ME (Ramsay) and ME-International Case Criteria (ME-ICC): two distinct clinical entities

Excerpt:

The review of the differences and similarities in the different case definitions for myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) by Lim and Son [1] deserves appreciation. Based on their analysis the authors acknowledge the “distinct view of ME and CFS” [2] and recognize four categories of case definitions: ME, ME/CFS, CFS [3] and Systemic Exertion Intolerance Disorder (SEID) [4].

Indeed these labels reflect very different case definitions [5]. According to Lim and Son [1] the first category comprises two ‘ME’ case definitions: ME (Ramsay) [6] and ME according to the International Case Criteria (ME-ICC) [7]. However as can be deduced from Table 2 [1], ME [6] and ME-ICC [7] are two distinct clinical entities [8].

Source: Twisk FNM. ME (Ramsay) and ME-International Case Criteria (ME-ICC): two distinct clinical entities. J Transl Med. 2020 Nov 25;18(1):447. doi: 10.1186/s12967-020-02617-0. PMID: 33239008. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-020-02617-0 (Full text)

Myalgic Encephalomyelitis, Chronic Fatigue Syndrome, and Chronic Fatigue: Three Distinct Entities Requiring Complete Different Approaches

Abstract:

PURPOSE OF REVIEW: A recent review implicates that myalgic encephalomyelitis (ME), chronic fatigue syndrome (CFS), and chronic fatigue are part of the “fatigue spectrum” and recommends “longitudinal studies integrating biopsychosocial approaches to inform early management and targeted rehabilitation strategies.”

RECENT FINDINGS: ME is a neuromuscular disease distinguished by muscle fatigability (prolonged muscle weakness after minor exertion) and specific signs of neurological dysfunction. ME is not equivalent to CFS, as proposed by the authors. CFS is defined as unexplained chronic fatigue accompanied by at least four out of a list of eight specific symptoms. CFS is a distinct clinical entity and not merely a severe variant of CF, as suggested. Proof that CF, CFS, and ME are part of a “fatigue continuum” and that CF can convert to CFS at a later stage is lacking. Biopsychosocial approaches for early management and rehabilitation of CF, as promoted by the authors, are at odds with the current understandings of ME, CFS, and CF. The (bio)psychosocial explanatory models for ME and CFS have proven to be invalid, and the associated interventions, cognitive behavioral therapy and graded exercise therapy, have shown to be ineffective and even potentially harmful. ME, CFS, and CF are three very distinct clinical entities. Interventions justified by (bio)psychosocial models appear to be unsuccessful and potentially noxious. To develop effective treatments, it is crucial to make a clear distinction between ME, CFS, and CF and to leave the (bio)psychosocial explanations and therapies behind us.

Source: Twisk FNM. Myalgic Encephalomyelitis, Chronic Fatigue Syndrome, and Chronic Fatigue: Three Distinct Entities Requiring Complete Different Approaches. Curr Rheumatol Rep. 2019 May 9;21(6):27. doi: 10.1007/s11926-019-0823-z. https://www.ncbi.nlm.nih.gov/pubmed/31073713

Myalgic Encephalomyelitis or What? The International Consensus Criteria

Abstract:

Myalgic encephalomyelitis (ME) is a neuromuscular disease with two distinctive types of symptoms (muscle fatigability or prolonged muscle weakness after minor exertion and symptoms related to neurological disturbance, especially of sensory, cognitive, and autonomic functions) and variable involvement of other bodily systems. Chronic fatigue syndrome (CFS), introduced in 1988 and re-specified in 1994, is defined as (unexplained) chronic fatigue accompanied by at least four out of eight listed (ill-defined) symptoms. Although ME and CFS are two distinct clinical entities (with partial overlap), CFS overshadowed ME for decades.

In 2011, a panel of experts recommended abandoning the label CFS and its definition and proposed a new definition of ME: the International Consensus Criteria for ME (ME-ICC). In addition to post-exertional neuroimmune exhaustion (PENE), a mandatory feature, a patient must experience at least three symptoms related to neurological impairments; at least three symptoms related to immune, gastro-intestinal, and genitourinary impairments; and at least one symptom related to energy production or transportation impairments to meet the diagnosis of ME-ICC.

