What is Inclusion Body Myositis ?

Inclusion body myositis (IBM) is a slowly progressive inflammatory disorder of muscle. Men over age 50 are most commonly affected. Symptoms include muscle weakness most commonly in the wrist, knees and ankles. and thinning of the muscles. One possible symptom is difficulty swallowing. The symptoms start with a gradual onset and affect most muscles. IBM causes no pain and does not shorten one's lifespan.

What causes Inclusion Body Myositis ?

The cause of IBM is not certain. Some theories state that IBM is a form of an autoimmune disorder. This means that the immune system continues to fight once an infection or virus is gone, so it destroys the healthy tissues within the body much like occurs in rheumatoid arthritis. Another theory is that IBM is a degenerative disease of the muscle and that the inflammation related to IBM is a result of something else. Lastly, it is known that the disease may be inherited, although it is rare.

How is Inclusion Body Myositis diagnosed?

The diagnosis of IBM can be made when characteristic changes are seen on a muscle biopsy specimen. Reading the results of blood tests, MRIs and EMGs can also make the diagnosis.

How is Inclusion Body Myositis treated?

Occasional patients have been reported to improve with intravenous gammaglobulin or steroids. A decrease in mobility may be slowed by physical therapy. However, the overall response to treatment plans such as these is poor.

More information on Inclusion Body Myositis

Myositis Association of America
Muscular Dystrophy Association