Myalgic encephalomyelitis/chronic fatigue syndrome

The cause of chronic fatigue syndrome is not known. Some researchers have proposed that this condition is caused by viral infections or by immunological, hormonal or psychiatric problems. However, none of these possible explanations are proven. It is also believed that there may be a genetic predisposition for this condition and stress-related events act as triggers.

The Committee on the Diagnostic Criteria for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, The Board of Select Populations and the Institute of Medicine proposed diagnostic criteria which requires that the patient have the following three symptoms:

1. Chronic fatigue that interferes with daily activities and work, which is often profound, is of new or definite onset (not lifelong), is not the result of excessive exertion or other medical conditions, and is not greatly alleviated by rest.
2. Post-exertional malaise.
3. Unrefreshing sleep.

At least one of the two following symptoms is also required:

• Cognitive impairment (impairment of short memory or concentration).
• Orthostatic intolerance (Onset of symptoms when standing upright that are improved by lying back down).

Other symptoms include post exertion illness lasting more than 24 hours, muscle pain, pain in the joints, headaches, tender lymph nodes and sore throat.

These symptoms should have persisted or recurred during 6 or more consecutive months of illness and they cannot have first appeared before the fatigue.

The diagnosis can only be made after 6 months because many other causes of similar fatigue do not last beyond 6 months. The patients should be asked questions about the frequency and severity of their symptoms. Questionnaires or clinical observations that may help the diagnosis should also be used, such as the Wood Mental Fatigue Inventory.

The following tests, together with the symptoms, support the diagnosis of CFS (these tests are not routinely required, nor do negative results rule out the diagnosis):

• Two cardiopulmonary exercise tests (CPETs) separated by 24 hours that show inability to repeat the same maximal or anaerobic threshold measures on the second day; this mean that the values on the second CPET must be much lower than those on the first CPET (note that this test may worsen symptoms in these patients).
• Standing test or tilt test to evaluate for postural tachycardia syndrome, neurally mediated hypotension, and orthostatic hypotension.

Sleep studies do not seem to help to the diagnosis of this disorder. Neurological or psychological testing is not required for diagnosis.

Other symptoms and testing that may support the diagnosis of CFS may include:

• History of past infection from which patient never fully recovered with or without blood exams that show the presence of virus-specific immunoglobulin M (IgM), near the onset of illness.
• History of having repeated infections with or without exams showing an abnormal immune function, such as decreased function of natural killer cells in those with severe disease.

Many patients with CFS have other disorders as well, some of which—including fibromyalgia, irritable bowel syndrome, metabolic syndrome, sleep disorders, and depression—may have symptoms that overlap with those of CFS. The diagnosis and treatment of these conditions is necessary when caring for patients.

Chronic fatigue syndrome, also known as systemic exertion intolerance disease, is a condition that causes extreme, long-lasting fatigue which can limit the ability to participate in ordinary, daily activities. It generally occurs in young adults (20 to 40 years of age) and is twice as common in women. The main symptom is disabling fatigue that does not improve with rest. Other signs and symptoms may include muscle pain, joint pain, concentration and memory problems, headaches, sleep problems, fever, sore throat, and/or tender lymph nodes. The exact cause is not known. There is still no cure or effective treatment for this condition but there are several clinical trials.

There is debate in the medical literature about the relationship between myalgic encephalomyelitis and chronic fatigue syndrome. There is no consensus on nomenclature or classification for these disorders. Different countries, organizations, and researchers continue to use different names to describe these conditions.

The U.S. National Institutes of Health, through the National Library of Medicine, developed ClinicalTrials.gov to provide patients, family members, and members of the public with current information on clinical research studies. Currently, a number of active, recruiting, or completed clinical trials are listed for chronic fatigue syndrome. To view these trials, go to ClinicalTrials.gov and enter
"chronic fatigue syndrome" as your search term. You can use each study’s contact information to learn more about the ones that interest you. This site may be checked often, as it is regularly updated.

You can also find relevant articles about treatment for chronic fatigue syndrome through PubMed, a searchable database of biomedical journal articles. Although not all of the articles are available for free online, most articles listed in PubMed have a summary available. To obtain the full article, contact a medical/university library or your local library for interlibrary loan. You can also order articles online through the publisher’s Web site. Using "chronic fatigue syndrome treatment" as your search term should help you locate articles. View a sample search of articles about treatment for chronic fatigue syndrome here.

The National Library of Medicine (NLM) Web site has a page for locating libraries in your area that can provide direct access to these journals (print or online). The Web page also describes how you can get these articles through interlibrary loan and Loansome Doc (an NLM document-ordering service). You can access this page at the following link http://nnlm.gov/members/. You can also contact the NLM toll-free at 888-346-3656 to locate libraries in your area.

At this time the underlying cause for chronic fatigue syndrome is unknown, also the symptoms and condition severity is highly variable among patients. As a result it is a challange to create a single pallitative care guideline that can be applied with successful results to all. Instead, a person with chronic fatigue syndrome should talk to their doctor about the symptoms that are most disruptive or disabling to them, so that their doctor can tailor their management plan accordingly. Treatment of chronic fatigue syndrome can be directed toward the most problematic symptoms as prioritized by the patient, but only after underlying conditions applicable to those symptoms have been investigated and excluded.

We are not aware of standardized staging criteria for chronic fatigue syndrome. Just as the symptoms and severity of this syndrome vary, so does its clinical course. The percentage of people who completely recover from chronic fatigue syndrome is not known, however most people have improvement in their symptoms over time with proper treatment strategies and regular care. People with chronic fatigue syndrome may cycle through periods of relief and periods of illness.

Treatment options for chronic fatigue syndrome (CFS) are limited. Treatment is largely supportive and is focused on the specific symptoms present in each individual.

Medications, special diets, vitamin supplements, behavioral therapies, and exercise therapies have been evaluated as treatments for CFS, but none have been proven effective. Several clinical trials aiming to find effective treatments are currently ongoing.

Other disorders that may be present, such as fibromyalgia, irritable bowel syndrome, metabolic syndrome, sleep disorders, and depression should be treated when caring for patients.