Child Health A to Z

What is muscular dystrophy?

Muscular dystrophy (MD) is a group of inherited diseases that cause the muscles to weaken and degenerate. The muscles lack a key structural protein needed to work properly. The body loses muscle tissue and replaces it with fat and connective tissue. This can sometimes make the muscles look larger than normal. Despite the size of the muscles, children with muscular dystrophy have significant muscle weakness which makes walking difficult or even impossible. Currently, there is no cure but there are new efforts to offer better medical and supportive treatments. Meanwhile there are great strides on the research horizons including human clinical trials that are testing some of new gene and cell therapy endeavors.

There are many forms of muscular dystrophy. Duchenne muscular dystrophy (DMD) is the most common type and the most severe childhood form of the disease. It usually begins before the age of 5 and affects mostly boys. The life span for people with the disease is usually shortened to the 20s.

How does it occur?

MD is a typically a genetic disorder. This means that a child with MD has a defective gene. One or both parents may be a carrier of the gene and pass it on to their child, depending on the type of MD.

What are the symptoms?

All types of muscular dystrophy cause muscle weakness and lack of coordination. Signs of muscular dystrophy are often noticed when a child is very young. A child may appear clumsy and have a tendency to fall a lot.

A child with muscular dystrophy may also have:

• difficulty getting up from the ground
• an unusual, waddling gait
• toe-walk
• enlargement of the calf and other muscles
• learning, social and attention differences
• when older could develop cardiac issues

Symptoms of muscle weakness may be found in many other serious conditions. So, it is important to consult with your health care provider as soon as possible if you notice that your child has any muscle weakness.

How is it diagnosed?

Blood tests are done to check for MD. Children with MD usually have high levels of creatine kinase (CK), a muscle enzyme, in their blood. Other tests may include studying a small piece of muscle, called a muscle biopsy, or a test of muscle and nerve function.

How does MD progress?

The course of the disease is fairly predictable for children with Duchenne MD as a group but individual differences are expected. The child will begin having difficulty between 3 and 5 years of age with climbing stairs and getting off the ground. A wheelchair is usually needed by age 12. In most cases, the children develop tightness around the joints of their hips, knees, and ankles and can have a curved spine. Breathing problems and respiratory infections occur as the muscle weakness gets worse.

The heart is affected in many types of muscular dystrophy. As the breathing muscles weaken, lung problems, including pneumonia, may develop.

How is it treated?

Although there is no cure, symptoms of muscular dystrophy can be reduced by:

• Non-aggressive exercise programs and gentle physical therapy to minimize muscle shortening around the joints. Overexercising these vulnerable muscles may speed up the disease so activities such as swimming and bicycling are encouraged
• Corticosteroids may be offered as a trial. If the numerous side-effects are tolerated, there can be clear benefits to maintain walking longer (up to 2-3 years longer), straighter spines and better cardiorespiratory function.
• Neuropsychology and Developmental Evaluations to optimize learning and school services
• Nutrition/Dietician expertise
• Dedicated cardiac care which includes EKGs, ECHOCARDIOGRAMS and medicines if indicated
• Dedicated pulmonary care which includes pulmonary function tests, sleep studies, cough assist devices, CPAP/BiPap, etc.
• Dedicated endocrinology care for addressing steroids issues, bone density loss, growth impairments, etc.
• Orthotics and assistive aids, such as keyboards, walkers, manual and electric wheelchairs to maintain mobility
• Orthopedic surgery to relieve muscle shortening (contractures) and curvature of the spine.
• Genetic counseling
• Family support services

If breathing becomes difficult, a mechanical ventilation can be used to help, especially at night. There is a great deal of medical research going on to find better treatments and perhaps someday, a cure for this disease.

Can a special diet help my child?

A special diet cannot cure MD and vitamin therapy has not been proven to be a benefit either. However, nutrition for children with MD is very important and should be closely watched. Because MD tends to make children less active, many children with MD gain too much weight. Adequate calcium intake is essential for bone density health. Evidence-based research in employing various nutritional supplements are limited but some human and mouse muscular dystrophy studies have reported some benefit with creatine, CoQ10, anti-oxidants, arginine, Chinese green tea, etc. Watch your child's weight carefully and help him make good eating decisions that result in a healthy weight.

Where can I get more information?

Learn about this debilitating muscle condition. BrainPOP offers educational animated movies for kids. See this web-linked video http://www.brainpop.com/health/diseasesandconditions/duchennemusculardystrophy/

Parent Project Muscular Dystrophy (PPMD) http://www.parentprojectmd.org

The Muscular Dystrophy Association provides counseling, support, services, and research. Go to their Web site at http://www.mdausa.org or contact your local chapter for more information.