Muscular dystrophy is a group of more than 30 distinct disorders that all impair the body’s normal process of building and restoring muscle, causing irreversible damage. As muscular dystrophy progresses, people experience varying levels of weakness and muscle-control problems. Some will be able to walk and move independently for the rest of their lives, but most patients will eventually need a wheelchair.
Muscular dystrophy affects children and adults. Because the disorder is so varied, it can be frustrating to get proper diagnosis and treatment. However, with proper care, it is possible for patients with muscular dystrophy to maintain a good quality of life. At Yale Medicine, our doctors not only treat your disease but also help you incorporate treatment into all aspects of your life.
What is muscular dystrophy?
Patients with muscular dystrophy have a genetic mutation that impairs the body’s process of creating proteins to build muscles and regenerate tissue. Over time, muscle fibers break down, leading to progressive muscle weakness and impaired coordination.
Muscular dystrophy is rare, and the most common muscular dystrophies (Duchenne and Becker), affect 14 out of every 100,000 males between ages 5 to 24.
What are the different types of muscular dystrophy?
There are nine broad categories of muscular dystrophies, and each is further broken down into different subtypes depending on severity, genetics, family history, age of onset, and other disease characteristics.
- Becker: This group of disorders is similar to Duchenne muscular dystrophy, but has a broad range of symptoms and disease progression. Patients are likely to start noticing muscle weakness as children or in their early teens. Some patients have rapidly progressing muscle weakness and will need to use a wheelchair during their teens and 20s. Other patients will be able to walk until their 30s or 40s. Survival rates vary, but many patients will live into their 50s and even 60s.
- Congenital: This group of muscular dystrophies is characterized by early onset of symptoms, which typically become apparent even before a child is 2 years old. People with congenital muscular dystrophy experience a wide array of symptoms. Children with congenital muscular dystrophy will experience progressive weakness in the skeletal muscles—those that connect to the bones and joints. This weakness might be mild in some children, while others may never learn to walk.
- Distal: Distal muscular dystrophy is a group of conditions associated with weakness in the distal muscles, or muscles in the lower legs and feet, forearms, and hands. Weakness might also progress to the muscles surrounding the heart and lungs, and some patients may eventually need a respirator. But distal muscular dystrophy usually advances slowly. Most patients will notice the first symptoms in their 40s, 50s, or 60s.
- Duchenne: The most common form of muscular dystrophy, Duchenne accounts for about 50 percent of all cases. It mostly affects boys, and symptoms start appearing in early childhood. Usually, muscle weakness first appears in the hips, shoulders, upper arms, and legs. Historically, children with Duchenne’s disease could only expect to live into their teenage years. But recent advances in care have improved life expectancy. With early diagnosis and aggressive medical care, patients today can survive to their 30s and 40s.
- Emery-Dreifuss: Primarily affecting boys, Emery-Dreifuss muscular dystrophy usually appears before the patient turns 10, but it has been diagnosed in older children too. Most patients will experience contractures, or muscle shortening, in the spine, neck, and limb joints. They might also experience muscle weakness and facial drooping. Almost everyone with Emery-Dreifuss will develop some kind of heart problem, and many require a pacemaker or cardiac device. Many patients die in early adulthood due to these cardiac complications.
- Facioscapulohumeral: For most affected patients, muscle weakness appears in the face, shoulders, and upper arms. Usually this weakness affects one side of the body more than the other. Symptoms usually occurs in childhood or young adulthood, but may rarely occur in middle life. An infantile onset form of FSH has also been described. The severity of the condition varies. Some patients can maintain a normal lifestyle, while others will need a wheelchair and respiratory assistance.
- Limb-girdle: This group of conditions is characterized by weakness in the muscles surrounding the shoulders and hips. Limb-girdle muscular dystrophy often progresses slowly, and sometimes the process of muscle degeneration stops temporarily. Symptoms can start in childhood, adolescence, or adulthood. Both sexes are equally at risk.
