How relevant are exercise capacity measures for evaluating treatment effects in chronic fatigue syndrome? Results from a prospective, multidisciplinary outcome study

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

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.

Multidisciplinary rehabilitation treatment versus cognitive behavioural therapy for patients with chronic fatigue syndrome: a randomized controlled trial

OBJECTIVES

The aim of this trial was to evaluate the difference in treatment effect, at 26 and 52 weeks after the start of treatment, between cognitive behavioural therapy (CBT) and multidisciplinary rehabilitation treatment (MRT) for patients with chronic fatigue syndrome (CFS).

DESIGN

Multicentre, randomized controlled trial of patients with CFS. Participants were randomly assigned to MRT or CBT.

SETTING

Four rehabilitation centres in the Netherlands.

SUBJECTS

A total of 122 patients participated in the trial.

MAIN OUTCOME MEASURES

Primary outcomes were fatigue measured by the fatigue subscale of the Checklist Individual Strength and health-related quality of life measured by the Short-Form 36. Outcomes were assessed prior to treatment and at 26 and 52 weeks after treatment initiation.

RESULTS

A total of 114 participants completed the assessment at 26 weeks, and 112 completed the assessment at 52 weeks. MRT was significantly more effective than CBT in reducing fatigue at 52 weeks. The estimated difference in fatigue between the two treatments was -3.02 [95% confidence interval (CI) -8.07 to 2.03; P = 0.24] at 26 weeks and -5.69 (95% CI -10.62 to -0.76; P = 0.02) at 52 weeks. Patients showed an improvement in quality of life over time, but between-group differences were not significant.

CONCLUSION

This study provides evidence that MRT is more effective in reducing long-term fatigue severity than CBT in patients with CFS. Although implementation in comparable populations can be recommended based on clinical effectiveness, it is advisable to analyse the cost-effectiveness and replicate these findings in another multicentre trial.

The role of the hippocampus in the pathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a severe acquired illness characterized by a profound sensation of fatigue, not ameliorated by rest and resulting in a substantial decrease in the amount and quality of occupational, social and recreational activities. Despite intense research, the aetiology and pathogenesis of ME/CFS is still unknown and no conclusive biological markers have been found. As a consequence, an accepted curative treatment is still lacking and rehabilitation programmes are not very effective, as few patients recover. Increased knowledge of the mechanisms leading to the emergence and maintenance of the illness is called for. In this study, I will put forth an alternative hypothesis to explain some of the pathologies associated with ME/CFS, by concentrating on one of the major strategic organs of the brain, the hippocampus. I will show that the ME/CFS triggering factors also impact the hippocampus, leading to neurocognitive deficits and disturbances in the regulation of the stress system and pain perception. These deficits lead to a substantial decrease in activity and to sleep disorders, which, in turn, impact the hippocampus and initiate a vicious circle of increased disability.

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

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.

How to exercise people with chronic fatigue syndrome: evidence-based practice guidelines

BACKGROUND

Despite the large number of studies emphasizing the effectiveness of graded exercise therapy (GET) and cognitive behavioural therapy (CBT) for people with chronic fatigue syndrome (CFS), clinicians are left wondering how exactly to apply exercise therapy to their patients with CFS. The aim of this literature review is to identify the appropriate exercise modalities (i.e. exercise duration, mode, number of treatment sessions, session length, duration of treatment, exercise intensity and whether or not to apply home exercise program) for people with CFS.

MATERIALS AND METHODS

All studies that were identified through electronic databases (PubMed and PEDro) were assessed for methodological quality by using selection criteria (Delphi score).

RESULTS

In this literature review, 12 studies fulfilled all study requirements. One study had a low methodological quality. The parameters used in the GET and CBT interventions were divided into subgroups: (i) time or symptom contingent, (ii) exercise frequency and (iii) exercise modality.

CONCLUSION

The lack of uniformity in outcome measures and CFS diagnostic criteria make it difficult to compare the findings across studies. Based on the available evidence, exercise therapy for people with CFS should be aerobic and must comprise of 10-11 sessions spread over a period of 4-5 months. A time-contingent approach is preferred over a symptom-contingent way of exercising. In addition, people with CFS can perform home exercises five times a week with an initial duration of 5-15 min per exercise session. The exercise duration can be gradually increased up to 30 min.

Deviations in daily physical activity patterns in patients with the chronic fatigue syndrome: a case control study

OBJECTIVES

Deviations in daily physical activity patterns may play an important role in the development and maintenance of fatigue in the chronic fatigue syndrome (CFS). The aim of this study is to gain insight into the objective daily physical activity pattern of patients with CFS in comparison with healthy controls. The secondary objective is studying the awareness in performing physical activities.

METHODS

The objective daily physical activity pattern was measured with a tri-axial accelerometer in 35 patients with CFS and in 35 age- and gender-matched healthy controls. The objective daily physical activity level and distribution of physical activities at low, medium and high intensity levels during the day were measured. Moreover, variability in performing physical activities within and between subjects was computed. Subjective ratings of self-reported daily physical activity levels were assessed at a visual analog scale.