A comparison between the original definition of ME and the ME-ICC shows that there are some crucial differences between ME and ME-ICC. Muscle fatigability, or long-lasting post-exertional muscle weakness, is the hallmark feature of ME, while this symptom is facultative for the diagnosis under the ME-ICC. PENE, an abstract notion that is very different from post-exertional muscle weakness, is the hallmark feature of the ME-ICC but is not required for the diagnosis of ME. The diagnosis of ME requires only two type of symptoms (post-exertional muscle weakness and neurological dysfunction), but a patient has to experience at least eight symptoms to meet the diagnosis according to the ME-ICC. Autonomic, sensory, and cognitive dysfunction, mandatory for the diagnosis of ME, are not compulsory to meet the ME-ICC subcriteria for ‘neurological impairments’.

In conclusion, the diagnostic criteria for ME and of the ME-ICC define two different patient groups. Thus, the definitions of ME and ME-ICC are not interchangeable.

Source: Twisk, F. Myalgic Encephalomyelitis or What? The International Consensus Criteria. Diagnostics 2019, 9, 1. https://www.mdpi.com/2075-4418/9/1/1/htm (Full article)

Myalgic Encephalomyelitis (ME) or What? An Operational Definition

Abstract:

Myalgic encephalomyelitis (ME), identified as a new clinical entity with distinctive features in 1956, was originally considered as a neuromuscular disease. In 1988 the Centers for Disease Control and Prevention introduced the ill-defined concept of chronic fatigue syndrome (CFS). As predicted, CFS, unjustly considered to be a synonym for ME, pushed ME to the background. To develop effective therapies for of ME and CFS, it is essential to investigate patients with ME specifically. For that reason, an operational definition of ME is indispensable. This article proposes an operational definition based on the most recent formal definitions and symptoms observed in ME. ME is a multi-systemic illness, which

(1) often has a sudden onset, in most cases a respiratory and/or gastro-intestinal infection, but a gradual or more dramatic onset is also possible;

(2) has an epidemic and an endemic form;

(3) has an unique clinical pattern deviating from other post-viral states;

(4) is distinguished by muscle fatigability/prolonged muscle weakness after trivial exertion;

(5) is accompanied by symptoms relating to neurological disturbance, especially of cognitive, autonomic, and sensory functions;

(6) can be accompanied by symptoms associated with cardiac and other systems;

(7) is characterized by fluctuation of symptoms (within and between “episodes”);

(8) has a prolonged relapsing course; and

(9) has a tendency to become chronic.

In conclusion, a discriminative definition for ME contains four mandatory elements:

(1) muscle fatigability/post-exertional muscle weakness lasting for days;

(2) operational criteria for “neurological disturbance, especially of cognitive, autonomic and sensory functions”;

(3) fluctuation of symptoms; and

(4) a prolonged relapsing course. This tentative definition of ME justifies the qualification “neuromuscular disease”.

Source: Twisk F. Myalgic Encephalomyelitis (ME) or What? An Operational Definition. Diagnostics (Basel). 2018 Sep 8;8(3). pii: E64. doi: 10.3390/diagnostics8030064. http://www.mdpi.com/2075-4418/8/3/64 (Full study)

Dutch Health Council Advisory Report on Myalgic Encephalomyelitis and Chronic Fatigue Syndrome: Taking the Wrong Turn

Abstract:

Recently, the Dutch Health Council published their advisory report on Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS) which is meant to determine the medical policy with regard to ME in the Netherlands. The Health Council briefly discusses several diagnostic criteria and proposes to use new diagnostic criteria for “ME/CFS” in research and clinical practice in the future. The advisory report then summarizes organic abnormalities observed in the last decades and concludes that “ME/CFS” is a “serious, chronic, multisystem disease”.

According to the Health Council there are no curative treatments for “ME/CFS”, due to lack of knowledge, but specific medication could bring symptomatic relief. The Health Council recommends conducting more research, to (re)educate medical professionals about “ME/CFS”, to appoint three academic expertise centres, which will install a care network for patients, and to fairly judge the limitations (disability) of patients when they apply for a disability income, medical aid and care. The advisory report was welcomed by many patients, because it puts an end to the dominance of the (bio)psychosocial explanatory model and seems to offer a perspective of improving the situation of patients. However, the starting point of the advisory report, a new definition of “ME/CFS”, will have serious (long-lasting) consequences for patients and researchers.

