Chronic fatigue syndrome

Chronic fatigue syndrome (CFS) was a name coined by the Centers for Disease Control (CDC) in response to an outbreak of "chronic flu-like illness" in Incline Village, Lake Tahoe in 1984-1985 and several outbreaks and sporadic cases in the United States during the 1980s.

Prior to Incline Village, chronic fatigue syndrome was known as myalgic encephalomyelitis (ME). The "chronic fatigue syndrome" outbreaks of the 1980s and 1990s were likely ME outbreaks, although they differed in some respects from the 1930s-1960s outbreaks. With the development of the 1991 Oxford criteria and the 1994 Fukuda criteria for CFS, which differed in significant respects from historic descriptions of ME, CFS became a basket diagnosis that included patients with ME along with those suffering from a wide range of undefined or misdiagnosed fatiguing illnesses.

There have been media reports of athletes diagnosed with ME or CFS who have recovered in a relatively short period of time after rest, supplementation, and diet changes,  but may have had overtraining syndrome.

Although a diagnosis of CFS is valid and in the US the Fukuda criteria was used, diagnostic criterion such as SEID (ME/CFS), the Canadian Consensus Criteria (ME/CFS), and International Consensus Criteria (ME) offer a more accurate diagnosis of ME/CFS and ME.

Name controversy
The name "chronic fatigue syndrome" is controversial, as many consider it stigmatizing and focusing on a single symptom, chronic fatigue (CF), and despite the fact that post-exertional malaise is regarded as the hallmark symptom rather than chronic fatigue. For decades, patient advocates have been lobbying the CDC to instead use the name myalgic encephalomyelitis (ME). Most patients and patient organizations prefer the name ME, or the hybrid ME/CFS. The names are often used interchangeably or together (ME/CFS).


 * June 2014, Dr. Nancy Klimas discusses the name controversy in the video ME/CFS Diagnosis and Name.

"Chronic fatigue syndrome (CFS) is a complex and serious illness that is often misunderstood. Experts have noted that the terminology 'chronic fatigue syndrome' can trivialize this illness and stigmatize persons who experience its symptoms (1). The name was coined by a group of clinicians convened by CDC in the late 1980s to develop a research case definition for the illness, which, at the time, was called chronic Epstein-Barr virus syndrome. The name CFS was suggested because of the characteristic persistent fatigue experienced by all those affected and the evidence that acute or reactivated Epstein-Barr virus infection was not associated with many cases (2). However, the fatigue in this illness is striking and quite distinct from the common fatigue everyone experiences. A variety of other names have been used, including myalgic encephalomyelitis (ME), ME/CFS, chronic fatigue immune dysfunction, and most recently, systemic exertion intolerance disease (3). The lack of agreement about nomenclature need not be an impediment for advancing critically needed research and education. The term ME/CFS will be used in this article." The Oxford criteria and Fukuda criteria are used in Australia, South Africa, Canada, and parts of Europe; they use the name CFS. The UK will sometimes use the name chronic fatigue syndrome or CFS/ME although they also use the name ME. The United States CDC now uses the acronym ME/CFS.
 * February 2016, Dr Anthony Komaroff, who was part of the CDC group of clinicians who coined the name chronic fatigue syndrome, said: "I think that was a big mistake because the name, in my opinion, and the opinion of a lot of people, it both trivializes and stigmatizes the illness. It makes it seem unimportant, maybe not even real".
 * December 2016, Unger et al. CDC Grand Rounds: Chronic Fatigue Syndrome - Advancing Research and Clinical Education . abstract notes:
 * Jul 2017, the CDC changed its website for Chronic Fatigue Syndrome to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Disability
[[File:HRQoL-journal.pone.0132421.g003.PNG|alt=Graph comparing the unadjusted quality of life EQ-5D-3L HRQoL score for ME/CFS with other chronic illnesses|thumb|ME/CFS patients have the lowest, unadjusted EQ-5D-3L measured HRQoL (quality of life) of 20 conditions, including multiple sclerosis and stroke. Overall, the same results are found after controlling for gender, age, education, and co-morbidity, including mental illness.

Unadjusted average quality of life in CFS compared to different illnesses. Source: [http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0132421#pone-0132421-g003 PLoS One. 2015; 10(7): e0132421.]]]

Chronic fatigue syndrome is a highly disabling illness, with only around 5% of patients achieving a full recovery. Quality of life, physical and work limitations, and pain are consistently found to be worse in CFS patients than in other chronic illnesses.

Notable studies

 * 2014, Chronic fatigue syndrome: A review (Full Text)

Generally accepted criteria for diagnosing ME/CFS and ME

 * Canadian Consensus Criteria (CCC) A diagnosis of moderate and severe forms of ME/CFS are accurately made using this criterion. Adults can be diagnosed at 6 months while pediatric cases are diagnosed at three months.
 * International Consensus Criteria (ICC)  This criterion will accurately diagnose myalgic encephalomyelitis (ME). There is no requirement that the individual have symptoms for a specified period of time for diagnosis, as opposed to CCC, Fukuda, and SEID, which all require 6 months in adults.
 * Systemic Exertion Intolerance Disease (SEID) ME/CFS (SEID) is accurately diagnosed when the core symptoms are met. The Institute of Medicine report as a whole is a comprehensive review of the medical literature available at time of publication (2015). Adults can be diagnosed at 6 months while pediatric cases are diagnosed at three months.

Learn more

 * Chronic Fatigue Syndrome
 * Chronic Fatigue Versus Chronic Fatigue Syndrome - What's the Difference?
 * 2019, Brain studies show chronic fatigue syndrome and Gulf War illness are distinct conditions