Feasibility, safety, and efficacy of 12-week side-to-side vibration therapy in children and adolescents with congenital myopathy in New Zealand.

This pilot study explored the feasibility and effectiveness of vibration therapy (VT) on muscle and bone health, motor performance, and respiratory function in patients with congenital myopathy (CM). Eleven participants with CM (11.5 ± 2.8 years) underwent 12 weeks of side-alternating VT at 20 Hz for nine minutes per session, four days a week. VT was preceded by a 12-week control period. Assessments included dual-energy X-ray absorptiometry scans, 6-minute walk and 10-meter run tests, muscle function and motor performance assessment, dynamometry, and pulmonary function. VT was well-tolerated, with occasional mild itchiness reported. The median compliance level with VT treatment was 75%. 12 weeks of VT improved the total score of motor function performance by 2.4 units (p=0.006) and velocity rise maximum of the chair rising test by 0.11 m/s (p=0.029). VT was shown to be feasible, safe, and associated with improving motor function performance. Our findings support further exploration of VT's potential health benefits to patients with CM in larger studies involving a longer intervention period.

Exercise Cardiac Magnetic Resonance Imaging in Boys With Duchenne Muscular Dystrophy Without Cardiac Disease.

BACKGROUND: Duchenne muscular dystrophy is caused by mutations in the DMD gene, resulting in cardiomyopathy in all affected children by 18 years. Although cardiomyopathy is now the leading cause of mortality in these children, there is ongoing debate regarding timely diagnosis, secondary prevention, and treatment of this condition. The purpose of this study was to use exercise cardiac magnetic resonance imaging in asymptomatic young boys with Duchenne muscular dystrophy to describe their heart function and compare this with healthy controls. METHODS: We studied 11 boys with Duchenne muscular dystrophy aged 8.6 to 13.9 years and 11 healthy age- and sex-matched controls. RESULTS: Compared with the controls, boys with Duchenne muscular dystrophy had lower ejection fraction at rest (57% versus 63%; P = 0.004). During submaximal exercise, they reached similar peak tachycardia but increased their heart rate and cardiac output only half as much as controls (P = 0.003 and P = 0.014, respectively). End-systolic volume remained higher in boys with Duchenne muscular dystrophy both at rest and during exercise. When transthoracic echocardiography was compared with cardiac magnetic resonance imaging, 45% of the echocardiograms had suboptimal or poor views in the Duchenne muscular dystrophy group. CONCLUSIONS: Boys with Duchenne muscular dystrophy had abnormalities in left ventricular systolic function that were exaggerated by exercise stress. Exercise cardiac magnetic resonance imaging is feasible in a select population of children with Duchenne muscular dystrophy, and it has the potential to unmask early signs of cardiomyopathy.

Imaging the heart to detect cardiomyopathy in Duchenne muscular dystrophy: A review.

Duchenne Muscular Dystrophy is the most common paediatric neuromuscular disorder. Mutations in the DMD gene on the X-chromosome result in progressive skeletal muscle weakness as the main clinical manifestation. However, cardiac muscle is also affected, with cardiomyopathy becoming an increasingly recognised cause of morbidity, and now the leading cause of mortality in this group. The diagnosis of cardiomyopathy has often been made late due to technical limitations in transthoracic echocardiograms and delayed symptomatology in less mobile patients. Increasingly, evidence supports earlier pharmacological intervention in cardiomyopathy to improve outcomes. However, the optimal timing of initiation remains uncertain, and the benefits of prophylactic therapy are unproven. Current treatment guidelines suggest initiation of therapy once cardiac dysfunction is detected. This review focuses on new and evolving techniques for earlier detection of Duchenne muscular dystrophy-associated cardiomyopathy. Transthoracic echocardiography or cardiac magnetic resonance imaging performed under physiological stress (dobutamine or exercise), can unmask early cardiac dysfunction. Cardiac magnetic resonance imaging can define cardiac function with greater accuracy and reliability than an echocardiogram, and is not limited by body habitus. Improved imaging techniques, used in a timely fashion, offer the potential for early detection of cardiomyopathy and improved long-term outcomes.