Tag: review

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

Assessment of the scientific rigour of randomized controlled trials on the effectiveness of cognitive behavioural therapy and graded exercise therapy for patients with myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review

Abstract:

Cognitive behavioural therapy and graded exercise therapy have been promoted as effective treatments for patients with myalgic encephalomyelitis/chronic fatigue syndrome. However, criticism on the scientific rigour of these studies has been raised. This review assessed the methodological quality of studies on the effectiveness of cognitive behavioural therapy and graded exercise therapy. The methodological quality of the 18 included studies was found to be relatively low, as bias was prominently found, affecting the main outcome measures of the studies (fatigue, physical functioning and functional impairment/status). Future research should focus on including more objective outcome measures in a well-defined patient population.

Source: Ahmed SA, Mewes JC, Vrijhoef H. Assessment of the scientific rigour of randomized controlled trials on the effectiveness of cognitive behavioural therapy and graded exercise therapy for patients with myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review. J Health Psychol. 2019 May 10:1359105319847261. doi: 10.1177/1359105319847261. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31072121

The ‘cognitive behavioural model’ of chronic fatigue syndrome: Critique of a flawed model

Abstract:

Chronic fatigue syndrome/myalgic encephalomyelitis is a debilitating illness that greatly impacts the lives of sufferers. A cognitive behavioural model attempts to explain illness onset and continuance with a hypothesis that the illness is perpetuated by patients’ irrational beliefs and avoidance behaviours. This theory underpins the promotion of cognitive behavioural therapy, a treatment that aims to change beliefs and behaviours. This article reports on a detailed review of the cognitive behavioural model. Our review finds that the model lacks high-quality evidential support, conflicts with accounts given by most patients and fails to account for accumulating biological evidence of pathological and physiological abnormalities found in patients. There is little scientific credibility in the claim that psycho-behavioural therapies are a primary treatment for this illness.

Source: Keith Geraghty, Leonard Jason, Madison Sunnquist, David Tuller, Charlotte Blease, Charles Adeniji. The ‘cognitive behavioural model’ of chronic fatigue syndrome: Critique of a flawed model. Health Psychology Open, Volume: 6 issue: 1,
Article first published online: April 23, 2019; Issue published: January 1, 2019. https://journals.sagepub.com/doi/10.1177/2055102919838907 (Full article)

Chronotropic Intolerance: An Overlooked Determinant of Symptoms and Activity Limitation in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome?

Abstract:

Post-exertional malaise (PEM) is the hallmark clinical feature of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). PEM involves a constellation of substantially disabling signs and symptoms that occur in response to physical, mental, emotional, and spiritual over-exertion. Because PEM occurs in response to over-exertion, physiological measurements obtained during standardized exertional paradigms hold promise to contribute greatly to our understanding of the cardiovascular, pulmonary, and metabolic states underlying PEM.

In turn, information from standardized exertional paradigms can inform patho-etiologic studies and analeptic management strategies in people with ME/CFS. Several studies have been published that describe physiologic responses to exercise in people with ME/CFS, using maximal cardiopulmonary testing (CPET) as a standardized physiologic stressor. In both non-disabled people and people with a wide range of health conditions, the relationship between exercise heart rate (HR) and exercise workload during maximal CPET are repeatable and demonstrate a positive linear relationship.

However, smaller or reduced increases in heart rate during CPET are consistently observed in ME/CFS. This blunted rise in heart rate is called chronotropic intolerance (CI). CI reflects an inability to appropriately increase cardiac output because of smaller than expected increases in heart rate. The purposes of this review are to (1) define CI and discuss its applications to clinical populations; (2) summarize existing data regarding heart rate responses to exercise obtained during maximal CPET in people with ME/CFS that have been published in the peer-reviewed literature through systematic review and meta-analysis; and (3) discuss how trends related to CI in ME/CFS observed in the literature should influence future patho-etiological research designs and clinical practice.

