Inherited myopathy; MD

The group of diseases called muscular dystrophies (MD) includes many inherited disorders, such as:

• Becker's muscular dystrophy
• Duchenne muscular dystrophy
• Facioscapulohumeral muscular dystrophy
• Limb-girdle muscular dystrophy
• Emery-Dreifuss muscular dystrophy
• Myotonic dystrophy
• Myotonia congenita

Lambert-Eaton syndrome and myasthenia gravis also have symptoms that may be similar to early stages of some types of muscular dystrophies, so these disorders must be ruled out before muscular dystrophy is diagnosed.

Symptoms vary with the different types of muscular dystrophy. Some types, such as Duchenne muscular dystrophy, are deadly, while other types cause little disability and are associated with normal life span.

The muscles affected vary, but can be around the pelvis, shoulder, face or elsewhere. Muscular dystrophy can affect adults, but the more severe forms tend to occur in early childhood.

Symptoms include:

• Muscle weakness that slowly gets worse
  • Frequent falls
  • Delayed development of muscle motor skills
  • Problems walking (delayed walking)
  • Difficulty using one or more muscle groups
  • Eyelid drooping (ptosis)
  • Drooling
• Mental retardation (only present in some types of the condition)
• Hypotonia (low muscle tone)
• Joint contractures (clubfoot, clawhand, or others)
• Scoliosis (curved spine)

Some types of muscular dystrophy involve the heart muscle, causing cardiomyopathy or arrhythmias.

A physical examination and your medical history will help the doctor determine the type of muscular dystrophy. Specific muscle groups are affected by different types of muscular dystrophy.

Often, there is a loss of muscle mass (wasting), which may be hard to see because some types of muscular dystrophy cause a build up of fat and connective tissue that makes the muscle appear larger. This is called pseudohypertrophy.

A muscle biopsy may be used to confirm the diagnosis. In some cases, a DNA blood test may be all that is needed.

Other tests may include:

• Serum CPK
• EMG (electromyography)
• ECG (electrocardiography)

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

• Myoglobin - urine/ serum
• LDH
• Creatinine
• AST
• Aldolase

There are no known cures for the various muscular dystrophies. The goal of treatment is to control symptoms.

Physical therapy may help patients maintain muscle strength and function. Orthopedic appliances such as braces and wheelchairs can improve mobility and self-care abilities. In some cases, surgery on the spine or legs may help improve function.

Corticosteroids taken by mouth are sometimes prescribed to children to keep them walking for as along as possible.

The person should be as active as possible. Complete inactivity (such as bedrest) can make the disease worse.

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

The severity of disability depends on the type of muscular dystrophy. All types of muscular dystrophy slowly get worse, but how fast this happens widely varies. Some types of muscular dystrophy are deadly.

• Scoliosis
• Joint contractures
• Decreased mobility
• Decreased ability to care for self
• Mental impairment (varies)
• Cardiomyopathy
• Respiratory failure

Call your health care provider if the symptoms suggestive of muscular dystrophy occur.

Call your health care provider if there is a personal or family history of muscular dystrophy and you are planning to have children.

Genetic counseling is advised when there is a family history of muscular dystrophy. Women may have no symptoms but still carry the gene for the disorder. Duchenne muscular dystrophy can be detected with about 95% accuracy by genetic studies performed during pregnancy.