Muscular Dystrophy Basics
Richard M. Lovering, Neil C. Porter, and Robert J. Bloch coalesce information from over 150 sources to create this succinct guide on the genetic basis and treatment for multiple types of muscular dystrophy (MD). In the past, diagnosis of MDs were largely dependent on phenotype. Today, we have genetic testing and better knowledge about the genetic basis for many muscular disorders, which has improved diagnostic accuracy but has not advanced treatment or management to the same magnitude. Even with gene therapy cures presented as an optimistic outlook for the future, MD patients will still require physical therapy to optimize movement and functionality. Different types of MD may respond best to different treatment approaches, which is why it is essential for physical therapists treating MD patients to be knowledgeable about the pathologic mechanisms involved.
Dystrophin, a protein that helps bind sarcolemma to muscle fibers, is regarded as a key player when it comes to muscular dystrophies. MDs are often a result of a dystrophin dysfunction, such as not repairing properly or lacking in the first place. Lovering et al. also briefly mention integrin and missing or truncated proteins as playing a role in the development of some MDs but these are not elaborated on nearly as thoroughly as dystrophin. The use of utrophin, stem cell therapy, and myoblast transfer are all being explored as potential treatments for MD, but delivering the dystrophin gene to all the muscles of the body presents some serious challenges. In order for any treatment to be effective, it must carry the enormous dystrophin gene, reach the center of the dystrophin-associated protein complex (DAPC), and reach every muscle, including non-skeletal muscle. On top of this, there is the risk that these treatments could stimulate an unwanted immune response.
As there is presently no cure for muscular dystrophy, current treatments focus on improving quality of life and slowing the progression of the disease. Also, most MD treatments are focused on caring for patients with Duchenne MD, as it is the most common and most aggressive type. Typical pharmacological care includes the prescription of the anti-inflammatories prednisone or deflazacort or the antibiotic gentamicin. The typical physical therapy (PT) goals for MD include prevention of joint contracture or spinal deformity progression, prolonging ambulation, and maintaining functionality levels. The methods used often include development of a safe exercise program (mostly light to moderate resistive exercise, like hydrotherapy, while avoiding exhaustive or maximal effort exercise), evaluating the home for safety, monitoring for progressive scoliosis, prescribing assistive devices (such as night splints), and providing family and caregiver education on passive range of motion exercises, transfers, and repositioning.
As this article is 16 years old, I would love to know if there have been any advancements in MD treatment since it’s publishing date. Regardless, I still found it incredibly informative and I’m glad I took time out of my week to thoroughly read and understand the topic. The recommendations for light and steady PT treatment, rather than maximum effort approaches, reminds me of the currently developing guidance for treatment of patients affected by COVID-19, who may be experiencing post-exertional malaise. Many PTs enter the field with a sports related background, where the mentality to “push harder” is revered. When treating patients with certain diagnoses, it’s important to keep in mind that this can be harmful and counterproductive, while slow and steady may be more beneficial.
https://academic.oup.com/ptj/article/85/12/1372/2805113?login=true