Source: Twisk F. Dutch Health Council Advisory Report on Myalgic Encephalomyelitis and Chronic Fatigue Syndrome: Taking the Wrong Turn. Diagnostics (Basel). 2018 May 16;8(2). pii: E34. doi: 10.3390/diagnostics8020034. http://www.mdpi.com/2075-4418/8/2/34 (Full article)

An analysis of Dutch hallmark studies confirms the outcome of the PACE trial: cognitive behaviour therapy with a graded activity protocol is not effective for chronic fatigue syndrome and Myalgic Encephalomyelitis

Abstract:

Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS) are considered to be enigmatic diseases. Several studies propose that the combination of cognitive behaviour therapy with a graded activity protocol (CBT+), justified by a so-called (bio)psychosocial (explanatory) model, is an effective treatment option for CFS (ME).

Objective :A critical review of five Dutch hallmark studies that allegedly support this claim.

Methods: An analysis of the five CBT+ studies with special attention to the patients studied, the criteria (subjective and objective measures and cut-off scores) used to select participants and to define improvement and recovery, the consistency of the definitions of caseness (being diagnosed as a CFS patient at entry) versus the definitions of improvement and recovery after CBT+, and the objective effects.

Results: The studies investigated suffer from various methodological flaws. Apart from these methodological shortcomings, the claim that CBT+ is an effective treatment option for CFS is not substantiated by the data reported. Some studies investigated CFS patients, other studies investigated CF patients, labelled as CFS patients, or combinations of CFS and CF patients. No study investigated the effect of CBT+ in a group of patients meeting the (original) diagnostic criteria for ME. The effects of CBT+ on subjective measures, for example fatigue and disability, if present, are insufficient to achieve normal values. Impressive recovery and improvement rates are based on very loose criteria for subjective measures. Cut-off scores for subjective measures used to define improvement and recovery in studies show overlap with cut-off scores for CFS caseness in one or more of the other studies. More importantly, looking at the objective measures, the proof of clinical improvement after CBT+ is lacking.

Conclusion: Solid evidence of effectiveness of CBT+ for CFS, let alone ME, is lacking in the five hallmark studies. The lack of objective improvement indicates CBT+ is ineffective. This finding confirms the outcome of the large-scale PACE-trial in the UK.

Source: Twisk FNM (2017) An analysis of Dutch hallmark studies confirms the outcome of the PACE trial: cognitive behaviour therapy with a graded activity protocol is not effective for chronic fatigue syndrome and Myalgic Encephalomyelitis. Gen Med Open, 2017 doi: 10.15761/GMO.1000117 (Full article)

Studies and surveys implicate potential iatrogenic harm of cognitive behavioral therapy and graded exercise therapy for myalgic encephalomyelitis and chronic fatigue syndrome patients

Abstract:

Cognitive behavorial therapy (CBT) and graded exercise therapy (GET) are declared to be effective and safe therapies for Myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS). Medical policies in various countries, e.g. the UK and the Netherlands, recommend CBT and GET as evidence-based treatments. But studies and patient surveys in several countries indicate that CBT often has no effect at all and that GET has detrimental effects in a large subgroup of patients.

Editorial

ME is a disease characterized by distinctive muscular symptoms, including muscle weakness and myalgia after minor exertion lasting for days, neurological symptoms implicating cerebral dysfunction, symptoms indicating circulatory impairment and other symptoms [1,2]. CFS is primarily defined by (unexplained) chronic fatigue, which must be accompanied by at least four out of eight ‘additional’’ symptoms [3]. ME and CFS are incorrectly conceived as ‘similar disorders’ [4]. But the case criteria define three patient groups: ME and/or CFS patients [5], labeled as ME/CFS patients within this context.

Cognitive behavioral therapy (CBT) and graded exercise therapy (GET) are declared to be effective [6,7] and safe [7,8] therapies for Myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS). Medical policies in various countries, e.g. the UK [9] and the Netherlands [10], recommend CBT and GET as evidence-based treatments.

However various studies implicate that CBT, GET and other behavioral interventions, including graded activity, have negative effects on (subgroups of) ME/CFS patients.

Núñez and co-workers [11] observed that adding CBT and GET to pharmacological treatment had a negative effect on SF-36 physical functioning and pain scores. Jason and others [12,13] found that ‘non-pharmacologic therapies’ had a negative effect on the mean SF- 36 physical functioning score (changes from 5 to -35) of a large subgroup of CFS patients, with lymphocyte subsets data suggesting an elevated humoral immune response (Th2/B Cell). Although ‘Guided graded Exercise Self-help’ (GET) was qualified as “a moderately effective and safe intervention” [14], the investigators acknowledged that a patient subgroup had deteriorated after the GET trial, possibly due to “a worse exacerbation of symptoms in response to GET” [15].

