chronic fatigue syndrome vs myalgic encephalomyelitis – Page 2

Contrasting Chronic Fatigue Syndrome versus Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

BACKGROUND: Much debate is transpiring regarding whether chronic fatigue syndrome (CFS) and myalgic encephalomyelitis (ME) are different illnesses. Several prior studies that compared the Fukuda et al. CFS criteria to the Canadian ME/CFS criteria found that the Canadian criteria identified patients with more functional impairments and greater physical, mental, and cognitive problems than those who met Fukuda et al. criteria.[3,4] These samples were located in the Chicago metropolitan area, so the results could not be generalized to other locations. In addition, past studies used a symptom questionnaire that was not specifically developed to tap the Canadian criteria.

PURPOSE: The present comparative study of CFS and ME/CFS criteria was intended to correct the methodological problems of prior studies.

METHODS: This article used data from three distinct samples to compare patients who met criteria for the ME/CFS Canadian clinical case definition [1] to those who met the Fukuda et al. CFS case definition.[2].

RESULTS: Findings indicated that fewer individuals met the Canadian criteria than the Fukuda et al. criteria. Those who met the Canadian criteria evidenced more severe symptoms and physical functioning impairment.

CONCLUSIONS: Future research should continue to compare existing case definitions and determine which criteria best select for this illness.

Source: Jason LA, Brown A, Evans M, Sunnquist M, Newton JL. Contrasting Chronic Fatigue Syndrome versus Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Fatigue. 2013 Jun 1;1(3):168-183. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3728084/ (Full article)

Case definitions and diagnostic criteria for Myalgic Encephalomyelitis and Chronic fatigue Syndrome: from clinical-consensus to evidence-based case definitions

Abstract:

The symptom spectrum of Myalgic Encephalomyelitis (ME) was first detailed in 1959 and later operationalised into a diagnostic protocol (Melvin Ramsey). In 1988 the Holmes case definition coined the term chronic fatigue syndrome (CFS). Fukuda’s Centers for Disease Control and Prevention criteria are very heterogeneous and comprise patients with milder symptoms than the Holmes case definition. The CDC Empirical Criteria for CFS lack sensitivity and/or specificity. Other CFS definitions, e.g. the Oxford criteria, delineate people with idiopathic fatigue. Some authors make the clinical CFS diagnosis when slightly increased self-rated fatigue scores are present. In 2011, Carruthers’ International Consensus Criteria attempted to restore the focus on selecting people who suffer from ME.

Cognitive bias in criteria construction, patient selection, data collection and interpretation has led to the current state of epistemological chaos with ME, CFS, CFS/ME and ME/CFS, and CF being used interchangeably. Moreover, none of the above mentioned classifications meet statistically based criteria for validation. Diagnostic criteria should be based on statistical methods rather than consensus declarations. Ongoing discussions about which case definition to employ miss the point that the criteria did not pass appropriate external validation.

In 2012, Maes et al. performed pattern recognition methods and concluded that CFS patients (according to Fukuda’s criteria) should be divided into those with CFS or ME, on the basis that people with ME display a worsening of their illness following increases in physical or cognitive activity. Both ME and CFS are complex disorders that share neuro-immune disturbances, which are more severe in ME than in CFS. This paper expands on that strategy and details a range of objective tests, which confirm that a person with ME or CFS has a neuro-immune disease.

By means of pattern recognition methods future research should refine the Maes’ case definitions for ME and CFS by including well-scaled symptoms, staging characteristics and neuro-immune biomarkers, including immune-inflammatory assays, bioenergetic markers and brain imaging.