- Myotonic dystrophy: This condition, which usually affects the muscles in a patient’s face, often manifests itself in early teen years. The first symptom is usually facial contraction—patients are unable to relax facial muscles after moving them. Other disease features include muscle weakness, muscle atrophy and testicular atrophy in males. People with mild forms of myotonic dystrophy have a normal life expectancy. Myotonic dystrophy mostly affects members of the same family, although there are rare cases in which someone has the condition without having inherited it.
- Oculopharyngeal: This form of muscular dystrophy usually first causes drooping eyelids and weak muscles in the face and throat. Symptoms usually start in patients in their 40s and 50s and may lead to problems with vision and speech. Eventually, muscle weakness will also spread from the face and head to affect the shoulders, hips and limbs.
How is muscular dystrophy diagnosed?
In some cases, genetic tests performed on a patient’s blood can make a definitive diagnosis. Electrodiagnostic techniques such as nerve conduction studies (NCS) and electromyography (EMG) can evaluate nerve and muscle function, helping to identify the muscles impacted by the condition. Doctors may also conduct muscle biopsies to diagnose.
Early diagnosis of muscular dystrophy can help patients prepare for future symptoms and achieve a better quality of life. For patients with a family history of muscular dystrophy, genetic testing is available.
How is muscular dystrophy treated?
Patients with muscular dystrophy should be treated as soon as possible to improve quality of life and help prevent future complications. Treatment can help patients prevent dangerous falls and prepare for any heart or breathing problems that may arise. While there is no cure for muscular dystrophy, some patients can find relief from cramps or spasms by taking muscle relaxers.
Others may find that wearing orthotics on the legs can help preserve mobility. Eventually, surgery might be needed to correct severe spinal deformities, or release severe contractures (tendon tightening). Clinicians at Yale Medicine advise patients on strategies to change diet to softer foods that will make eating easier or to make in-home modifications to assist with better movement.
In extreme cases, breathing aids and feeding tubes may become a necessary part of treatment. Muscular dystrophy is also an area of active pharmaceutical research, with several drugs nearing approval.
These exploratory medications work in different ways—some work to slow down disease progression and maintain muscle function, while others employ so-called “gene editing” techniques to restore the body’s ability to create proteins essential for normal muscle maintenance. One drug, Ataluren, has already been approved in Europe to treat Duchenne muscular dystrophy.
How does muscular dystrophy affect quality of life?
“Each patient will have an individual experience, with different levels of functional decline,” said Huned Patwa, MD, co-director of the Neuromuscular Program. “Physicians are here to follow this disease, anticipate any problems a patient will have and make early response decisions.
“When patients receive treatment at a specialized muscular dystrophy clinic, higher patient satisfaction and better overall quality of life is reported,” said Patwa. In addition, most patients have primary caregivers, usually family members who take care of the growing needs. Caregivers of patients treated at MDA clinics report higher levels of satisfaction too, Patwa said.
What makes Yale Medicine's approach to muscular dystrophy unique?
For the last 20 years, Yale Medicine’s Neuromuscular Program has been a certified Muscular Dystrophy Association (MDA) program. That certification makes Yale Medicine one of 200 clinics in the country especially qualified to diagnose and treat patients with muscular dystrophy.
In addition, the Yale Medicine Muscular Dystrophy Program was the 13th clinic in the country to be named a Certified Duchenne Care Center by the nonprofit organization Parent Project Muscular Dystrophy.
Patients treated at Yale Medicine will have access to resources provided by MDA, such as financial services counseling. Yale clinicians are highly experienced neuromuscular disease specialists, with access to the best diagnostic tools available.
Since muscular dystrophy can lead to a wide array of symptoms, the clinic employs a multidisciplinary approach to treatment that involves experts in respiratory disorders, cardiac disorders, swallowing disorders, and pain management. Clinicians also have access to an on-campus wheelchair clinic and orthotics assessments. In addition to offering top quality clinical care, Yale Medicine researchers are also studying the cause of neuromuscular disorders and exploring potential treatments.