Muscular dystrophy

• Becker's muscular dystrophy
• Duchenne's muscular dystrophy
• facioscapulohumeral muscular dystrophy
• limb-girdle muscular dystrophy
• Emery-Dreifuss muscular dystrophy
• myotonic dystrophy
• myotonia congenita

Disorders are distinguished by the type of inheritance ( sex-linked, dominant genes , or 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.

Lambert-Eaton syndrome and myasthenia gravis have symptoms that may be similar to early stages of some types of muscular dystrophies.

Prevention:
Genetic counseling is advised when there is a family history of
muscular dystrophy. Women may be asymptomatic but still be carriers of the gene for the disorder. Duchenne's muscular dystrophy can be detected with about 95 percent accuracy by genetic studies performed during pregnancy .

Symptoms:
Symptoms vary with the different types of muscular dystrophy. Certain types, such as Duchenne dystrophy, are ultimately fatal while other types have associated muscle weakness but cause little disability.

• muscle weakness
• progressive
• frequent falls
• delayed development of muscle skills
• problems walking
• difficulty using a muscle group (the specific muscle affected depends on the type of MD)
• eyelid drooping ( ptosis )
• drooling
• intellectual retardation
• only present in some types of MD
• hypotonia
• skeletal deformities
• muscle deformities
• contracture deformities (clawfoot, clawhand or others)
• scoliosis
• enlargement of the calve muscles (pseudohypertrophy)

Signs and Tests:

Examination and history help to distinguish the type of MD. Specific muscle groups are affected by different types of MD. Often, there 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 making the muscle appear larger (pseudohypertrophy). Muscle contractures are common. Shortening of the muscle fibers, fibrosis of the connective tissue and scarring slowly destroy muscle function. Some types of MD involve the heart muscle, causing cardiomyopathy or arrhythmias .

• A muscle biopsy is the primary test used to confirm the diagnosis.
• A serum CPK may be elevated.
• An EMG ( electromyography ) may confirm that weakness is caused by destruction of muscle tissue rather than damage to nerves.
• An ECG (electrocardiography) to monotor changes in cardiac status

This disease may also alter the results of the following tests:

• myoglobin - urine
• myoglobin - serum
• LDH isoenzymes
• LDH
• creatinine - urine
• creatinine
• CPK isoenzymes
• AST
• aldolase

Treatment:

There is no known cures for the various muscular dystrophies. 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.

The stress of illness can often be helped by joining support groups where members share common experiences and problems. See muscular dystrophy - support group .

Prognosis:
The outcome varies with the type of muscular dystrophy. All types of MD progressively worsen, but the speed and extent of disability varies.

Complications:

• deformities
• permanent, progressive disability
• decreased mobility
• decreased ability to care for self
• mental impairment (varies)
• cardiomyopathy
• respiratory failure (can cause death)

Call Your Healthcare Provider:

Call your health care provider if the symptoms indicate muscular dystrophy may be present.
Call for an appointment with your health care provider if there is a personal or family history of muscular dystrophy and children are planned.