Source: Morris G, Maes M. Case definitions and diagnostic criteria for Myalgic Encephalomyelitis and Chronic fatigue Syndrome: from clinical-consensus to evidence-based case definitions. Neuro Endocrinol Lett. 2013;34(3):185-99. https://www.ncbi.nlm.nih.gov/pubmed/23685416

Comment:

Ellen M Goudsmit

2014 Mar 01 2:10 p.m.
Dr. Melvin Ramsay began writing about the illness now known as ME after the outbreak in north London in 1955. I looked in his book (1988) for a paper written by him in 1959 and found none. The best known article from 1959 was written by the late Dr. Acheson, who gave ME its name in a leader in the Lancet (1956). Dr Ramsay offered a diagnostic protocol but not until the 1980s.

I agree with Morris and Maes that the core symptom of ME is an exacerbation of symptoms following minimal exertion (supported by Paul et al who referred to CFS but actually selected patients with ME, pers. comm.). It should also be noted that none of the existing criteria for ME and CFS have been found to have the required specificity and sensitivity. And that includes the 2011 version.
The abstract indicates a lack of attention to detail. This undermines the understanding of the issues and shows a lack of respect, not only for the researchers but also for the patients, 99% of whom would know how to spell the name of arguably one of the most knowledgeable experts in this field. This failure to check for accuracy is a major cause for confusion in the literature on ME and CFS. And what happened to peer review? Any peer would have noticed the problem with the first sentence.
People really interested in ME and CFS may like to purchase an excellent publication by Shepherd and Chaudhuri summarising the knowledge to date. It’s available from the ME Association in the UK. An authoritative and accurate review (2013).
Leading article. A new clinical entity? Lancet, 1956, 1, 789-790.
Paul, L et al. Demonstration of delayed recovery from fatiguing exercise in chronic fatigue syndrome. European Journal of Neurology, 1999, 6, 63-69.
Ramsay, AM. Myalgic encephalomyelitis and postviral fatigue states. Second Ed. Gower Medical Publ. 1988. now available from the MEA Association, UK.

Diagnosis of myalgic encephalomyelitis: where are we now?

Abstract:

INTRODUCTION: The World Health Organization has classified myalgic encephalomyelitis (ME) as a neurological disease since 1969 considering chronic fatigue syndrome (CFS) as a synonym used interchangeably for ME since 1969. ME and CFS are considered to be neuro-immune disorders, characterized by specific symptom profiles and a neuro-immune pathophysiology. However, there is controversy as to which criteria should be used to classify patients with “chronic fatigue syndrome.”

AREAS COVERED: The Centers for Disease Control and Prevention (CDC) criteria consider chronic fatigue (CF) to be distinctive for CFS, whereas the International Consensus Criteria (ICC) stresses the presence of post-exertion malaise (PEM) as the hallmark feature of ME. These case definitions have not been subjected to rigorous external validation methods, for example, pattern recognition analyses, instead being based on clinical insights and consensus.

EXPERT OPINION: Pattern recognition methods showed the existence of three qualitatively different categories: (a) CF, where CF evident, but not satisfying full CDC syndrome criteria. (b) CFS, satisfying CDC criteria but without PEM. (c) ME, where PEM is evident in CFS. Future research on this “chronic fatigue spectrum” should, therefore, use the above-mentioned validated categories and novel tailored algorithms to classify patients into ME, CFS, or CF.

Comment in: Comment and reply on: ME is a distinct diagnostic entity, not part of a chronic fatigue spectrum. [Expert Opin Med Diagn. 2013]

Source: Maes M, Anderson G, Morris G, Berk M. Diagnosis of myalgic encephalomyelitis: where are we now? Expert Opin Med Diagn. 2013 May;7(3):221-5. doi: 10.1517/17530059.2013.776039. Epub 2013 Feb 27. https://www.ncbi.nlm.nih.gov/pubmed/23480562

Inflammatory and oxidative and nitrosative stress cascades as new drug targets in myalgic encephalomyelitis and chronic fatigue syndrome

Abstract:

Myalgic encephalomyelitis (ME), chronic fatigue syndrome (CFS) and chronic fatigue (CF) are distinct diagnostic categories with regard to clinical symptoms, severity of illness and biomarkers. Patients with ME and CFS show higher scores on fatigue, neurocognitive disorders, hyperalgesia, autonomic symptoms, postexertional malaise and a subjective feeling of infection than patients with CF. ME is characterized by increased postexertional malaise, a subjective feeling of infection and neurocognitive disorders and is a more severe variant than CFS.