In various surveys [16-18] most ME/CFS patients experienced no improvement after CBT and more than half of the patients reported GET made them worse. A detailed analysis [18] of a large-scale patient survey in the UK [19] shows that, when combinations of therapies are excluded, 73% of the patients they stayed the same after CBT, while 8% of the patients improved and 18% got worse. No less than 74% of the patients reported worsening of their symptoms after GET, 14% of the patients experienced no change and only 12% reported improvement after GET. In a recent patient survey in the Netherlands [20] 11% reported CBT had improved their health situation, 36% experienced no change, and 53% reported CBT had worsened their condition. 63% reported GET had made their symptoms (much) worse and 34% reported no change. Only 3% of the patients experienced improvement after GET. One could argue that patient surveys (through the internet) are potentially prone to many biases, but a study [21] found that ‘’unsolicited’ web-based patient ratings of care correlate well with conventional research findings, i.e. formal measurements.

As affirmed by the medical authorities in the US recently, “ME/CFS is a serious, chronic, complex, multisystem disease” [4] with “strong evidence” indicating that “immunologic and inflammatory pathologic conditions, neurotransmitter signaling disruption, microbiome perturbation, and metabolic or mitochondrial abnormalities are potentially important for the definition and treatment of ME/CFS [22]. Exertion has (prolonged) negative effects in ME/CFS [4]. For that reason studies and surveys indicating potential harm of CBT and GET in large subgroups of ME/CFS patients should be taken seriously. The ‘safety claim’ is at odds with several observations.

References

  1. Dowsett EG, Ramsay AM, McCartney RA, et al. Myalgic Encephalomyelitis – a persistent enteroviral infection? Postgrad. Med. J.66(777), 526-530 (1990).

  2. Ramsay AM, Dowsett EG, Myalgic Encephalomyelitis: Then and now. In Hyde BM, Goldstein J, Levine P, editors. The Clinical and Scientific Basis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Ottawa: The Nightingale Research Foundation pp. 81-84 (1992).

  3. Fukuda K, Straus SE, Hickie I, et al. The chronic fatigue syndrome: a comprehen­sive approach to its definition and study. Ann. Intern. Med. 121(12), 953-959 (1994).

  4. Institute of Medicine. Beyond Myalgic Encephalomyelitis/chronic fatigue syn­drome: redefining an illness. Washington, (2015).

  5. Twisk FNM. Replacing Myalgic Encephalomyelitis and chronic fatigue syndrome with Systemic Exercise Intolerance Disease is not the way forward. Diagnostics (Basel). 6(1), 10 (2016).

  6. Malouff JM, Thorsteinsson EB, Rooke SE, et al. Efficacy of cognitive behavioral therapy for chronic fatigue syndrome: a meta-analysis. Clin. Psychol. Rev. 28(5), 736-745 (2008).

  7. Larun L, Brurberg KG, Odgaard-Jensen J, et al. Exercise therapy for chronic fatigue syndrome. Cochrane Database Syst Rev. 4, CD003200 (2017).

  8. Bleijenberg G, Knoop H. Chronic fatigue syndrome: where to PACE from here? Lancet. 377(9768), 786-788 (2011)

  9. National Institute for Health and Clinical Excellence. Chronic fatigue syndrome/ myalgic encephalomyelitis (or encephalopathy): diagnosis and management of chronic fatigue syndrome/myalgic encephalomyelitis (or encephalopathy) in adults and children. London (UK), (2007).

  10. CBO. Richtlijn diagnose, behandeling, begeleiding en beoordeling van patiënten met het chronisch vermoeidheidssyndroom (CVS). Utrecht (NL), (2013).

  11. Núñez M, Fernández-Solà J, Nuñez E, et al. Health-related quality of life in patients with chronic fatigue syndrome: group cognitive behavioural therapy and graded exercise versus usual treatment. A randomised controlled trial with 1 year of follow-up. Clin. Rheumatol. 30(3), 381-389 (2011).

