Inclusion Body Myositis

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What is inclusion body myositis?

Inclusion body myositis (IBM) is one of a group of muscle diseases known as the inflammatory myopathies, which are characterized by chronic, progressive muscle inflammation accompanied by muscle weakness. 

The onset of muscle weakness in IBM is generally gradual (over months or years) and affects both proximal (close to the chest) and distal (further away from the chest) muscles. Muscle weakness may affect only one side of the body. Falling and tripping are usually the first noticeable symptoms. For some individuals, the disorder begins with weakness in the wrists and fingers that causes difficulty with:

  • Pinching
  • Buttoning
  • Gripping objects

There may be weakness of the wrist and finger muscles and atrophy (thinning or loss of muscle bulk) of the forearm muscles and quadricep muscles in the legs. Difficulty swallowing occurs in approximately half of IBM cases.

Symptoms of the disease usually begin after the age of 50, although the disease can occur earlier. IBM occurs more frequently in men than in women.

There is no cure for IBM, nor is there a standard course of treatment. The disease is generally unresponsive to corticosteroids and immunosuppressive drugs. Some evidence suggests that intravenous immunoglobulin may have a slight, but short-lasting, beneficial effect in a small number of cases. Physical therapy may be helpful in maintaining mobility. Other therapy is symptomatic and supportive.

However, IBM is generally resistant to all therapies and its rate of progression appears to be unaffected by currently available treatments.

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Learn About Clinical Trials
Clinical trials are studies that allow us to learn more about disorders and improve care. They can help connect patients with new and upcoming treatment options.

How can I or my loved one help improve care for people with inclusion body myositis?

Consider participating in a clinical trial so clinicians and scientists can learn more about IBM and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with IBM at Clinicaltrials.gov.

Where can I find more information about inclusion body myositis?

Information may be available from the following resources:

Autoimmune Association
Phone: 586-776-3900

MedlinePlus

Myositis Association
Phone: 703-299-4850; 800-821-7356

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