Fukuda’s 1994 CDC criteria are adequate to make a distinction between patients with ME/CFS and CF, while ME/CFS patients should be subdivided into those with and without postexertional malaise into ME and CFS, respectively. Different interrelated pathophysiological mechanisms play a role in ME/CFS, i.e. (1) inflammation and immune activation, (2) oxidative and nitrosative stress and lowered antioxidant defenses, (3) activation of cell signaling networks, e.g. nuclear factor ĸβ, the 2 9 ,5 9 -oligoadenylate/RNase-L and/or protein kinase R pathway, (4) a transition towards autoimmune reactions, and (5) bacterial translocation.

The inflammatory biomarkers are higher in ME/CFS than in CF and higher in ME than in CFS. The above-mentioned pathways may explain the onset of characteristic ME/CFS symptoms, such as fatigue, malaise, autonomic symptoms, hyperalgesia, and neurocognitive symptoms. Different etiological factors may trigger ME/CFS/CF, e.g. viral and bacterial infections, and (auto)immune and inflammatory disorders, while psychosocial and physical stressors act as modulating factors. New pathophysiologically driven drug candidates for ME and CFS are discussed which target the pathways that play a role in ME/CFS.

Source: Maes M. Inflammatory and oxidative and nitrosative stress cascades as new drug targets in myalgic encephalomyelitis and chronic fatigue syndrome. Mod Trends Pharmacopsychiatri. 2013;28:162-74. doi: 10.1159/000343982. Epub 2013 Feb 27. https://www.ncbi.nlm.nih.gov/pubmed/25224898

Myalgic Encephalomyelitis (ME), Chronic Fatigue Syndrome (CFS), and Chronic Fatigue (CF) are distinguished accurately: results of supervised learning techniques applied on clinical and inflammatory data

Abstract:

There is much debate on the diagnostic classification of Myalgic Encephalomyelitis (ME), Chronic Fatigue Syndrome (CFS) and chronic fatigue (CF). Post-exertional malaise (PEM) is stressed as a key feature. This study examines whether CF and CFS, with and without PEM, are distinct diagnostic categories.

Fukuda’s criteria were used to diagnose 144 patients with chronic fatigue and identify patients with CFS and CF, i.e. those not fulfilling the Fukuda’s criteria. PEM was rated by means of a scale with defined scale steps between 0 and 6. CFS patients were divided into those with PEM lasting more than 24h (labeled: ME) and without PEM (labeled: CFS). The 12-item Fibromyalgia and Chronic Fatigue Syndrome (FF) Rating Scale was used to measure severity of illness. Plasma interleukin-1 (IL-1), tumor necrosis factor (TNF)α, and lysozyme, and serum neopterin were employed as external validating criteria.

Using fatigue, a subjective feeling of infection and PEM we found that ME, CFS, and CF were distinct categories. Patients with ME had significantly higher scores on concentration difficulties and a subjective experience of infection, and higher levels of IL-1, TNFα, and neopterin than patients with CFS. These biomarkers were significantly higher in ME and CFS than in CF patients. PEM loaded highly on the first two factors subtracted from the data set, i.e. “malaise-sickness” and “malaise-hyperalgesia”. Fukuda’s criteria are adequate to make a distinction between ME/CFS and CF, but ME/CFS patients should be subdivided into ME (with PEM) and CFS (without PEM).

