A two-site collaborative study of electrical impedance myography for evaluation of disease progression in murine Duchenne muscular dystrophy models

Accessibility to outcome measures that reliably assess disease pathology in preclinical studies are vital, especially for rare disorders such as Duchenne muscular dystrophy (DMD). The non-invasive technique of electrical impedance myography (EIM) has shown potential as an outcome measure in patients and mouse models of neuromuscular disorders. However, these preclinical observations have been limited to a single site. Here, we performed a longitudinal, parallel two-site study to assess the potential of EIM as an outcome measure by using two DMD mouse models - mdx mice on a C57BL/10ScSn/J or DBA/2J genetic background - differing in disease severity, and being hypertrophic and atrophic, respectively, over a ten-month period, in which mice were evaluated monthly. We found that longitudinally acquired phase values were the most reliable, with relatively minor differences between study sites. Histopathology, assessed at 8, 12, 28, or 52 weeks of age correlated well with EIM phase values in both models. Our findings highlight the applicability of EIM as a robust, preclinical outcome measure for DMD.