RESULTS

CFS patients were significantly less physically active in the afternoon and evening, and spent fewer activities at high intensity levels and more at low intensity levels. Moreover, CFS patients showed more variability in their own physical activity pattern during the afternoon. The heterogeneity in the physical activity pattern between subjects within the CFS and control group did not differ. Finally, CFS patients were more aware about their daily physical activity level than healthy controls.

CONCLUSION

CFS patients showed deviations in the objectively measured daily physical activity pattern. Future research should elucidate the relation between impaired balances in daily physical activity patterns and fatigue severity in CFS.

Chronic fatigue syndrome, fibromyalgia, and related illnesses: a clinical model of assessment and intervention

A clinically informative behavioral literature on chronic fatigue syndrome (CFS) and fibromyalgia (FM) has emerged over the past decade. The purpose of this article is to (a) define these conditions and their less severe counterparts, i.e., unexplained chronic fatigue (UCF) and chronic widespread pain; (b) briefly review the behavioral theory and intervention literature on CFS and FM; and (c) describe a user-friendly clinical model of assessment and intervention for these illnesses. The assessments described will facilitate understanding of the somewhat unusual and puzzling somatic presentations that characterize these patients. Using an individualized cognitive-behavioral approach the mental health clinician can offer significant help to these often stigmatized and medically underserved patients.

Graduated exercise training and progressive resistance training in adolescents with chronic fatigue syndrome: a randomized controlled pilot study

Objective: To investigate the differential effects of aerobic graded exercise and progressive resistance training on exercise tolerance, fatigue and quality of life in adolescent patients with chronic fatigue syndrome (CFS).

Design: Single-blind, randomized controlled pilot trial.

Setting: A major metropolitan hospital in Melbourne, Australia.

Subjects: Twenty-two adolescents aged 13—18 years diagnosed with CFS and admitted to the inpatient chronic fatigue rehabilitation programme.

Intervention: Patients were randomized to either graded aerobic exercise training or a progressive resistance training programme, for five days/week for four weeks. The graded aerobic training consisted of 20—40 minutes of stationary cycling and treadmill exercise. The progressive resistance training involved 16 exercises performed with single set, moderate load and high repetitions.

Main measures: Exercise tolerance (time to fatigue) measured on a graded sub-maximal treadmill test, metabolic equivalents and quality of life, along with muscular strength (maximium push-ups) and endurance (sit-to-stand) and questionnaires evaluating depressive symptoms and fatigue severity.

Results: No intervention was significantly better than the other for any outcome. However, physical capacity and quality of life significantly improved in both groups, while fatigue severity and symptoms of depression improved only with aerobic training.

Conclusions: Resistance and aerobic training resulted in similar changes to physical capacity, quality of life and fatigue severity. Generally, patients who completed resistance training or aerobic training experienced significant improvements in outcomes from baseline when they entered the programme. Whether these improvements can be attributed to the treatment is unknown.

Conceptual model for physical therapist management of chronic fatigue syndrome/myalgic encephalomyelitis

Fatigue is one of the most common reasons why people consult health care providers. Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is one cause of clinically debilitating fatigue. The underdiagnosis of CFS/ME, along with the spectrum of symptoms that represent multiple reasons for entry into physical therapy settings, places physical therapists in a unique position to identify this health condition and direct its appropriate management. The diagnosis and clinical correlates of CFS/ME are becoming better understood, although the optimal clinical management of this condition remains controversial. The 4 aims of this perspective article are: (1) to summarize the diagnosis of CFS/ME with the goal of promoting the optimal recognition of this condition by physical therapists; (2) to discuss aerobic system and cognitive deficits that may lead to the clinical presentation of CFS/ME; (3) to review the evidence for graded exercise with the goal of addressing limitations in body structures and functions, activity, and participation in people with CFS/ME; and (4) to present a conceptual model for the clinical management of CFS/ME by physical therapists.

Customizing treatment of chronic fatigue syndrome and fibromyalgia: the role of perpetuating factors

BACKGROUND

Syndromes characterized by chronic, medically unexplained fatigue, effort- and stress-intolerance, and widespread pain are highly prevalent in medicine.

RESULTS

In chronic fatigue syndrome (CFS) and fibromyalgia (FM), various perpetuating factors may impair patients' quality of life and functioning and impede recovery. Although cognitive-behavioral and graded-exercise therapy are evidence-based treatments, the effectiveness and acceptability of therapeutic interventions in CFS/FM may largely depend on a customized approach taking the heterogeneity of perpetuating factors into account.

CONCLUSION

Further research should clarify the aim and outcome of different treatment strategies in CFS/FM, as well as the underlying mechanisms of change, including those facilitating neurobiological recovery.

