In this study, the authors sought to understand the alteration in the anisotropic, or direction dependent, character of muscle as measured by electrical impedance myography (EIM) in 36 boys with DMD (27 healthy controls) and its potential to serve as a biomarker of disease status. Normalised reactance anisotropy, a direction-dependent measure of membrane charge storage capability, was significantly lower in the four muscles of DMD subjects as compared to controls (p<0.01). Normalised reactance anisotropy also decreased with increasing age in DMD subjects (r=-0.36, p=0.031), but not in healthy boys. These results support that loss of electrical anisotropy is a previously unrecognised feature of dystrophic muscle.
