christopher-Stine; Julie J Paik; Eleni Tiniakou; Christopher Mecoli; Jonne Doorduin; Christiaan G J Saris; Jemima Albayda Journal: Muscle Nerve Date: 2020-04-11 Impact factor: 3.852