  12. Jason LA, Torres-Harding S, Friedberg F, et al. Non-pharmacologic interventions for CFS: a randomized trial. J. Clin. Psychol. Med. Settings. 14(4), 275-296 (2007).

  13. Jason LA, Torres-Harding S, Brown M, et al. Predictors of change following participation in non-pharmacologic interventions for CFS. Trop. Med. Health. 36(1), 23-32 (2008).

  14. Clark LV, McCrone P, Ridge D, et al. Graded Exercise Therapy guided Self-hElp Treatment (GETSET) for patients with chronic fatigue syndrome: a randomised controlled trial in secondary care. J. Psychosom. Res. 5(2), 59-60 (2016).

  15. Cheshire A, Ridge D, Clark L, et al. Why patients with chronic fatigue syndrome/ Myalgic Encephalomyelitis improve or deteriorate with graded exercise therapy. J. Psychosom. Res. 85, 59 (2016).

  16. Kirke KD. PACE investigators’ response is misleading regarding patient survey results. J. Health. Psych. 22(9), 1168-1176 (2017).

  17. Twisk FNM, Maes M. A review on cognitive behavorial therapy (CBT) and graded exercise therapy (GET) in myalgic encephalomyelitis (ME) / chronic fatigue syndrome (CFS): CBT/GET is not only ineffective and not evidence-based, but also potentially harmful for many patients. Neuro. Endocrinol. Lett. 30(3), 284-299 (2009).

  18. Geraghty K, Hann M, Kurtev S. Myalgic encephalomyelitis/chronic fatigue syndrome patients’ reports of symptom changes following cognitive behavioural therapy, graded exercise therapy and pacing treatments: Analysis of a primary survey compared with secondary surveys. J. Health. Psychol. (2017).

  19. ME Association. “No decisions about me without me”. ME/CFS illness management survey results, part 1. Gawcott, Bucks (England), (2015).

  20. De Kimpe A, Crijnen B, Kuijper J, et al. Zorg voor ME – Enquête onder ME-patiënten naar hun ervaringen met de zorg in Nederland (2016).

  21. Greaves F, Pape UJ, King D, et al. Associations between Internet-based patient ratings and conventional surveys of patient experience in the English NHS: an observational study. BMJ. Qual. Saf. 21(7), 600-605 (2012).

  22. Green CR, Cowan P, Elk R, et al. National Institutes of Health pathways to prevention workshop: Advancing the research on Myalgic Encephalomyelitis/ chronic fatigue syndrome. Ann. Intern. Med. 162(12), 860-865 (2015).

Source: Frank N.M. Twisk. Studies and surveys implicate potential iatrogenic harm of cognitive behavioral therapy and graded exercise therapy for myalgic encephalomyelitis and chronic fatigue syndrome patients. Research on Chronic Diseases. http://www.openaccessjournals.com/articles/studies-and-surveys-implicate-potential-iatrogenic-harm-of-cognitive-behavioral-therapy-and-graded-exercise-therapy-for-myalgic-en-12190.html

Replacing Myalgic Encephalomyelitis and Chronic Fatigue Syndrome with Systemic Exercise Intolerance Disease Is Not the Way forward

Abstract:

Myalgic encephalomyelitis (ME), described in the medical literature since 1938, is characterized by distinctive muscular symptoms, neurological symptoms, and signs of circulatory impairment. The only mandatory feature of chronic fatigue syndrome (CFS), introduced in 1988 and redefined in 1994, is chronic fatigue, which should be accompanied by at least four or more out of eight “additional” symptoms.

The use of the abstract, polythetic criteria of CFS, which define a heterogeneous patient population, and self-report has hampered both scientific progress and accurate diagnosis. To resolve the “diagnostic impasse” the Institute of Medicine proposes that a new clinical entity, systemic exercise intolerance disease (SEID), should replace the clinical entities ME and CFS. However, adopting SEID and its defining symptoms, does not resolve methodological and diagnostic issues.

Firstly, a new diagnostic entity cannot replace two distinct, partially overlapping, clinical entities such as ME and CFS. Secondly, due to the nature of the diagnostic criteria, the employment of self-report, and the lack of criteria to exclude patients with other conditions, the SEID criteria seem to select an even more heterogeneous patient population, causing additional diagnostic confusion. This article discusses methodological and diagnostic issues related to SEID and proposes a methodological solution for the current “diagnostic impasse”.