Source: Todd E. Davenport, Mary Lehnen, Staci R. Stevens, J. Mark VanNess, Jared Stevens and Christopher R. Snell. Chronotropic Intolerance: An Overlooked Determinant of Symptoms and Activity Limitation in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome? Front. Pediatr., 22 March 2019 | https://doi.org/10.3389/fped.2019.00082 https://www.frontiersin.org/articles/10.3389/fped.2019.00082/full (Full article)

The Invisible Burden of Chronic Fatigue in the Community: a Narrative Review

Abstract:

PURPOSE OF REVIEW: Unexplained fatigue is commonly reported in the general population, with varying severity. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) sits at the extreme of the fatigue continuum, yet more individuals experience unexplained prolonged fatigue (1-6-month duration) or chronic fatigue (> 6 months) that, although debilitating, does not fulfil ME/CFS criteria. This review examines the empirical literature comparing symptoms for those with prolonged fatigue, chronic fatigue and ME/CFS.

RECENT FINDINGS: Substantial overlap of self-reported psychological, physical and functional impairments exists between chronic fatigue and ME/CFS. The conversion rate from prolonged or chronic fatigue to ME/CFS is not understood. Current research has failed to uncover factors accounting for differences in fatigue trajectories, nor incorporate comprehensive, longitudinal assessments extending beyond self-reported symptoms. Distinguishing factors between prolonged fatigue, chronic fatigue and ME/CFS remain poorly understood, highlighting a need for longitudinal studies integrating biopsychosocial approaches to inform early management and targeted rehabilitation strategies.

Source: Fatt SJ, Cvejic E2,, Lloyd AR, Vollmer-Conna U, Beilharz JE. The Invisible Burden of Chronic Fatigue in the Community: a Narrative Review. Curr Rheumatol Rep. 2019 Feb 11;21(2):5. doi: 10.1007/s11926-019-0804-2.

Myalgic encephalomyelitis or chronic fatigue syndrome: how could the illness develop?

Abstract:

A model of the development and progression of chronic fatigue syndrome (myalgic encephalomyelitis), the aetiology of which is currently unknown, is put forward, starting with a consideration of the post-infection role of damage-associated molecular patterns and the development of chronic inflammatory, oxidative and nitrosative stress in genetically predisposed individuals.

The consequences are detailed, including the role of increased intestinal permeability and the translocation of commensal antigens into the circulation, and the development of dysautonomia, neuroinflammation, and neurocognitive and neuroimaging abnormalities. Increasing levels of such stress and the switch to immune and metabolic downregulation are detailed next in relation to the advent of hypernitrosylation, impaired mitochondrial performance, immune suppression, cellular hibernation, endotoxin tolerance and sirtuin 1 activation.

The role of chronic stress and the development of endotoxin tolerance via indoleamine 2,3-dioxygenase upregulation and the characteristics of neutrophils, monocytes, macrophages and T cells, including regulatory T cells, in endotoxin tolerance are detailed next. Finally, it is shown how the immune and metabolic abnormalities of chronic fatigue syndrome can be explained by endotoxin tolerance, thus completing the model.

Source: Gerwyn Morris, Michael Maes, Michael Berk, Basant K. Puri. Myalgic encephalomyelitis or chronic fatigue syndrome: how could the illness develop? Metabolic Brain Disease. Review Article, First Online: 13 February 2019 https://doi.org/10.1007/s11011-019-0388-6 (Full article)

Neuroinflammation and Cytokines in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Critical Review of Research Methods

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is the label given to a syndrome that can include long-term flu-like symptoms, profound fatigue, trouble concentrating, and autonomic problems, all of which worsen after exertion. It is unclear how many individuals with this diagnosis are suffering from the same condition or have the same underlying pathophysiology, and the discovery of biomarkers would be clarifying.

The name “myalgic encephalomyelitis” essentially means “muscle pain related to central nervous system inflammation” and many efforts to find diagnostic biomarkers have focused on one or more aspects of neuroinflammation, from periphery to brain. As the field uncovers the relationship between the symptoms of this condition and neuroinflammation, attention must be paid to the biological mechanisms of neuroinflammation and issues with its potential measurement.

The current review focuses on three methods used to study putative neuroinflammation in ME/CFS: (1) positron emission tomography (PET) neuroimaging using translocator protein (TSPO) binding radioligand (2) magnetic resonance spectroscopy (MRS) neuroimaging and (3) assays of cytokines circulating in blood and cerebrospinal fluid. PET scanning using TSPO-binding radioligand is a promising option for studies of neuroinflammation. However, methodological difficulties that exist both in this particular technique and across the ME/CFS neuroimaging literature must be addressed for any results to be interpretable.

