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Electrical impedance myography in duchenne muscular dystrophy and healthy controls: A multicenter study of reliability and validity
Author(s) -
Zaidman Craig M.,
Wang Lucy L.,
Connolly Anne M.,
Florence Julaine,
Wong Brenda L.,
Parsons Julie A.,
Apkon Susan,
Goyal Namita,
Williams Eugene,
Escolar Diana,
Rutkove Seward B.,
Bohorquez Jose L.
Publication year - 2015
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.24611
Subject(s) - electrical impedance myography , duchenne muscular dystrophy , intraclass correlation , medicine , physical medicine and rehabilitation , ambulatory , muscular dystrophy , physical therapy , reliability (semiconductor) , neuromuscular disease , intra rater reliability , cardiology , disease , psychometrics , confidence interval , power (physics) , physics , quantum mechanics , vasodilation , clinical psychology
: Electrical impedance myography (EIM) is a non‐invasive, painless, objective technique to quantify muscle pathology. Methods : We measured EIM in 8 arm and leg muscles in 61 boys with Duchenne muscular dystrophy (DMD) and 31 healthy boys, ages 3–12 years, at 5 centers. We determined the reliability of EIM and compared results in boys with DMD to controls and to 6‐minute walk distance (6MWD), North Star Ambulatory Assessment (NSAA), timed functional tests (TFTs), and strength (hand‐held dynamometry). Results : EIM was well tolerated and had good inter‐ and intrarater reliability (intraclass correlation coefficient 0.81–0.96). The averaged EIM phase value from all muscles was higher ( P < 0.001) in controls (10.45 ± 2.29) than boys with DMD (7.31 ± 2.23), and correlated ( P ≤ 0.001) with 6MWD ( r = 0.55), NSAA ( r = 0.66), TFTs ( r = –0.56), and strength ( r = 0.44). Conclusion : EIM is a reliable and valid measure of disease severity in DMD. Longitudinal studies comparing EIM with other assessments over time in DMD are warranted. Muscle Nerve 52: 592–597, 2015