A clinical case definition has been developed by an expert medical consensus panel of treating physicians, teaching faculty and world leaders in the research of ME/CFS. The definition provides a flexible conceptual framework that more adequately reflects the complexity of symptoms of a given patient's pathogenesis and should establish ME/CFS as a distinct medical entity and help distinguish it from overlapping medical conditions in the absence of a definitive laboratory test.
Most countries have been using the American Centers of Disease Control (CDC) definition, which was designed to standardize research. However, there has been a growing demand for diagnostic criteria designed for a clinical setting. In response to a survey by the National ME/FM Action Network, doctors across Canada overwhelmingly concurred that a clinical definition, along with diagnostic and treatment guidelines, would be the most helpful items in diagnosing and treating ME/CFS patients. This led to Health Canada selecting an expert consensus panel and establishing their Terms of Reference.
The panel s clinical case definition determines that more of the prominent symptoms are compulsory and symptoms that share a common region of pathogenesis are grouped together for clarity. In addition to severe prolonged fatigue, the definition includes the hallmark symptoms of post-exertional malaise and/or fatigue, sleep dysfunction, pain, two or more of the given neurological/cognitive manifestations, and at least one of the given symptoms from two of the categories of autonomic, neuroendocrine, and immune manifestations. The consensus document also includes a discussion of prominent symptoms, clinical practice diagnostic and treatment guidelines based on the best available research evidence, and an overview of available research on ME/CFS.
The clinical definition will enable clinicians to make an early diagnosis which may assist in lessening the impact of ME/CFS in some patients, said Dr. Bruce M. Carruthers, lead author of the definition. It will reduce the expensive problem of patients being sent to many specialists before being diagnosed and will allow patients to receive appropriate treatments in a timely fashion.
ME/CFS is a severe illness that can be debilitating. There is no known cure. It often begins with a viral type infection such as an acute respiratory or flu-like illness. But instead of recovering, the person's health deteriorates and many other symptoms appear. A number of viruses have been studied but so far there is no conclusive support for any one pathogen causing the illness. Numerous studies have confirmed that there is a biochemical breakdown of one of the body s defense pathways used to fight viruses, which supports the theory that ME/CFS is triggered by an infection. According to a large American study by Dr. Leonard Jason, approximately 422 per 100,000 people (approximately 150,000 Canadians) suffer from ME/CFS compared to 26 per 100,000 women who have breast cancer.
Haworth Press, Inc. has just published the expert consensus document in a special issue of the Journal of Chronic Fatigue Syndrome. To view the clinical definition and for information on how to order the consensus document, go to the website of the National ME/FM Action Network.
Contact numbers for other consensus panel members will be provided upon request.
The National ME/FM Action Network is a Canadian incorporated non-profit organization which advances the recognition and understanding of ME/CFS and fibromyalgia through education, advocacy, support, research and by the publishing of a bi-monthly newsletter 'QUEST'.
* Dr. Bruce M. Carruthers, lead author of the consensus document; co-author of the draft of the original version of the ME/CFS clinical definition, diagnostic and treatment protocols document; internal medicine, Galiano, British Columbia
* Dr. Anil Kumar Jain, co-author of the draft the original version of the ME/CFS consensus document, affiliate of Ottawa Hospital, Ontario
* Dr. Kenny L. De Meirleir, Professor Physiology and Medicine, Vrije Universiteit Brussel, Brussels, Belgium; ME/CFS researcher and clinician; organizer of the World Congress on Chronic Fatigue Syndrome and Related Disorders; a board member of the American Association for Chronic Fatigue Syndrome; co-editor of Chronic Fatigue Syndrome: Critical Reviews and Clinical Advances, and co-editor of Chronic Fatigue Syndrome: A Biological Approach
* Dr. Daniel L. Peterson, affiliate of the Sierra Internal Medicine Associates in Incline Village, Nevada; ME/CFS researcher and clinician; a board member of the American Association for Chronic Fatigue Syndrome; and member of the International Chronic Fatigue Syndrome Study Group
* Dr. Nancy G. Klimas, Clinical Professor of Medicine in Microbiology/Immunology/Allergy and Psychology, University of Miami School of Medicine; ME/CFS researcher and clinician; a board member of the American Association for Chronic Fatigue Syndrome; and member of the federal CFS Coordinating Committee
* Dr. A. Martin Lerner, staff physician at William Beaumont Hospital in Royal Oak, Michigan; Clinical professor and former chief of the Division of Infectious Diseases at Wayne State University s School of Medicine; and ME/CFS researcher and clinician
* Dr. Alison C. Bested, haematological pathologist; former head of the Division of Haematology and Immunology at the Toronto East General and Orthopaedic Hospital; affiliate of the Environmental Health Clinic and Sunnybrook & Women s College Health Sciences Centre, Toronto, Ontario; ME/CFS researcher and clinician
* Dr. Pierre Flor-Henry, Clinical Professor of Psychiatry, University of Alberta; Clinical Director of General Psychiatry and Director of the Clinical Diagnostic and Research Centre, both based at Alberta Hospital in Edmonton, Alberta, Canada; ME/CFS brain researcher
* Dr. Pradip Joshi, internal medicine, Clinical Associate Professor of Medicine at Memorial University of Newfoundland in St. John s, Canada
* Dr. A. C. Peter Powles, Professor Emeritus, Faculty of Health Science, McMasters University, Hamilton; Professor, Faculty of Medicine, University of Toronto; Chief of Medicine and Sleep Disorders Consultant, St. Joseph's Health Centre, Toronto; Sleep Disorder Consultant at the Sleep Disorder Clinic at St. Joseph s Healthcare, Hamilton, and Central West Sleep Affiliation, Paris, Ontario
* Dr. Jeffrey A. Sherkey, family medicine, affiliate of the University Health Network, Toronto, Ontario; and diagnosed with chronic fatigue syndrome nearly 10 years ago
* Marjorie I. van de Sande, Consensus Coordinator; and Director of Education for the National ME/FM Action Network, Canada