What Is It?
Muscular dystrophy refers to a group of genetic (inherited) conditions that cause the body's muscles to deteriorate slowly over time, and become increasingly weak. Types of muscular dystrophy include:
In addition, there are at least two other forms of the illness: congenital muscular dystrophy and humeroperoneal muscular dystrophy (Emery-Dreifuss dystrophy). Some forms of congenital muscular dystrophy are associated with decreased mental function. Humeroperoneal muscular dystrophy causes upper arm and lower leg weakness, as well as poor heart function.
Symptoms of muscular dystrophy, as well as the age the condition usually starts vary according to the specific form of illness:
Your doctor will review the patient's medical history and symptoms. If the patient is a child, the doctor will ask about your child's developmental history (age of first sitting, standing, walking), history of infections, and any significant injuries.
Your doctor will examine you or your child, paying special attention to the muscles. He or she will look for muscle weakness, wasting and myotonia and will do a neurological examination to look for nerve problems. To confirm the diagnosis of muscular dystrophy, your doctor may order:
All forms of muscular dystrophy continue to worsen and persist throughout life.
There is no way to prevent muscular dystrophy. Genetic testing of potential parents (usually a simple blood test) can help to determine the chances of having a child with the one of these disorders.
There is no cure for muscular dystrophy and no way to stop it from getting worse. In general, patients are given supportive care, together with leg braces and physiotherapy to help them function in daily life. It's particularly important that limbs be stretched to avoid tightened tendons and muscles. When tightness of tendons (contractures) develops, surgery can be done. When chest muscles are involved, respiratory therapy may be used to delay breathing problems. In addition, people with muscular dystrophy are given age-appropriate dietary therapy to help them follow a healthy meal plan while avoiding obesity. Obesity is especially harmful to patients with muscular dystrophy because it places additional strain on their weak muscles. Unfortunately, many people with muscular dystrophy are at a high risk of obesity because their physical limitations prevent them from exercising. Some forms of muscular dystrophy involve the heart; for these, evaluation of heart function and rhythm is recommended. Medications to improve heart function and rhythm or a pacemaker to maintain a normal heart rate may be helpful.
In boys with Duchenne dystrophy, corticosteroids (such as prednisone) may be prescribed to temporarily keep the illness from getting worse. However, some people cannot tolerate this medication because of side effects. Becker muscular dystrophy is sometimes treated with corticosteroids, although its effects are less reliably effective. Powerful medications that suppress the immune system have been reported to help some patients, but their use is controversial and somewhat risky. Other experimental treatments are being developed, including gene therapy, in which abnormal muscular dystrophy genes are replaced with healthy ones.
In patients with myotonic dystrophy, muscle contractions can be treated with medications such as mexiletine (Mexitil) or phenytoin (Dilantin).
When To Call a Professional
If you are an adult, call your doctor if you notice muscle weakness anywhere in your body or if you notice that you have trouble speaking clearly or swallowing normally. If you are a parent, call your child's physician if your child has unusually frequent falls, has trouble getting up from the ground, or has trouble walking or running.
The outlook varies according to the type of muscular dystrophy and how quickly it worsens. Some patients have only mild symptoms with a normal lifespan, whereas others have severe symptoms and die at a young age. For example, boys with Duchenne dystrophy often die before age 18 because of respiratory failure, heart failure, pneumonia or other problems. Boys with Becker-type muscular dystrophy typically survive into their 30s.
Most people with facioscapulohumeral muscular dystrophy have muscle weakness limited to the face, neck and upper body, and their heart function and breathing usually are not affected.
National Institute of Neurological Disorders and Stroke
P.O. Box 5801
Bethesda, MD 20824
Muscular Dystrophy Association
3300 E. Sunrise Drive
Tucson, AZ 85718
Parent Project Muscular Dystrophy
158 Linwood Plaza, Suite 220
Fort Lee, NJ 07024