Source: Maes M, Twisk FN, Johnson C. Myalgic Encephalomyelitis (ME), Chronic Fatigue Syndrome (CFS), and Chronic Fatigue (CF) are distinguished accurately: results of supervised learning techniques applied on clinical and inflammatory data. Psychiatry Res. 2012 Dec 30;200(2-3):754-60. doi: 10.1016/j.psychres.2012.03.031. Epub 2012 Apr 21. https://www.ncbi.nlm.nih.gov/pubmed/22521895

Do you think it’s a disease? a survey of medical students

Abstract:

BACKGROUND:

The management of medical conditions is influenced by whether clinicians regard them as “disease” or “not a disease”. The aim of the survey was to determine how medical students classify a range of conditions they might encounter in their professional lives and whether a different name for a condition would influence their decision in the categorisation of the condition as a ‘disease’ or ‘not a disease’.

METHODS: We surveyed 3 concurrent years of medical students to classify 36 candidate conditions into “disease” and “non-disease”. The conditions were given a ‘medical’ label and a (lay) label and positioned where possible in alternate columns of the survey.

RESULTS: The response rate was 96% (183 of 190 students attending a lecture): 80% of students concurred on 16 conditions as “disease” (eg diabetes, tuberculosis), and 4 as “non-disease” (eg baldness, menopause, fractured skull and heat stroke). The remaining 16 conditions (with 21-79% agreement) were more contentious (especially obesity, infertility, hay fever, alcoholism, and restless leg syndrome). Three pairs of conditions had both a more, and a less, medical label: the more medical labels (myalgic encephalomyelitis, hypertension, and erectile dysfunction) were more frequently classified as ‘disease’ than the less medical (chronic fatigue syndrome, high blood pressure, and impotence), respectively, significantly different for the first two pairs.

CONCLUSIONS: Some conditions excluded from the classification of “disease” were unexpected (eg fractured skull and heat stroke). Students were mostly concordant on what conditions should be classified as “disease”. They were more likely to classify synonyms as ‘disease’ if the label was medical. The findings indicate there is still a problem 30 years on in the concept of ‘what is a disease’. Our findings suggest that we should be addressing such concepts to medical students.

Source: Erueti C, Glasziou P, Mar CD, van Driel ML. Do you think it’s a disease? a survey of medical students. BMC Med Educ. 2012 Apr 3;12:19. doi: 10.1186/1472-6920-12-19. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3383512/ (Full article)

Contrasting case definitions for chronic fatigue syndrome, Myalgic Encephalomyelitis/chronic fatigue syndrome and myalgic encephalomyelitis

Abstract:

This article uses data from patients recruited using the 1994 case definition of chronic fatigue syndrome (CFS) to contrast those meeting criteria for the Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS) Canadian case definition with those that did not meet these criteria. The study also contrasts those meeting criteria for Myalgic Encephalomyelitis (ME) based on criteria from Ramsay and other theorists with those that did not meet the ME criteria. The ME/CFS case definition criteria identified a subset of patients with more functional impairments and physical, mental, and cognitive problems than the subset not meeting these criteria. The ME subset had more functional impairments, and more severe physical and cognitive symptoms than the subset not meeting ME criteria. When applied to a population meeting the 1994 CFS case definition, both ME/CFS and ME criteria appear to select a more severe subset of patients.

Source: Jason LA, Brown A, Clyne E, Bartgis L, Evans M, Brown M. Contrasting case definitions for chronic fatigue syndrome, Myalgic Encephalomyelitis/chronic fatigue syndrome and myalgic encephalomyelitis. Eval Health Prof. 2012 Sep;35(3):280-304. doi: 10.1177/0163278711424281. Epub 2011 Dec 7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3658447/ (Full article)

Myalgic encephalomyelitis: International Consensus Criteria

Abstract:

The label ‘chronic fatigue syndrome’ (CFS) has persisted for many years because of the lack of knowledge of the aetiological agents and the disease process. In view of more recent research and clinical experience that strongly point to widespread inflammation and multisystemic neuropathology, it is more appropriate and correct to use the term ‘myalgic encephalomyelitis’ (ME) because it indicates an underlying pathophysiology. It is also consistent with the neurological classification of ME in the World Health Organization’s International Classification of Diseases (ICD G93.3).

