Polymyositis

Welcome to PT 635 Pathophysiology of Complex Patient Problems This is a wiki created by and for the students in the School of Physical Therapy at Bellarmine University in Louisville KY. Please do not edit unless you are involved in this project, but please come back in the near future to check out new information!!

Original Editors - Chris Pyles & Kayla Thiesen from Bellarmine University's Pathophysiology of Complex Patient Problems project.

Lead Editors - Your name will be added here if you are a lead editor on this page.  Read more.

Definition/Description^1,2

Polymyositis (PM) is a chronic inflammatory myopathy, which is classified as a persistence inflammatory muscle disease. PM affects striated muscle fibers, but spares smooth muscle throughout the body and can come on gradually over weeks or months. PM targets proximal musculature, with little to no pain, impairing strength and is characterized by an elevation of serum muscle enzymes and a wide variety of skin abnormalities, sometimes including cardiopulmonary impairments. Although no pain is present, some tenderness may occur directly over involved musculature, but all deep tendon reflexes are preserved. The general approach to treating polymyositis is through pharmacological and conservative treatment to increase strength and prevent development of extra-muscular disease in order to better outcomes for the patient.

Prevalence²

Current literature is unclear about the age of presentation – some articles state it mostly affects adults in their 30’s to 50’s, while other sources say the onset is in adults aged 50-70. Although research shows that it is rare to have an onset earlier than 18 years of age, it has been proven that females are more susceptible to PM than males with a ratio of 2:1. One in 100,000 people have PM with blacks more commonly diagnosed than whites.

Characteristics/Clinical Presentation^1,2

Symptoms are symmetrical and can gradually appear or may fluctuate within short or long periods of time. Functionally, patients may have issues with grabbing a glass off of a high shelf, climbing stairs, or getting up or sitting down on a couch.

With progression of the disease, neck and shoulder girdle musculature can be involved resulting in minimal muscle contraction or paralysis.

Here is a summary of the signs and symptoms

• Proximal muscle weakness
• Difficult swallowing (dysphagia)
• Difficulty speaking
•  Mild joint or muscle tenderness
• Fatigue
• Arthralagia
• Shortness of breathe
• Malnutrition
• Weight loss
• Calcium deposits
• Morning stiffness

As PM progresses, it can affect the upper esophagus as well as striated muscle fibers in the chest wall. As a result, patients can have more complex signs and symptoms such as:

• Aspiration pneumonia
• Respiratory failure
• Variety of cardiovascular complications (i.e. CHF, arrhythmias)
• Interstitial lung disease
  
  

Associated Co-morbidities^1,2,3,4

Since Polymyositis is a autoimmune disease, it is often associated with other autoimmune dieases and infectious disorders:

• Connective tissue diseases: lupus, RA, scleroderma, Sjogrens
• Cardiovascular disease: myocarditis, CHF, heart arrhythmias
• Lung disease: interstitial lung disease
• HIV/AIDS
• Raynauds Phenomenon

Medications¹

Earlier treatment is always better – your doctor will decide based on your symptoms what treatment will be more tailored to you. There have not been very many scientific studies which effects insurance coverage and you should be closely monitored for adverse side effects:

• Corticosteroids
• Immunosupressive therapies (If cortico-steroids aren’t working)
  1. Corticosteroid sparing agents (Azasan, Imuran, Trexall, Methotrexate, Rheumatrex).
  2. Intravenous immunoglobulin (IVIG).
  3. Tacrolimus (Prograf)
  4. Cyclophosphamide (Cytoxan)
  5. Cyclosporine (Gengraf, Neoral, Sandimmune)
• Biological therapies (Severe Cases, only if the above two didn’t work)
  1. Rituximab (Rituxan)
  2. Tumor necrosis factor (TNF) inhibitors (Enbrel, Remicade)

Diagnostic Tests/Lab Tests/Lab Values¹

There are several different diagnostic tools to determine if a patient has polymyositis, it can be a long process and both health care providers as well as patients are encouraged to remain patient:

• Magnetic Resonance imaging (MRI)
• Electromyography
• Muscle Biopsy (looking for inflammation, damage, or infection/abdnormal proteins and enzyme deficiencies)
• Blood Tests:
  1. Increased Creatine Kinase
  2. Increased Aldolase
  
  

Etiology/Causes

add text here

Systemic Involvement

add text here

Medical Management (current best evidence)

add text here

Physical Therapy Management (current best evidence)

add text here

Alternative/Holistic Management (current best evidence)

add text here

Differential Diagnosis

add text here

Case Reports/ Case Studies

add links to case studies here (case studies should be added on new pages using the case study template)

Resources

add appropriate resources here

Recent Related Research (from Pubmed)

see tutorial on Adding PubMed Feed

Failed to load RSS feed from http://eutils.ncbi.nlm.nih.gov/entrez/eutils/erss.cgi?rss_guid=1NGmwZeh8JwVIzrKgHG1LrDm0izTr7ViJiDkSYAY2BW5hiXsx0|charset=UTF-8|short|max=10: Error parsing XML for RSS

References

see adding references tutorial.