Myositis

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton  

Introduction

Myositis is a group of rare conditions where the body’s immune system turns against itself and destroys healthy muscle tissue instead of building new muscle tissue. Myositis is also known as idiopathic inflammatory myopathies (IIMs). This set of acquired diseases affect the muscle but may additionally affect other organs. Myositis mainly occur in middle-aged patients, most showing a subacute weakness and myalgia in the upper and lower limbs.

Sub-Types

Include these types:

• Dermatomyositis, which can affect the muscle and presents with a typical skin rash.
• Inclusion body myositis, with a purely muscular expression and leads to a slow progressive deficit
• Immune-mediated necrotizing myopathies, with a severe muscle involvement often presents from the onset of the disease
• Antisynthetase syndrome, which combines muscle damage, joint involvement and a potentially life-threatening lung disease
• Overlapping myositis, which combines muscle damage with other organs involvement connected to another autoimmune disease.

Diagnosis of Myositis

Diagnosis is based on diligent clinical examination, electromyographic studies and immunological testing for myositis specific antibodies. Muscle biopsy is no longer routinely recommended when the antibodies are typical, unless the form of IIM issometimes difficult to classify.

Treatment

To date scores immunosuppressive and immunomodulatory therapeutic agents are available for the treatment of myositis. Glucocorticosteroids and immunosuppressants remain first-line therapy in many cases with early start and sufficient dosing potentially leading to stabilization of the disease, improvement of strength and decrease in inflammation. Unfortunately the side effects of immunosuppressive treatment may be undesirable. New therapeutic approaches targeting specific immunological pathways are show great promise.

Physiotherapy

Exercise therapy leads to a stabilization of disease progression, with evidence in the literature supporting moderate physical exercise in patients with myositis.

• Research has shown that an exercise programs at home improve muscle strength and endurance.
• Concentric sport activities are appropriate as they cause less injury to muscle fibers than eccentric exercise. Stretching that happens in eccentric sport exercise may cause myalgia, elevated inflammatory response, and an increase of Creatine kinase (CK). CK is an enzyme present in skeletal muscle, heart muscle and brain. When any of these tissues are damaged CK gets into the bloodstream. raised CK levels may indicate muscle injury or disease.
• Aerobic training, for example cycling and resistance exercise over 12 weeks, three times per week, results in an improvement in muscle strength, and does not lead to a significant rise in CK levels post training. The evidence in the literature clearly supports moderate physical exercise in patients with myositis.

Resources

This video made by the The Myositis Association is one of several this site has and is very useful for physiotherapists to watch.

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