A major disadvantage of MR elastography is the high costs of this technology. Ultrasound elastography, a novel development for assessing tissue stiffness, is considerably more affordable. This technology demonstrates a high applicability for the assessment of muscular tissues located within a few centimetres of the skin (85). While a skilled physician with excellent palpatory skills may be able to detect and assess regions of increased tissue stiffness as well, this technology could be used to document the progression of muscular fibrosis (e.g. when Inhibitors,research,lifescience,medical conducted once per year) in a quantifiable manner (86). However, for assessment of the important fibrotic changes in bronchial

and pericardic tissues in DMD patients, ultrasound elastography is not sufficient. For these purposes, MR elastography Inhibitors,research,lifescience,medical seems more suitable. Myography The development of passive tissue stiffness can also be assessed by biomechanical measurement of the tissue response to a calibrated indentation. Several portable tools are available that claim to measure muscle viscoelastic properties by simulated palpation through the skin (87). The newly developed MyotonPRO seems most promising, as it contains a highly sensitive triaxial BGB324 order accelerometer Inhibitors,research,lifescience,medical and its

basic technology has been successfully tested in conditions such as Parkinson’s disease and stroke (88, 89). While a previous model (Myoton-2) had been examined as a reliable tool for measuring muscle viscoelastic stiffness in healthy adults (90), the reliability of this Inhibitors,research,lifescience,medical improved version still needs to be properly examined, particularly with a wider range of patients and tissue properties, including DMD patients with different disease severities. Only tissues close to the skin can be examined; deeper connective tissues such as from deeper muscles or around the

lungs and heart cannot be reached with this Inhibitors,research,lifescience,medical tool. Advantages of this technology include its portability, affordability and ease of application. Conclusions While muscular dystrophies have mostly been approached as a dysfunction of skeletal myofibres, the accompanying changes in the connective tissue deserve specific interest as well. An increased understanding of the molecular dynamics underlying inflammation, myofibroblast proliferation, many tissue contracture and fibrosis will help in the development of future antifibrotic therapy approaches. A proactive early intervention is recommended, with particular emphasis being given to the pulmonary and pericardial connective tissues. In order to monitor the fibrotic tissue changes, the investigation and further development of appropriate assessment tools seems essential. Acknowledgements We thank Dr. Reinhardt Rüdel for his active involvement in the generation of this review und Dr. Heike Jäger for discussions. Frank Lehmann-Horn is endowed Senior Research Professor for Neurosciences of the non-profit Hertie Foundation.