Muscular Dystrophy

Muscular dystrophy literally means the wasting away or atrophy of muscles.

The muscular dystrophies (MD) refer to the group of genetic diseases characterized by progressive weakness and degeneration of the skeletal muscles that control movement.  There are many forms of muscular dystrophy, some noticeable at birth known as congenital muscular dystrophy while other forms develop in adolescence (BECKER MD).  Regardless of the exact timing of onset, some muscular dystrophies lead to mobility impairment or even paralysis.

The three most common types of MD are: Duchenne, facioscapulohumeral, and myotonic.  These three types differ in terms of pattern of inheritance, age of onset, rate of progression, and distribution of weakness.

Duchenne MD

Duchenne MD primarily affects boys and is the result of mutations in the gene that regulates dystrophin – a protein involved in maintaining the integrity of muscle fiber.  Onset is between 3-5 years and progresses rapidly.  Most boys become unable to walk at 12, and by 20 have to use a respirator to breathe.

Facioscapulohumeral MD

Facioscapulohumeral MD appears in adolescence and causes progressive weakness in facial muscles and certain muscles in the arms and legs.  It progresses slowly and can vary in symptoms from mild to disabling.

Myotonic MD

Myotonic MD varies in the age of onset and is characterized by myotonia (prolonged muscle spasm) in the fingers and facial muscles: a floppy-footed, high-stepping gait; cataracts; cardiac abnormalities; and endocrine disturbances.  Individuals with myotonic MD have long faces and drooping eyelids; men have frontal baldness.

Is there any treatment?

There is no specific treatment for any of the various forms of MD.  Physical therapy is often practiced to prevent painful muscle contractures.  And / or certain prescribed drugs may be used for pain management as well as for arresting muscular deterioration within some forms of MD.  Orthopedic appliances are used for support while corrective orthopedic surgery may be required to improve the quality of life for others.  In some cases, respiratory therapy may be needed, as noted before.  Finally, cardiac abnormalities may require a pacemaker.

Sources

National Institute of Neurological Disorders and Stroke,  National Institutes of Health