What is Muscular Dystrophy? (click the title for details)
Muscular Dystrophy (MD) is a genetic disease characterized by progressive weakness and degeneration of the skeletal muscles, which control the body’s movement. Muscular Dystrophy takes on several forms, thus Muscular Dystrophy can be properly referred to as Muscular Dystrophies. Some of the forms of Muscular Dystrophy are detectable at birth these forms of Muscular Dystrophy are referred to as Congenital Muscular Dystrophy. However, others are detectable during the adolescence years, and are called Becker Muscular Dystrophy or Becker MD. The three most prevalent types of Muscular Dystrophy are as follows:
· Duchenne Muscular Dystrophy or Duchenne MD is found principally in young males. This form of Muscular Dystrophy is the result of mutations in the gene that regulates Dystrophin. Dystrophin is a protein utilized to help maintain muscle fibers. The disease is detectable in during the early years of a childs life (toddler years) and progresses rapidly. Most boys become unable to walk during their early teenage years, and by their early twenties require the use of a respirator to breathe.
· Facioscapulohumeral MuscularDystrophy or Facioscapulohumeral MD can be both mild and disabling in the severity of its symptoms. This form of Muscular Dystrophy appears during the adolescence years causing progressive weakness in the facial muscles as well as in the arms and legs.
· Myotonic Muscular Dystrophy or Myotonic MD varies in the age of onset and is characterized by Myotonia. Myotonias are prolonged muscle spasms in the fingers and facial muscles. Individuals with Myotonic Muscular Dystrophy are identifiable by their long faces and drooping eyelids (frontal baldness in men).
· Becker's muscular dystrophy (slowly progressive form of MD; affects legs and pelvis most severely)
· Duchenne's muscular dystrophy (similar to Becker's, but progresses more rapidly)
· Facioscapulohumeral muscular dystrophy (mild, slowly progressive form; face, shoulders, and upper arms affected)
· Limb-girdle muscular dystrophy
Disorders are distinguished by the type of inheritance (dominant genes, recessive gene, and so on), the age when symptoms appear, and the types of symptoms that develop. Because these are inherited disorders, risks include a family history of muscular dystrophy.
· muscle weakness
o frequent falls
o delayed development of muscle skills
o problems walking
o difficulty using a muscle group (the specific muscle affected depends on the type of MD)
o eyelid drooping (ptosis)
· intellectual retardation
o present in only some types of muscular dystrophy
· floppy, decreased muscle tone (hypotonia)
· skeletal deformities
· muscle deformities
Examination and history help to distinguish the type of MD. Different types of MD affect specific muscle groups. There often is a loss of muscle mass (wasting), which may be disguised in some types of muscular dystrophy by an accumulation of fat and connective tissue (pseudohypertrophy). Muscle contractures are common, which involve the inability to use the muscle because of shortening of the muscle fibers and fibrosis of the connective tissue. Some types of MD involve the heart muscle, causing irregular or inadequate heart pumping. Other points of note include:
· A muscle biopsy is the primary test used to confirm the diagnosis.
· A serum CPK (muscle enzyme) may be elevated.
· An EMG (electromyography) may confirm that weakness is caused by destruction of muscle tissue rather than damage to nerves.
None of the Muscular Dystrophies have a specific treatment available at present. Treatment is aimed at controlling symptoms to maximize the quality of life. Activity is encouraged to the degree tolerated. Inactivity (such as bedrest) can worsen the muscle disease. Physical therapy may be helpful to maintain muscle strength and functioning. Orthopedic appliances such as braces and wheelchairs may improve mobility and self-care abilities.