Muscular Dystrophy
Muscular dystrophy is a group of inherited diseases that are characterized by weakness and wasting away of muscle tissue. Sometimes, there is also the breakdown of nerve tissue. There are nine types of muscular dystrophy, with each type involving an eventual loss of strength, increasing disability and possible deformity. Other health problems commonly associated with muscular dystrophy include heart problems, scoliosis and obesity.
What are the types of muscular dystrophy?
The most well known type of muscular dystrophy is Duchenne muscular dystrophy (DMD), followed by Becker muscular dystrophy (BMD). For a complete list of muscles diseases, visit the Muscular Dystrophy Association.
What causes muscular dystrophy?
Duchenne muscular dystrophy is a genetic disease which means it is inherited. It is caused by an X-linked recessive gene. “X-linked” means that the gene causing the trait or the disorder is located on the X chromosome. Genes on the X chromosome can be recessive or dominant, and their expression in females and males is not the same because the genes on the Y chromosome do not exactly pair up with the genes on the X. X-linked recessive genes are expressed in females only if there are two copies of the gene (one on each X chromosome). However, for males there only needs to be one copy of an X-linked recessive gene in order for the trait or disorder to be expressed. For example, a woman can carry a recessive gene on one of the X chromosomes unknowingly, and pass it on to a son, who will express the trait or disease.
What are the symptoms of muscular dystrophy?
Muscular dystrophy is usually diagnosed in children between 3 and 6 years of age. Early signs of the illness include a delay in walking, difficulty rising from a sitting or lying position and frequent falling, with weakness usually affecting the shoulder and pelvic muscle at first. The following are the most common symptoms of muscular dystrophy:
- Clumsy movement
- Difficulty climbing stairs
- Frequently trips and falls
- Unable to jump or hop normally
- Tip toe walking
- Leg pain
- Facial weakness
- Inability to close eyes or whistle
- Shoulder and arm weakness
A tell-tale clinical characteristic for Duchenne muscular dystrophy (DMD) is Gowers’ sign. Children with Duchenne muscular dystrophy find it very hard to get up from a sitting or lying position on the floor. They first pull up to their hands and knees. The child walks his or her hands up their legs to brace themselves as they rise to a standing position.
In addition, children with muscular dystrophy often have very large calves due to the large amounts of fatty deposits that are replacing muscle.
How is muscular dystrophy diagnosed?
The diagnosis of muscular dystrophy is made with a physical examination and diagnostic testing by your child’s doctor. Diagnostic tests for muscular dystrophy may include:
- Blood tests. These will check muscle enzyme levels and genetic abnormalities.
- Muscle biopsy. This is the primary test used to confirm diagnosis. A small sample of muscle tissue is taken and examined under a microscope.
- Electromyogram (EMG). This test is used to check if the muscle weakness is a result of destruction of muscle tissue rather than nerve damage.
- Electrocardiogram (EKG). This test records the electrical activity of the heart, shows abnormal rhythms (arrhythmias or dysrhythmias) and detects heart muscle damage.
How is muscular dystrophy treated?
To date, there is no known treatment, medicine or surgery that will cure muscular dystrophy, or stop the muscles from weakening. Since muscular dystrophy is a lifelong condition that is not correctable, we focus on preventing or minimizing deformities and maximizing the child’s functional ability at home and in the community.
Management of muscular dystrophy is either nonsurgical or surgical. Nonsurgical interventions may include:
- Physical therapy.
- Positioning aids used to help the child sit, lie or stand.
- Braces and splints used to prevent deformity, promote support or provide protection.
- Medications, including steroids.
- Nutritional counseling.
- Psychological counseling.
Surgical interventions may be considered to manage the following conditions:
- Scoliosis (a sideways curvature of the back bones)
- Maintaining the child’s ability to sit or stand.
What is the long-term outlook for a child with muscular dystrophy?
Muscular dystrophy is a progressive condition that needs life-long management to prevent deformity and complications. Walking and sitting often becomes more difficult as the child grows. Usually by the age of 12, the child needs a wheelchair because the leg muscles are too weak to work. Heart or lung problems often occur by the late teenage years or into the early 20s.
Our interdisciplinary team will work with your family to improve your child’s function and to provide support as you learn to care for your child’s needs. The Muscular Dystrophy Association can be an important resource, both financially and emotionally, for parents of children with muscular dystrophy. Learn more about the MDA.