History of chronic fatigue syndrome

Several descriptions of illness resembling those of chronic fatigue syndrome have been reported for at least 200 years.[1]

In the 19th century, neurologist George Miller Beard popularised the concept of neurasthenia, with symptoms including fatigue, anxiety, headache, impotence, neuralgia and depression.[2] This concept remained popular well into the 20th century, eventually coming to be seen as a behavioural rather than physical condition, with a diagnosis that excluded postviral syndromes. Neurasthenia has largely been abandoned as a medical diagnosis.[3] The ICD-10 system of the World Health Organization categorized neurasthenia under (F48 Other neurotic disorders) which specifically excluded chronic fatigue syndrome.[4] The current version of ICD, ICD-11, does not include neurasthenia and “deprecates” its use.

A United States Public Health Service (USPHS) official, Alexander Gilliam, described an illness that resembled poliomyelitis, after interviewing patients and reviewing records of one of several clusters which had occurred in Los Angeles, during 1934.[5] The Los Angeles County Hospital outbreak included all or most of its nurses and doctors.[6] Gilliam called the outbreak "atypical poliomyelitis" and described the symptoms as: rapid muscle weakness, vasomotor instability, clonic twitches and cramps, ataxia, severe pain (usually aggravated by exercise), neck and back stiffness, menstrual disturbance and dominant sensory involvement.

There was a cluster of "encephalitis" cases in 1936, at a convent in Wisconsin, amongst novices and convent candidates. The following year two towns in Switzerland had outbreaks of "abortive poliomyelitis" , and 73 Swiss soldiers were given the same diagnosis in 1939. Outbreaks in Iceland were called "Akureyri disease" or "simulating poliomyelitis" and were later called "Iceland disease."[6] 800 people in Adelaide, Australia became ill during 1949–1951 with a disease "resembling poliomyelitis." Two smaller clusters in the United States during 1950 were diagnosed as "Epidemic neuromyasthenia" and "resembling Iceland disease simulating acute anterior poliomyelitis." Additional outbreaks of poliomyelitis-like "mystery diseases" occurred from the 1950s through the 1980s, in Denmark, the United States, South Africa, and Australia, among others.[6]

Several outbreaks of a polio-resembling illness occurred in Britain in the 1950s.[7] A 1955 outbreak at the Royal Free Hospital Group was later called "Royal Free disease" or "benign myalgic encephalomyelitis".[8][9] After the Royal Free Hospital outbreak, a disorder with similar symptoms was found among the general population and the epidemic form came to be considered the exception. Pathology findings, both in monkeys[10] and in rare human casualties,[11] led to the conclusion that the disorder was caused by inflammation of the brain and the spinal cord, particularly the afferent nerve roots, perhaps with neuroimmune etiology.[12]

In the 1960s and 1970s, chronic fatigue symptoms were often attributed to chronic brucellosis, but typically people were seen as having psychiatric disorders, in particular depression.[6] Epidemic cases of benign myalgic encephalomyelitis were called mass hysteria by psychiatrists McEvedy and Beard in 1970,[13] provoking criticism in letters to the editor of the British Medical Journal by outbreak researchers, attending physicians, and physicians who fell ill.[14][15][16][17][18][19][20][21][22] The psychiatrists were faulted for not adequately investigating the patients they described,[23] and their conclusions have been refuted.[3][24][25] In 1978 a symposium held at the Royal Society of Medicine (RSM) concluded that "epidemic myalgic encephalomyelitis" was a distinct disease entity with a clear organic basis.[26]

The illness gained national attention in the United States when the popular magazine Hippocrates ran a cover story of an epidemic at Lake Tahoe, Nevada, in the mid-1980s.[27] The designation Chronic Epstein–Barr Virus was in use in the U.S.,[28][29] but the magazine used the term "Raggedy Ann Syndrome" to note the fatigue and loss of muscle power patients felt.[30]

Researchers investigating the Lake Tahoe cluster did not find evidence that EBV was involved, and they proposed the name "chronic fatigue syndrome", describing the main symptom of the illness.[31][32] They published the first working case definition for CFS in 1988.[33] Research increased considerably, and more so after the criteria were relaxed in 1994.[34]

In 1990, researchers presented evidence they found DNA sequences very similar to the human HTLV-II retrovirus in some CFS patients, at a conference in Kyoto, Japan.[35][36] Their study was later published in the Proceedings of the National Academy of Sciences.[37] A reporter on Prime Time Live stated the announcement made headlines all over the world. The CDC first ignored their findings,[38] then later conducted a study and published a paper that refuted the hypothesis.[39]

In the United Kingdom, the Chief Medical Officer Kenneth Calman requested a report from the medical Royal Colleges in 1996. This led to the publication of a joint report in which the term "chronic fatigue syndrome" was found to be most representative.[40] This was followed in 2002 by a further report by the new CMO, Liam Donaldson.[41]

The U.S. Centers for Disease Control & Prevention (CDC) recognize CFS as a serious illness, and launched a campaign in June 2006 to raise public and medical awareness about it.[42][43]

A 2009 study published in the journal Science reported an association between a retrovirus xenotropic murine leukemia virus–related virus (XMRV) and CFS. The editors of Science subsequently attached an "Editorial Expression of Concern" to the report, to the effect that the validity of the study "is now seriously in question".[44] and in September 2011, the authors published a "Partial Retraction" of their 2009 findings;[45] this was followed by a full retraction by the magazine's Editor in Chief, after the authors failed to agree on a full retraction statement.[46] Also in September 2011, the Blood XMRV Scientific Research Working Group published a report, which concluded "that currently available XMRV/P-MLV assays, including the assays employed by the three participating laboratories that previously reported positive results on samples from CFS patients and controls (2, 4), cannot reproducibly detect direct virus markers (RNA, DNA, or culture) or specific antibodies in blood samples from subjects previously characterized as XMRV/P-MLV positive (all but one with a diagnosis of CFS) or healthy blood donors."[47] In December 2011, the Proceedings of the National Academy of Sciences published a similar retraction for an August 2010 paper.[48] Some members of the patient community, who had viewed the XMRV findings as a source of hope for a possible cure, initially reacted negatively when the papers were called into question. One UK researcher reported verbal abuse after publishing an early paper indicating that the XMRV studies were flawed.[49]

The World Health Organization's (WHO) International Classification of Diseases (ICD), mandates the international classifications of diseases to allow comparison of health and health fields across countries and throughout the world.[50] Not all terms appear in the tabular list (Volume 1), and many more terms are listed in the alphabetic index (Volume 3) of the ICD.[51]