Muscular dystrophy

Muscular dystrophy is a group of rare diseases that cause muscles to weaken and deteriorate over time. In muscular dystrophy, genes mutate and prohibit the production of proteins that are building blocks of healthy muscle.

There are many kinds of muscular dystrophy, with the most common variety beginning mostly with boys in childhood. Other types don’t surface until adulthood.

What causes muscular dystrophy?

Certain genes are involved in making proteins that protect muscle fibers. Muscular dystrophy (MD) occurs when one of these genes is defective.

There are nine types of muscular dystrophy, each with varying age of onset, symptoms, rate of progression and life expectancy.

Treatments are available

Although there’s no cure for any form of muscular dystrophy, treatments for certain forms of the disease can help extend the time a person with the disease can stay active, allowing them to live a mostly normal life.

What are the signs of muscular dystrophy?

The main sign of muscular dystrophy is progressive muscle weakness. Specific signs and symptoms begin at different ages and in different muscle groups, depending on the type of muscular dystrophy.

Signs and symptoms, which typically appear in early childhood, might include:

  • Delayed growth.
  • Difficulty rising from a lying or sitting position.
  • Frequent falls.
  • Large calf muscles.
  • Learning disabilities.
  • Muscle pain and stiffness.
  • Trouble running and jumping.
  • Waddling gait.
  • Walking on the toes.

Diagnosing muscular dystrophy

Your specialist is likely to start their diagnosis by reviewing medical history and performing a physical examination. After that, they might recommend:

  • Electromyography. An electrode needle measures electrical activity is measured in a muscle, helping to confirm a muscle disease.
  • Enzyme tests. Checking blood levels for high amounts of enzymes, such as creatine kinase (CK), can suggest a muscle disease.
  • Genetic testing. Doctors can look for gene mutations in blood samples that cause muscular dystrophy.

  • Heart-monitoring tests. These tests are used to check heart function.
  • Lung-monitoring tests. These tests are used to check lung function.
  • Muscle biopsy. A small piece of muscle can be removed through an incision or with a hollow needle and then be analyzed to determine if any muscular dystrophies are present.

Treatments for muscular dystrophy

Although there’s no cure for any form of muscular dystrophy, treatments for certain forms of the disease can help extend the time a person with the disease can stay active, allowing them to live a mostly normal life. Because muscular dystrophy can impact so many areas of the body, treatment options include medications, physical and occupational therapy, and surgeries and other procedures.

Medications

Your doctor might recommend:

  • Corticosteroids are effective at strengthening muscle while slowing the advance of certain types of the disease.
  • Medications specifically designed to treat certain forms of muscular dystrophy.
  • Certain heart medications.

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Therapy

There are several therapy options available for people who have muscular dystrophy. Whether recommended individually or implemented together, these therapies and assistive devices can help improve both the length and quality of life.

Examples include:

  • Braces. Braces aid mobility and support weakened muscles.
  • Breathing assistance. Depending on the severity of the muscular dystrophy, a sleep apnea device or a ventilator may be used to assist weakened breathing muscles.
  • Exercise. Low-impact aerobic exercise, such as walking and swimming, can help maintain strength, mobility, and general health. Some types of strengthening exercises also might be helpful.
  • Mobility aids. Canes, walkers, and wheelchairs can help maintain mobility and independence.

Surgery

Surgery can be used to correct any deformities in the spine that could eventually make breathing more difficult. Heart function may be improved with a pacemaker or other cardiac device.

Frequently asked questions (FAQs) about muscular dystrophy

Yes. Each form of muscular dystrophy is caused by genetic mutations, with most of the mutations being inherited.

According to the National Institute of Neurological Disorders and Stroke, the prognosis for people with MD varies according to the type and progression of the disorder.

Some cases may be mild and progress very slowly over a normal lifespan, while others produce severe muscle weakness, functional disability, and loss of the ability to walk. Some children with MD die in infancy, while others live into adulthood with only moderate disability.

According to the National Library of Medicine, the severity of disability depends on the type of muscular dystrophy. All types of muscular dystrophy slowly get worse, but the rate at which this happens varies from patient to patient.

Some types of muscular dystrophy, such as Duchenne muscular dystrophy in boys, are deadly. Other types cause little disability, and people with the disease have a normal lifespan.

While MD mostly impacts muscles, it depends on the type of muscular dystrophy. For example, Myotonic muscular dystrophy (MMD) is a complex disease that affects many systems in the body and brain.

There are nine types of muscular dystrophy, each with varying age of onset, symptoms, rate of progression and life expectancy.

Becker muscular dystrophy. Signs and symptoms are similar to those of Duchenne muscular dystrophy (see below), but tend to be milder and progress more slowly. Symptoms generally begin in the teens but might not occur until the mid-20s or later.

Congenital. This type affects boys and girls and is apparent at birth or before age 2. Some forms progress slowly and cause only mild disability, while others progress rapidly and cause severe impairment.

Distal. Symptoms include weakness and wasting of muscles of the hands, forearms, and lower legs. Progression is slow and rarely leads to total incapacity. Onset begins between 40 to 60 years of age.

Duchenne type muscular dystrophy. The most common form of muscular dystrophy, Duchenne muscular dystrophy is caused by a defective gene of a protein in the muscles called dystrophin. Although girls can be carriers and mildly affected, it’s much more common in boys, affecting roughly 1 in 3,600 male infants. Onset occurs between 2 to 6 years of age.

Emery-Dreifuss. Symptoms include weakness and wasting of shoulder, upper arm, and shin muscles; joint deformities are common; progression is slow; sudden death may occur from cardiac problems. Onset begins between childhood and early teens.

Facioscapulohumeral (FSHD). Muscle weakness typically begins in the face, hip and shoulders. The shoulder blades might stick out like wings when arms are raised. Onset usually occurs in the teenage years but can begin in childhood or as late as age 50.

Limb-girdle. Hip and shoulder muscles are usually affected first. People with this type of muscular dystrophy might have difficulty lifting the front part of the foot and so might trip frequently. Onset usually begins in childhood or the teenage years.

Myotonic. This is characterized by an inability to relax muscles following contractions. Facial and neck muscles are usually the first to be affected. People with this form typically have long, thin faces, drooping eyelids, and swanlike necks. Onset begins between 20 and 40 years of age.

Oculopharyngeal. Symptoms affect muscles of eyelids and throat causing weakening of throat muscles, which, in time, causes inability to swallow and emaciation from lack of food; progression is slow. Onset begins between 40 to 70 years old.