Effectiveness of distant healing for patients with chronic fatigue syndrome: a randomised controlled partially blinded trial (EUHEALS)

BACKGROUND

Distant healing, a form of spiritual healing, is widely used for many conditions but little is known about its effectiveness.

METHODS

In order to evaluate distant healing in patients with a stable chronic condition, we randomised 409 patients with chronic fatigue syndrome (CFS) from 14 private practices for environmental medicine in Germany and Austria in a two by two factorial design to immediate versus deferred (waiting for 6 months) distant healing. Half the patients were blinded and half knew their treatment allocation. Patients were treated for 6 months and allocated to groups of 3 healers from a pool of 462 healers in 21 European countries with different healing traditions. Change in Mental Health Component Summary (MHCS) score (SF-36) was the primary outcome and Physical Health Component Summary score (PHCS) the secondary outcome.

RESULTS

This trial population had very low quality of life and symptom scores at entry. There were no differences over 6 months in post-treatment MHCS scores between the treated and untreated groups. There was a non-significant outcome (p = 0.11) for healing with PHCS (1.11; 95% CI -0.255 to 2.473 at 6 months) and a significant effect (p = 0.027) for blinding; patients who were unblinded became worse during the trial (-1.544; 95% CI -2.913 to -0.176). We found no relevant interaction for blinding among treated patients in MHCS and PHCS. Expectation of treatment and duration of CFS added significantly to the model.

CONCLUSIONS

In patients with CFS, distant healing appears to have no statistically significant effect on mental and physical health but the expectation of improvement did improve outcome.

Relationship between aerobic fitness and quality of life in female fibromyalgia patients

Objective: To determine whether there is a direct link between quality of life and aerobic capacity among female fibromyalgia patients.

Design: Cross-section study.

Setting: University of León.

Subjects: Twenty-nine women belonging to the León Fibromyalgia and Chronic Fatigue Association.

Main measurements: Aerobic capacity and quality of life were measured by means of the Six-Minute Walk Test and the Fibromyalgia Impact Questionnaire. Outcome measures included heart rate and rate of perceived fatigue and dypsnoea.

Results: The average distance walked was 432.8 (61.2) m and the total average Fibromyalgia Impact Questionnaire score was 47.5 (18.9). Only item 1 of the Fibromyalgia Impact Questionnaire, physical function, showed any statistically significant link with the distance walked, which had no statistically significant relationship with any of the variables studied.

Conclusion: The physical fitness of women with fibromyalgia, as determined by the Six-Minute Walk Test and the Fibromyalgia Impact Questionnaire, has no direct relation with quality of life as the patients perceive it.

Rehabilitation of decreased motor performance in patients with chronic fatigue syndrome: should we treat low effort capacity or reduced effort tolerance?

Aim: The aetiology, pathophysiology, diagnostic delineation and treatment of chronic fatigue syndrome (CFS) remain a matter of debate. Here some aspects of the debate are elucidated, with a particular focus on the patients' decreased motor performance.

Hypothesis: The pathophysiological basis of decreased motor performance in CFS may, theoretically, involve three components: (1) a peripheral energetic deficit (impaired oxidative metabolism and/or physical deconditioning); (2) a central perceptual disturbance (higher effort sense or increased `interoception'); and (3) a fundamental failure of the neurobiological stress system, leading to an abnormal `sickness response'. It is proposed that the first two components may lead to low effort capacity, while the third component may lead to reduced effort tolerance. Although there is evidence for low effort capacity influencing symptoms and functional limitations in CFS, it is assumed that reduced effort tolerance might be the primary disturbance in CFS.

Diagnostic implications: Distinguishing low effort capacity and reduced effort tolerance may contribute to a refinement of current diagnostic criteria of CFS and the identification of subgroups.

Therapeutic implications: The above-mentioned distinction may make it possible to formulate a rationale for an effective implementation and adequate outcome evaluation of rehabilitation strategies in CFS.

Research implications: This new heuristic framework may inform future research aimed at disentangling the complex determination of impaired motor performance in CFS, as well as studies aimed at customizing treatment to different subtypes of patients.

In search of a new balance. Can high "action-proneness" in patients with chronic fatigue syndrome be changed by a multidisciplinary group treatment?

OBJECTIVE

The purpose of this study is to investigate changes in action-proneness (a cognitive and behavioral tendency toward direct action) after a multidisciplinary group intervention, including cognitive behaviour therapy (CBT) and graded exercise therapy (GET).

METHODS

Patients with chronic fatigue syndrome (n=62) completed three versions of a Dutch self-report questionnaire evaluating action-proneness retrospectively that is (1) before illness onset, (2) before treatment and (3) after treatment. Significant others (n=62) also gave their opinion about the patients' action-proneness at time points 1 and 2.

RESULTS

Premorbid action-proneness levels considerably dropped after illness onset. After treatment, action-proneness levels significantly increased again, although levels remained below premorbid levels.

CONCLUSION

High action-proneness retrospectively reported by CFS patients can be adaptively modified by a multidisciplinary group treatment including CBT and GET.