Electrical Impedance Myography and Ultrasound as Biomarkers of Duchenne Muscular Dystrophy
Condition: Duchenne Muscular Dystrophy
MeSH terms: Muscular Dystrophies; Muscular Dystrophy, Duchenne
Study type: Observational

Summary: 
      Researchers at Children's Hospital Boston Neurology Department invite children to participate
      in a new research study. Researchers are looking for boys ages 2 - 30 with Duchenne Muscular
      Dystrophy (DMD) and healthy boys ages 2 - 30 (without any nerve or muscle concerns) to serve
      as controls. The study is evaluating a new technique that will test nerve and muscle
      function. The testing is all pain free.

      Children participating in the study will come in for 10 visits over two years. Visits will
      take place every month at first, then less often for the remaining visits. The tests for the
      study itself take approximately 2hours. If participants are interested or would like to learn
      more about the study, please call Lavanya Madabusi at 617-919-3554 or
      Lavanya.Madabusi@childrens.harvard.edu. All inquiries will be kept strictly confidential.
    

Detailed description: 
      Characterized by progressive disability leading to death, Duchenne muscular dystrophy (DMD)
      remains one of the most common and devastating neuromuscular disorders of childhood. Although
      a variety of promising new treatment strategies are in development, outcome measures for
      clinical trials remain limited for the most part to a set of functional measures, such as the
      six-minute walk test. While clearly useful, such measures are impacted by unrelated factors,
      such as mood and effort, and have limited repeatability. To address this and other
      limitations, magnetic resonance imaging (MRI) is now being investigated as a surrogate
      measure. However, more easily applied, cost-effective, office-based surrogate measures that
      provide high repeatability and sensitivity while still correlating strongly to disease status
      would find wider use in Phase II and possibly in Phase III clinical trials in DMD.
      Quantitative ultrasound (QUS) and electrical impedance myography (EIM) are two techniques
      that could serve in this role. In QUS, muscle pathology (fibrosis and fatty infiltration) in
      DMD results in an increase in energy reflected back (backscatter) to the ultrasound. The
      amount of backscatter can be measured directly by analyzing the raw frequency-based acoustic
      data or indirectly by controlled processing of the gray-scale image. EIM, in contrast, relies
      upon the application of localized electrical current and measurement of the resulting surface
      voltages, but is similarly impacted by the fibrotic changes that develop as muscle disease
      progresses. Here, the investigators propose to evaluate and compare both methodologies
      simultaneously in a group of DMD patients and normal subjects in order to assess their
      ability to identify clinically meaningful alterations in muscle health over short intervals
      of time. As a final exploratory analysis, the investigators will also study the possibility
      of combining the two modalities. The results of this work will have broad application as they
      could be applied to a variety of neuromuscular conditions, including other muscular
      dystrophies. Thus, the hypothesis of this proposal is that both QUS and EIM can serve as
      convenient, non-invasive, clinically meaningful surrogate markers of disease progression in
      DMD that surpass the functional measures currently in use.
    

Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        This study will involve boys with DMD and healthy male controls.
      
Keywords: Duchenne Muscular Dystrophy; DMD; controls; EIM; QUS