CORTICAL EXCITABILITY DIFFERENCES IN HAND MUSCLES FOLLOW A SPLIT-HAND PATTERN IN HEALTHY CONTROLS

Introduction: Sensitive, non-invasive techniques are needed that can provide biomarkers of disease status and the effects of therapy in muscular dystrophy. Methods: We evaluated electrical impedance myography (EIM) to serve in this role by studying 2-month-old and 18-month-old mdx and wild-type (WT) animals (10 animals in each of 4 groups). Results: Marked differences were observed in EIM values between mdx and WT animals; the differences were more pronounced between the older age groups (e.g., reactance of 92.6 +/- 4.3 omega for mdx animals vs. 130 +/- 4.1 omega for WT animals, P < 0.001). In addition, in vivo EIM parameters correlated significantly with the extent of connective tissue deposition in the mdx animals. Conclusions: EIM has the potential to serve as a valuable non-invasive method for evaluating muscular dystrophy. It can be a useful biomarker to assist with therapeutic testing in both pre-clinical and clinical studies. Muscle Nerve 49: 829-835, 2014