Consequently, an International Consensus Panel consisting of clinicians, researchers, teaching faculty and an independent patient advocate was formed with the purpose of developing criteria based on current knowledge. Thirteen countries and a wide range of specialties were represented. Collectively, members have approximately 400 years of both clinical and teaching experience, authored hundreds of peer-reviewed publications, diagnosed or treated approximately 50 000 patients with ME, and several members coauthored previous criteria. The expertise and experience of the panel members as well as PubMed and other medical sources were utilized in a progression of suggestions/drafts/reviews/revisions.

The authors, free of any sponsoring organization, achieved 100% consensus through a Delphi-type process. The scope of this paper is limited to criteria of ME and their application. Accordingly, the criteria reflect the complex symptomatology. Operational notes enhance clarity and specificity by providing guidance in the expression and interpretation of symptoms. Clinical and research application guidelines promote optimal recognition of ME by primary physicians and other healthcare providers, improve the consistency of diagnoses in adult and paediatric patients internationally and facilitate clearer identification of patients for research studies.

Comment in: A controversial consensus–comment on article by Broderick et al. [J Intern Med. 2012]

Source: Carruthers BM, van de Sande MI, De Meirleir KL, Klimas NG, Broderick G, Mitchell T, Staines D, Powles AC, Speight N, Vallings R, Bateman L, Baumgarten-Austrheim B, Bell DS, Carlo-Stella N, Chia J, Darragh A, Jo D, Lewis D, Light AR, Marshall-Gradisbik S, Mena I, Mikovits JA, Miwa K, Murovska M, Pall ML, Stevens S. Myalgic encephalomyelitis: International Consensus Criteria. J Intern Med. 2011 Oct;270(4):327-38. doi: 10.1111/j.1365-2796.2011.02428.x. Epub 2011 Aug 22. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3427890/ (Full article)

The prognosis of different fatigue diagnostic labels: a longitudinal survey

Abstract:

BACKGROUND: Several different diagnostic labels exist for the fatigue syndromes, including chronic fatigue syndrome (CFS), myalgic encephalomyelitis (ME) and postviral fatigue syndrome (PVFS). An allied condition is fibromyalgia. No study has examined prognostic differences across these different labels.

OBJECTIVE: To compare the prognoses of patients labelled with different fatigue syndromes in primary care.

METHODS: We performed a longitudinal survey, using electronic records from the General Practice Research Database. All 18,122 patients diagnosed by their GP with a fatigue syndrome from 1988-2001 with a minimum of one year of records after diagnosis were collated into four groups: CFS, ME, PVFS and fibromyalgia. CFS and ME were combined for the main analysis as no code for CFS was available until 1995. The length of illness was calculated as the interval between the diagnosis and the last recorded fatigue symptom, expressed as days per year, to account for differing lengths of record after diagnosis.

RESULTS: Patients with CFS/ME combined had a worse prognosis (median length of illness 80 days per year; interquartile range 0-242) than fibromyalgia (51; 0-244) or PVFS 0 (0-108), a significant difference, P < 0.001. In a subgroup analysis, ME had a worse prognosis (median length of illness in days per year 106; interquartile range 0-259) than CFS (33; 0-170), P < 0.001, in spite of a better course before diagnosis. Secondary outcome measures were consistent with these results.

CONCLUSION: There were important differences in outcome between the various fatigue labels, with ME having the worst prognosis and PVFS the best. This could be an adverse effect of the label ME itself. Alternatively, patients who are destined to have a worse prognosis may preferentially attract the ME label. Our data support the first interpretation.

Source: Hamilton WT, Gallagher AM, Thomas JM, White PD. The prognosis of different fatigue diagnostic labels: a longitudinal survey. Fam Pract. 2005 Aug;22(4):383-8. Epub 2005 Apr 1. http://fampra.oxfordjournals.org/content/22/4/383.long (Full article)