Tag: PEM

Discriminative validity of metabolic and workload measurements for identifying people with chronic fatigue syndrome

Abstract:

BACKGROUND: Reduced functional capacity and postexertion fatigue after physical activity are hallmark symptoms of chronic fatigue syndrome (CFS) and may even qualify for biomarker status. That these symptoms are often delayed may explain the equivocal results for clinical cardiopulmonary exercise testing in people with CFS. Test reproducibility in people who are healthy is well documented. Test reproducibility may not be achievable in people with CFS because of delayed symptoms.

OBJECTIVE: The objective of this study was to determine the discriminative validity of objective measurements obtained during cardiopulmonary exercise testing to distinguish participants with CFS from participants who did not have a disability but were sedentary.

DESIGN: A prospective cohort study was conducted.

METHODS: Gas exchange data, workloads, and related physiological parameters were compared in 51 participants with CFS and 10 control participants, all women, for 2 maximal exercise tests separated by 24 hours.

RESULTS: Multivariate analysis showed no significant differences between control participants and participants with CFS for test 1. However, for test 2, participants with CFS achieved significantly lower values for oxygen consumption and workload at peak exercise and at the ventilatory or anaerobic threshold. Follow-up classification analysis differentiated between groups with an overall accuracy of 95.1%.

LIMITATIONS: Only individuals with CFS who were able to undergo exercise testing were included in this study. Individuals who were unable to meet the criteria for maximal effort during both tests, were unable to complete the 2-day protocol, or displayed overt cardiovascular abnormalities were excluded from the analysis.

CONCLUSIONS: The lack of any significant differences between groups for the first exercise test would appear to support a deconditioning hypothesis for CFS symptoms. However, the results from the second test indicated the presence of CFS-related postexertion fatigue. It might be concluded that a single exercise test is insufficient to reliably demonstrate functional impairment in people with CFS. A second test might be necessary to document the atypical recovery response and protracted fatigue possibly unique to CFS, which can severely limit productivity in the home and workplace.

 

Source: Snell CR, Stevens SR, Davenport TE, Van Ness JM.Discriminative validity of metabolic and workload measurements for identifying people with chronic fatigue syndrome. Phys Ther. 2013 Nov;93(11):1484-92. doi: 10.2522/ptj.20110368. Epub 2013 Jun 27. https://academic.oup.com/ptj/article/93/11/1484/2735315/Discriminative-Validity-of-Metabolic-and-Workload?searchresult=1 (Full article)

 

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).

Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

 

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

 

Postexertional malaise in women with chronic fatigue syndrome

Abstract:

OBJECTIVE: Postexertional malaise (PEM) is a defining characteristic of chronic fatigue syndrome (CFS) that remains a source of some controversy. The purpose of this study was to explore the effects of an exercise challenge on CFS symptoms from a patient perspective.

METHODS: This study included 25 female CFS patients and 23 age-matched sedentary controls. All participants underwent a maximal cardiopulmonary exercise test. Subjects completed a health and well-being survey (SF-36) 7 days postexercise. Subjects also provided, approximately 7 days after testing, written answers to open-ended questions pertaining to physical and cognitive responses to the test and length of recovery. SF-36 data were compared using multivariate analyses. Written questionnaire responses were used to determine recovery time as well as number and type of symptoms experienced.

RESULTS: Written questionnaires revealed that within 24 hours of the test, 85% of controls indicated full recovery, in contrast to 0 CFS patients. The remaining 15% of controls recovered within 48 hours of the test. In contrast, only 1 CFS patient recovered within 48 hours. Symptoms reported after the exercise test included fatigue, light-headedness, muscular/joint pain, cognitive dysfunction, headache, nausea, physical weakness, trembling/instability, insomnia, and sore throat/glands. A significant multivariate effect for the SF-36 responses (p < 0.001) indicated lower functioning among the CFS patients, which was most pronounced for items measuring physiological function.

CONCLUSIONS: The results of this study suggest that PEM is both a real and an incapacitating condition for women with CFS and that their responses to exercise are distinctively different from those of sedentary controls.

Source: VanNess JM, Stevens SR, Bateman L, Stiles TL, Snell CR. Postexertional malaise in women with chronic fatigue syndrome. J Womens Health (Larchmt). 2010 Feb;19(2):239-44. doi: 10.1089/jwh.2009.1507. https://www.ncbi.nlm.nih.gov/pubmed/20095909

 

Use of exercise for treatment of chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a condition that results in moderate to severe disability, the primary feature of which is fatigue of unknown origin. There is a lot of interest in classifying, characterising and treating patients with CFS. Currently, the two major theories of a medical cause of CFS are viral infection and immune dysregulation.

Patients report critical reductions in levels of physical activity, and many experience ‘relapses’ of severe symptoms following even moderate levels of exertion. Despite this, most studies report CFS patients to have normal muscle strength and either normal or slightly reduced muscle endurance.

Histological and metabolic studies report mixed results: CFS patients have either no impairment or mild impairment of mitochondria and oxidative metabolism compared with sedentary controls.

Current treatments for CFS are symptom-based, with psychological, pharmacological and rehabilitation treatments providing some relief but no cure. Immunological and nutritional treatments have been tried but have not provided reproducible benefits. Exercise training programmes are thought to be beneficial (if ‘relapses’ can be avoided), although few controlled studies have been performed.

CFS is a long-lasting disorder that can slowly improve with time, but often does not. Further studies are needed to better understand the multiple factors that can cause chronic fatigue illness, as well as the effect that exercise training has on the symptoms of CFS.

 

Source: McCully KK, Sisto SA, Natelson BH. Use of exercise for treatment of chronic fatigue syndrome. Sports Med. 1996 Jan;21(1):35-48. http://www.ncbi.nlm.nih.gov/pubmed/8771284

 

Chronic fatigue syndrome–a review of the literature

Abstract:

Chronic fatigue syndrome is a clinical condition characterized by abnormal fatigue, subfebrile body temperature, sore throat, lymphadenopathy, arthralgia, myalgia and neuropsychiatric symptoms. Typically, the syndrome develops after a flu-like illness and is markedly exacerbated by exercise. The etiology is unknown and there is no single diagnostic test. The patients may have cognitive dysfunction, immunological and endocrinological abnormalities and abnormal mitochondria. Magnetic resonance imaging scans may show increased uptake of signals in the brain, and single photon emission computerized tomography reveals regional hypoperfusion of the brain. The author discusses similarities and distinctions between the syndrome and depression.

 

Source: Hamre HJ. Chronic fatigue syndrome–a review of the literature. Tidsskr Nor Laegeforen. 1995 Oct 10;115(24):3042-5. [Article in Norwegian] http://www.ncbi.nlm.nih.gov/pubmed/7570537