Muscular dystrophy (MD) is a group of genetic diseases that causes the muscles to weaken and eventually break down over time. Muscular dystrophy often affects the skeletal muscles that control movement. There are different types of muscular dystrophy that may vary in symptoms, severity, rate of progression, and the age that symptoms may develop. While there is no cure for muscular dystrophy, there are treatments and therapies available to help slow the progression of the disease. Most cases of muscular dystrophy are caused by an inherited genetic mutation, however, some cases occur spontaneously with no evidence of a genetic link.
Symptoms of Muscular Dystrophy
The most common symptoms of muscular dystrophy are gradual weakening of muscles and lack of coordination. There are several different types of muscular dystrophy and the symptoms of each type may vary in characteristics, age of onset and progression of the disease.
Duchenne is the most common form of MD and primarily affects boys. Symptoms typically occur when children begin walking and may include frequent falls, trouble running, waddling gait, large calve muscles, and difficulty getting up from a sitting position. This type of MD tends to progress rapidly.
Symptoms of Becker muscular dystrophy are similar to those of Duchenne, but tend to be milder and progress more slowly. Symptoms commonly begin in the teenage years or during the early twenties.
Myotonic muscular dystrophy is characterized by an inability to relax muscles. Symptoms may include muscle spasms, mental deficiency, hair loss and cataracts. It often occurs in early adulthood and initially affects the muscles of the face.
Limb-girdle muscular dystrophy initially affects the hip and shoulder muscles. In some instances, it may be difficult to lift or move one or both feet. Symptoms may initially occur in childhood or in adults.
Symptoms of Fascioscapulohumeral (FSHD) muscular dystrophy often occur in teens or young adults. Muscle weakness affects the face, shoulder and upper arms. FSHD also causes weakness in the muscles of the eyes and mouth. The shoulder blades of individuals with FSHD may also protrude when they raise their arms.
Oculopharyngeal MD is often characterized by the drooping of the eyelids. Oculopharyngeal muscular dystrophy may also cause weakness of the eye muscles, face and throat and may result in swallowing difficulties. Symptoms commonly first appear in adulthood, usually in individuals over the age of 40.
Complications of Muscular Dystrophy
When muscular dystrophy affects the muscles that are associated with breathing, respiratory failure may occur. Certain types of muscular dystrophy can also affect the heart muscle, resulting in serious heart problems. Nutritional deficiencies may occur as a result of weakness in the muscles used for swallowing. As muscle weakness in other parts of the body progresses, mobility becomes a problem and many people with muscular dystrophy may eventually need to use a wheelchair.
Diagnosis of Muscular Dystrophy
Muscular dystrophy may be diagnosed after a review of symptoms and a complete physical examination. Enzyme tests may be administered to check the levels of creatine kinase in the blood, which may indicate a muscle disease. Additional diagnostic tests may include:
- Muscle biopsy
- Genetic testing
Treatment of Muscular Dystrophy
While there is no cure for muscular dystrophy, there are several treatment options available to manage the symptoms of the condition and maximize quality of life. Treatment for muscular dystrophy may include medication such as corticosteroids, to help improve muscle strength and slow the progression of muscle weakness. Physical therapy may be effective at providing exercise to keep joints flexible and improve mobility. Assistive devices such as canes, braces, walkers or wheelchairs can help individuals maintain mobility. A ventilator may be used to assist with breathing when respiratory muscles have weakened. If the heart muscle has been affected, a pacemaker may be inserted to regulate heart rate. Surgery may be required in certain cases, to release tendons or correct abnormalities of the spine.