Muscular Dystrophy: Prognosis and Life Expectancy
Muscular dystrophy, or MD, is a group of degenerative diseases that causes weakness and loss of function in the muscles that control movement, and sometimes muscles of the heart and respiratory system. MD is progressive, meaning it worsens over time. Muscular dystrophy prognosis varies widely. Some forms of MD are mild and progress slowly; others are more severe and shorten life expectancy.
The most common type of MD is Duchenne, which affects young boys. While it is a serious form of the disease, medical advances have significantly extended the lifespan of boys with Duchenne. If you or your child is diagnosed with any form of MD, there are treatments to help extend life expectancy and maximize quality of life.
There are nine types of muscular dystrophy, all of which cause weakness and disability. Some forms progress over a normal lifespan. Others cause severe muscle weakness and loss of functional disability in a relatively quick time frame. Some forms of MD that are seen frequently are:
Duchenne: DMD almost always affects boys and typically develops around age 4. Weakness progresses from the core muscles in the trunk to the extremities. By age 12, many children have difficulty walking. DMD can also cause serious breathing problems and affect the heart muscles. Developments in cardiac and respiratory treatment as well as medication for muscle strength have improved the prognosis for some children with DMD. Many are able to go to school, marry and have children. Life expectancy can reach into the early thirties.
Becker: Becker MD is similar to Duchenne, but has a milder effect on muscle movement and appears in people aged anywhere from 5 to 60 years. Weakness first develops in the hips, pelvis, thighs and shoulders, and people with BMD may have thick calf muscles. It can damage the heart in the same way Duchenne does, but cardiac medication, such as ACE inhibitors or beta blockers, can help manage the impairment and people with BMD can have a good life expectancy.
Congenital: Children born with MD develop general muscle weakness and may also have joint deformities. There are several forms of congenital MD and life expectancy varies widely. The prognosis is generally poor; some babies with CMD die in infancy, while others live to young adulthood.
Myotonic: Myotonic MD affects adults, usually appearing between the ages of 20 and 40 years. All muscle groups are involved, but it typically affects the face, feet, hands and neck first. Myotonic MD progresses slowly, so the prognosis can be good, up to a normal life expectancy.
Emery-Driefuss: This form of MD appears in children and teens. Shoulders and upper arm muscles may weaken first, as well as the joints. It progresses slowly and people with Emery-Driefuss may be able to perform daily activities for many years. Heart irregularities that can quickly be fatal can develop in teenagers with Emery-Driefuss MD, so surgeons may implant a pacemaker to regulate the heartbeat or treat abnormalities with heart medication.
Though there is no cure for muscular dystrophy, treatment has improved the prognosis in terms of both quality and length of life for people living with MD. After a diagnosis, a medical team can help you with the following:
Physical and occupational therapy. These therapies help maintain muscle tone and flexibility. Braces can help prevent joints from stiffening or locking into uncomfortable positions that make it harder to move.
Medications. Eteplirsen (Exondys 51) may increase muscle strength. Emflaza (deflazacort) has an anti-inflammatory effect that may help repair damaged tissue. Steroids can also help strengthen muscles and may delay disease progression, but often come with significant side effects.
Assistive devices. Motorized wheelchairs, robotics, braces, gait trainers, walkers, crutches, and even adaptive bicycles can help people with MD maintain mobility and help with daily activities.
Respiratory and cardiac care. If breathing becomes difficult, people with MD can use a sleep apnea device to help at night. Some may require a ventilator to help them breathe. Respiratory infections are common, so preventive measures like vaccinations are important. When MD affects the heart muscle, medications or a pacemaker help regulate the heartbeat.
Back surgery. As muscles weaken, they may not be able to support the spine adequately. The spinal column can become curved, which is a condition called scoliosis. If the curve is severe, it can be painful and affect breathing. Surgery can straighten the spine and relieve discomfort.
Muscular dystrophy treatment has improved in recent years and there is a great deal of research into future treatments and possible cures. Though it is a serious disease, your medical team will work with you to manage symptoms and retain maximum mobility and life expectancy. Engaging with a support group and having a good social network is also beneficial and has a positive effect on quality of life.