Muscular dystrophy Health Article

Definition

Muscular dystrophy is a group of disorders that involve muscle weakness and loss of muscle tissue that get worse over time.

Alternative Names

Inherited myopathy; MD

Causes, incidence, and risk factors

Many diseases called muscular dystrophies (MD) are inherited disorders, such as:

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

Symptoms

Symptoms vary with the different types of muscular dystrophy.

All of the muscles may be affected. Or, only specific groups of muscles may be affected, such as those around the pelvis, shoulder, or face. Muscular dystrophy can affect adults, but the more severe forms tend to occur in early childhood.

Symptoms include:

• Mental retardation (only present in some types of the condition)
• Muscle weakness that slowly gets worse
  • Delayed development of muscle motor skills
  • Difficulty using one or more muscle groups
  • Drooling
  • Eyelid drooping (ptosis)
  • Frequent falls
  • Problems walking (delayed walking)

Signs and tests

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.

Signs may include:

• Curved spine (scoliosis)
• Joint contractures (clubfoot, clawhand, or others)
• Low muscle tone (hypotonia)

Some types of muscular dystrophy involve the heart muscle, causing cardiomyopathy or disturbed heart rhythm (arrhythmias).

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:

• Electrocardiography (ECG)
• Electromyography (EMG)
• Serum CPK

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

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