We argue that the vast majority of ME/CFS neuroimaging has failed to use optimal techniques for studying brainstem, despite its probable centrality to any neuroinflammatory causes or autonomic effects. MRS is discussed as a less informative but more widely available, less invasive, and less expensive option for imaging neuroinflammation, and existing studies using MRS neuroimaging are reviewed. Studies seeking to find a peripheral circulating cytokine “profile” for ME/CFS are reviewed, with attention paid to the biological and methodological reasons for lack of replication among these studies.

We argue that both the biological mechanisms of cytokines and the innumerable sources of potential variance in their measurement make it unlikely that a consistent and replicable diagnostic cytokine profile will ever be discovered.

Source: Michael B. VanElzakker, Sydney A. Brumfield and Paula S. Lara Mejia. Neuroinflammation and Cytokines in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Critical Review of Research Methods. Front. Neurol., 10 January 2019 | https://doi.org/10.3389/fneur.2018.01033 https://www.frontiersin.org/articles/10.3389/fneur.2018.01033/full?fbclid=IwAR3KxhofUaLakZRPNiyBliNHSlJvUOdsVqVf5cED_i6o5gF9MCbWxpeS298#h7 (Full article)

Chronic fatigue syndrome (CFS): Suggestions for a nutritional treatment in the therapeutic approach

Abstract:

Chronic fatigue syndrome (CFS) is known as a multi-systemic and complex illness, which induces fatigue and long-term disability in educational, occupational, social, or personal activities. The diagnosis of this disease is difficult, due to lacking a proper and suited diagnostic laboratory test, besides to its multifaceted symptoms. Numerous factors, including environmental and immunological issues, and a large spectrum of CFS symptoms, have recently been reported.

In this review, we focus on the nutritional intervention in CFS, discussing the many immunological, environmental, and nutritional aspects currently investigated about this disease. Changes in immunoglobulin levels, cytokine profiles and B- and T- cell phenotype and declined cytotoxicity of natural killer cells, are commonly reported features of immune dysregulation in CFS. Also, some nutrient deficiencies (vitamin C, vitamin B complex, sodium, magnesium, zinc, folic acid, l-carnitine, l-tryptophan, essential fatty acids, and coenzyme Q10) appear to be important in the severity and exacerbation of CFS symptoms. This review highlights a far-driven analysis of mineral and vitamin deficiencies among CFS patients.

Source: Bjørklund G, Dadar M, Pen JJ, Chirumbolo S, Aaseth J. Chronic fatigue syndrome (CFS): Suggestions for a nutritional treatment in the therapeutic approach. Biomed Pharmacother. 2019 Jan;109:1000-1007. doi: 10.1016/j.biopha.2018.10.076. Epub 2018 Nov 5.  https://www.sciencedirect.com/science/article/pii/S0753332218342987?via%3Dihub (Full article)

Chronic viral infections in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Abstract:

BACKGROUND AND MAIN TEXT: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex and controversial clinical condition without having established causative factors. Increasing numbers of cases during past decade have created awareness among patients as well as healthcare professionals. Chronic viral infection as a cause of ME/CFS has long been debated. However, lack of large studies involving well-designed patient groups and validated experimental set ups have hindered our knowledge about this disease. Moreover, recent developments regarding molecular mechanism of pathogenesis of various infectious agents cast doubts over validity of several of the past studies.

CONCLUSIONS: This review aims to compile all the studies done so far to investigate various viral agents that could be associated with ME/CFS. Furthermore, we suggest strategies to better design future studies on the role of viral infections in ME/CFS.

Source: Rasa S, Nora-Krukle Z, Henning N, Eliassen E, Shikova E, Harrer T, Scheibenbogen C, Murovska M, Prusty BK6; European Network on ME/CFS (EUROMENE). Chronic viral infections in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). J Transl Med. 2018 Oct 1;16(1):268. doi: 10.1186/s12967-018-1644-y. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6167797/ (Full article)