 

Source: Twisk FN. Replacing Myalgic Encephalomyelitis and Chronic Fatigue Syndrome with Systemic Exercise Intolerance Disease Is Not the Way forward. Diagnostics (Basel). 2016 Feb 5;6(1). pii: E10. doi: 10.3390/diagnostics6010010. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808825/ (Full article)

 

Accurate diagnosis of myalgic encephalomyelitis and chronic fatigue syndrome based upon objective test methods for characteristic symptoms

Abstract:

Although myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) are considered to be synonymous, the definitional criteria for ME and CFS define two distinct, partially overlapping, clinical entities. ME, whether defined by the original criteria or by the recently proposed criteria, is not equivalent to CFS, let alone a severe variant of incapacitating chronic fatigue.

Distinctive features of ME are: muscle weakness and easy muscle fatigability, cognitive impairment, circulatory deficits, a marked variability of the symptoms in presence and severity, but above all, post-exertional “malaise”: a (delayed) prolonged aggravation of symptoms after a minor exertion. In contrast, CFS is primarily defined by (unexplained) chronic fatigue, which should be accompanied by four out of a list of 8 symptoms, e.g., headaches.

Due to the subjective nature of several symptoms of ME and CFS, researchers and clinicians have questioned the physiological origin of these symptoms and qualified ME and CFS as functional somatic syndromes. However, various characteristic symptoms, e.g., post-exertional “malaise” and muscle weakness, can be assessed objectively using well-accepted methods, e.g., cardiopulmonary exercise tests and cognitive tests. The objective measures acquired by these methods should be used to accurately diagnose patients, to evaluate the severity and impact of the illness objectively and to assess the positive and negative effects of proposed therapies impartially.

 

Source: Twisk FN. Accurate diagnosis of myalgic encephalomyelitis and chronic fatigue syndrome based upon objective test methods for characteristic symptoms. World J Methodol. 2015 Jun 26;5(2):68-87. doi: 10.5662/wjm.v5.i2.68. ECollection 2015. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4482824/ (Full article)

 

A critical analysis of the proposal of the Institute of Medicine to replace myalgic encephalomyelitis and chronic fatigue syndrome by a new diagnostic entity called systemic exertion intolerance disease

Abstract:

The Institute of Medicine (IOM) recently published their report in response to an assignment “to define diagnostic criteria for Myalgic Encephalomyelitis (ME)/chronic fatigue syndrome (CFS), to propose a process for reevaluation of these criteria in the future, and to consider whether a new name for this disease is warranted”.

The basic pre-assumption of the IOM committee for the development of evidence-based diagnostic criteria for ME/CFS was that ME and CFS denote conditions with similar symptoms, hence ME/CFS. The IOM committee recommends: (1) that ME/CFS will be renamed ‘systemic exertion intolerance disease’ (SEID); and that a new code should be assigned to SEID in the International Classification of Diseases (ICD), replacing the existing codes for ME (a neurological disease: G93.3) and CFS (‘signs, symptoms, and abnormal clinical and laboratory findings, not elsewhere classified’: R53.82); (2) that a diagnosis of SEID should be made if the new diagnostic criteria are met; (3) that the Department of Health and Human Services develops a toolkit appropriate for screening and diagnosing patients; and (4) that a multidisciplinary group re-examines the new diagnostic criteria when necessary.

This editorial reviews the working procedure of the IOM and two of the outcomes: the recommendation to introduce a new clinical entity (SEID) and new diagnostic criteria. Based upon the contents of the report, and the arguments of the IOM, a search of PubMed and the archive of the Journal of Chronic Fatigue Syndrome using the search terms ME (and old synonyms) and CFS, and a search of PubMed related to the five core symptoms of SEID was conducted.

Reviewing the working method and the recommendations, it is concluded that the new diagnostic criteria for SEID are based upon important methodological shortcomings and that the introduction of SEID to replace both ME and CFS has several profound negative consequences outweighing the advantages.

 

Source: Twisk FN. A critical analysis of the proposal of the Institute of Medicine to replace myalgic encephalomyelitis and chronic fatigue syndrome by a new diagnostic entity called systemic exertion intolerance disease. Curr Med Res Opin. 2015;31(7):1333-47. doi: 10.1185/03007995.2015.1045472. Epub 2015 May 29. https://www.ncbi.nlm.nih.gov/pubmed/25912615 (Full article)