Definition

Muscular dystrophy is a group of disorders that cause muscle weakness over time. The different forms are:

• Duchenne dystrophy (most common)
• Becker dystrophy, which is a milder form of Duchenne dystrophy
• Myotonic muscular dystrophy, which can begin in late adulthood
• Facioscapulohumeral muscular dystrophy, which affects the muscles of the face, shoulder blades, and upper arms
• Congenital muscular dystrophy, which is found at or near birth and results in overall muscle weakness
• Distal muscular dystrophy, which affects the distal muscles of the lower arms, hands, lower legs, and feet
• Emery-Dreifuss muscular dystrophy, which affects the muscles of the shoulders, upper arms, and calf muscles
• Limb-girdle muscular dystrophy, which affects the muscles around the hips and shoulders
• Oculopharyngeal muscular dystrophy, which affects swallowing and the ability to keep the eyes open

Causes

This condition is caused by changes in genes. These changes cause problems with how the body makes proteins that are needed for healthy muscles. Each form of the disease is caused by a different faulty gene. Some of these genes are passed from parent to child.

Risk Factors

Duchenne dystrophy and Becker dystrophy are more common in boys.

The risk of muscular dystrophy is also higher in people who have a family member who have it.

Symptoms

The main symptom is muscle weakness that gets worse over time. Other symptoms depend on the type of muscular dystrophy a person has.

Other symptoms that are common in most forms are:

• Muscles that get larger as they weaken
• Muscle cramping
• Clumsiness
• Frequent falling and problems getting up
• Stiff, contracting muscles

Severe Muscle Contraction of the Hand Copyright © Nucleus Medical Media, Inc.

Symptoms of Duchenne and Becker dystrophy are:

• Weakening of the muscles closest to the trunk with later weakening of muscles that are further away from the trunk
• Enlarged calf muscles
• Abnormally curved spine
• Problems breathing
• Problems learning

Symptoms of myotonic muscular dystrophy are:

• Problems letting go after a handshake
• Problems learning
• Excessive sleeping

Diagnosis

The doctor will ask about your symptoms and health history. A physical exam will be done.

Blood tests will be done. The tests will look for enzymes released by damaged muscles. Tests will also look for changes in genes.

A muscle biopsy may be done. It will identify the type of muscular dystrophy

Muscles and nerves may be tested. This can be done with:

• Electromyogram (EMG)
• Nerve conduction study (NCS)

Treatment

There is no cure. The goal of treatment is to manage symptoms. Choices are:

• Physical therapy to strengthen muscles and improve range of motion
• Improving movement with supportive devices, such as walkers
• Medicines, such as:
  • Corticosteroids to ease muscle weakness
  • Creatine supplements to ease fatigue and increase strength
  • Medicines to treat other symptoms, such as heart problems

People with severe symptoms may need surgery. Surgery may be done to release tight muscles or to insert a pacemaker to treat heart problems.

Prevention

There are no known guidelines to prevent this disease.