Alternative names
Muscle wasting; Muscle atrophy; Atrophy of the muscles

Definition
Muscle atrophy refers to the wasting or loss of muscle tissue resulting from disease or lack of use.

Considerations

The majority of muscle atrophy in the general population results from disuse. People with sedentary jobs and senior citizens with decreased activity can lose muscle tone and develop significant atrophy. This type of atrophy is reversible with vigorous exercise. Bed-ridden people can undergo significant muscle wasting. Astronauts, free of the gravitational pull of Earth, can develop decreased muscle tone and loss of calcium from their bones following just a few days of weightlessness.

Muscle atrophy resulting from disease rather than disuse is generally one of two types, that resulting from damage to the nerves that supply the muscles, and disease of the muscle itself.

Examples of diseases affecting the nerves that control muscles would be poliomyelitis, amyotrophic lateral sclerosis (ALS or Lou Gehrig’s disease), and Guillain-Barre syndrome. Examples of diseases affecting primarily the muscles would include muscular dystrophy, myotonia congenita, and myotonic dystrophy as well as other congenital, inflammatory, or metabolic myopathies (muscle diseases).

Even minor muscle atrophy usually results in some loss of mobility or power.

Common Causes

 
• some atrophy that occurs normally with aging  
• cerebrovascular accident (stroke)  
• spinal cord injury  
• peripheral nerve injury (peripheral neuropathy)  
• other injury  
• prolonged immobilization  
• osteoarthritis  
• rheumatoid arthritis  
• prolonged corticosteroid therapy  
• diabetes (diabetic neuropathy)  
• burns  
• poliomyelitis  
• amyotrophic lateral sclerosis (ALS or Lou Gehrig’s disease)  
• Guillain-Barre syndrome  
• muscular dystrophy  
• myotonia congenita  
• myotonic dystrophy  
• myopathy

Home Care
Application of moist heat is recommended along with whirlpool baths and resistive exercises.

Unless prohibited by the doctor, active exercises are recommended where a full range of motion is achieved. Exercises using braces or splints are recommended for those who cannot actively move one or more joints.

Call your health care provider if

 
• there is any unexplained, prolonged muscle atrophy. What to expect at your health care provider’s office The medical history will be obtained and a physical examination performed. Medical history questions documenting muscle atrophy in detail may include:
   
  • time pattern       o When did it begin?       o Is it getting worse?  
  • location       o What muscle is affected?  
  • other       o What other symptoms are present?

  The extent of atrophy will be determined by observation and limb circumference measurements.

  Diagnostic tests that may be performed include:

   
  • CT scans of affected area  
  • electromyography  
  • muscle biopsy  
  • nerve conduction studies  
  • X-rays of affected area  
  • ultrasound therapy and in some cases, surgery (to correct a contracture)

  AFTER SEEING YOUR HEALTH CARE PROVIDER:
  You may want to add a diagnosis related to muscle atrophy to your personal medical record.

  

  Last revised: December 4, 2012
  by Harutyun Medina, M.D.
  
  

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  All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.