RESUMEN
INTRODUCTION: Electrical impedance myography (EIM) is a noninvasive electrophysiological technique that characterizes muscle properties through bioimpedance. We compared EIM measurements to function, strength, and disease severity in a population with congenital muscular dystrophy (CMD). METHODS: Forty-one patients with CMD, either collagen 6 related disorders (COL6-RD; n = 21) or laminin α-2-related disorders (LAMA2-RD; n = 20), and 21 healthy pediatric controls underwent 2 yearly EIM exams. In the CMD cohorts, EIM was compared with functional and strength measurements. RESULTS: Both CMD cohorts exhibited change over time and had correlation with disease severity. The 50-kHZ phase correlated well with function and strength in the COL6-RD cohort but not in the LAMA2-RD cohort. DISCUSSION: EIM is a potentially useful measure in clinical studies with CMD because of its sensitivity to change over a 1-year period and correlation with disease severity. For COL6-RD, there were also functional and strength correlations. Muscle Nerve 57: 54-60, 2018.
Asunto(s)
Colágeno Tipo VI/genética , Impedancia Eléctrica , Laminina/genética , Distrofias Musculares/congénito , Distrofias Musculares/genética , Miografía/métodos , Adolescente , Niño , Preescolar , Estudios de Cohortes , Estudios Transversales , Femenino , Humanos , Masculino , Fuerza Muscular , Examen Neurológico/métodos , Carrera , Sensibilidad y Especificidad , Índice de Severidad de la EnfermedadRESUMEN
INTRODUCTION: Electrical impedance myography (EIM) is an emerging non-invasive, highly reproducible electrophysiological technique that objectively characterizes muscle structure and composition by measuring bioimpedance. We assessed the ability of EIM ability to discriminate 2 forms of congenital muscular dystrophy (CMD), laminin α2 (LAMA2)-deficient CMD and collagen VI-deficient (COL6) CMD, from a group of healthy children. We also investigated correlations between subcutaneous fat thickness and EIM parameters. METHODS: Twenty-eight children with LAMA2 CMD (n = 12) or COL6 (n = 16) CMD and 18 normal children underwent EIM testing. RESULTS: The EIM 50-kHz phase was decreased in LAMA2 and COL6 CMD when compared with controls (P < 0.001). Reactance, however, was decreased in COL6 but not LAMA2 CMD compared with controls (P < 0.001). CONCLUSIONS: Our findings suggest that EIM may be useful in discriminating CMD from controls and may serve as a useful biomarker to follow disease progression in clinical trials.