Duchenne muscular dystrophy (DMD) is the most common childhood-onset form of muscular dystrophy affecting approximately 1 in 3500 male births worldwide. The disease is x-linked and is caused by mutations in the dystrophin gene, leading to disruption of the sarcolemma. The disease is usually recognized between the ages of 3 and 6 years. Boys carrying the mutation develop progressive muscle degeneration, resulting in muscle weakness and atrophy and leading to motor delays, loss of ambulation, failure of the muscles that support ventilation, and cardiomyopathy. Death usually occurs because of respiratory failure or cardiac compromise.
Several important developments have recently impacted the natural history of DMD. With multidisciplinary care, people with DMD can now survive into their 30s or even 40s. The adoption of steroid treatment has resulted in prolongation of ambulation from a mean of 10 years to 11 to 14 years in treated individuals (depending on the specific steroid regimen) and the Food and Drug Administration had recently granted full approval for deflazacort, the first glucocorticoid with a label indication for DMD. In addition, the field has benefited from recent advances in gene-targeted treatments and several dystrophin restoration therapies are in development. Two mutation-specific agents are now available, ataluren in Europe and eteplirsen in the Unites States.
With longer lives, a renewed sense of optimism as well as new challenges related to transition into adulthood have emerged. To address the evolving needs of DMD patients, the Center for Disease Control has supported the development of revised guidelines for DMD care (known as DMD Care Considerations). The DMD Care Considerations update the 2010 guidelines and were published in a set of three articles in Lancet Neurology in March 2018 (freely available online at https://www.cdc.gov/ncbddd/musculardystrophy/care-considerations.html).
Guideline Development Methodology
The DMD Care Considerations were developed by the DMD Care Considerations Working Group, a diverse expert panel that included several physiatrists and rehabilitation specialists. The group identified 11 topics and reviewed available evidence between 2014 and 2017. Few large-scale randomized controlled trials (RCTs) have been completed for DMD and most of the available RCTs are studies of corticosteroids. Therefore, for most of the topics under consideration, available evidence is based on natural history, cohort studies, and nonrandomized trials. To synthesize the scientific literature, the working group used the RAND/UCLA Appropriateness Method (https://www.rand.org/health/surveys_tools/appropriateness.html), a well-established formal mechanism for quality assessment and best practices-guideline development. Only assessments that were deemed both appropriate and necessary were recommended. These Care Considerations are therefore not traditionally evidence-based. However, they are based on systematic assessment of available data and reflect consensus views and practices of an expert panel.
What Has Changed in the New Guidelines?
The new DMD Care Considerations represent a fundamental shift in the care of people with DMD. Although in the past the main goal of DMD care was prolongation of survival, the focus has changed to optimization of quality of life, function, independence, and transition to adulthood. The DMD patients face new challenges related to education, employment, personal relationships, psychosocial issues, and intimacy. The new guidelines also emphasize the importance of the neuromuscular specialist as the lead physician who takes primary responsibility for the long-term multidisciplinary care of people with DMD, in collaboration with a diverse team of health care professionals.
What Has Not Changed in the New Guidelines?
The new DMD Care Considerations highlight once again the key role of rehabilitation across the lifespan to promote overall health, function, independence, and quality of life. Specific DMD-relevant rehabilitation recommendations are available online (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5869704/). Physical, occupational, and speech and language therapy are mainstays of DMD care. Recommendations include daily preventive home stretching programs and selected orthotic interventions, splinting, casting, positioning, and equipment. Submaximal aerobic activity (e.g., swimming and cycling) and avoidance of eccentric and high-resistance exercise are also recommended.
Why Is This Relevant for Physiatrists?
Physiatry has a critical role in contemporary DMD care. Physiatrists with subspecialty training in neuromuscular medicine may assume the role of lead neuromuscular specialist or work as consultants in the context of a DMD multidisciplinary clinic. Regardless, the importance of lifelong rehabilitation cannot be emphasized enough as it is paramount in assisting people with DMD to reach their full potential. As new disease-modifying treatments are developed, the need for comprehensive rehabilitation will continue to grow.