Tired of being inactive: a systematic literature review of physical activity, physiological exercise capacity and muscle strength in patients with chronic fatigue syndrome

Relationship between subjective and objective fatigue and sleep characteristics in individuals with anxiety and mood disorders: An exploratory study

OBJECTIVE

Fatigue and sleep disturbances are important symptoms of anxiety and mood disorders (AMD). Studies about the relationship between these variables usually rely on self-report assessments. Therefore, the aim of our exploratory study was to investigate the independent correlations between subjective and objective fatigue and sleep characteristics in individuals with AMD.

METHODS

In sum, 233 individuals with AMD attending a stress-related disorders day care unit (78.5 % females, mean age 39.0 years old) participated in a cross-sectional study. Participants completed the Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, Multidimensional Fatigue Inventory-20, and Pittsburgh Sleep Quality Index self-report questionnaires, as well as an exercise capacity workload test for assessing objective fatigue and polysomnography monitoring for evaluation of sleep structure.

RESULTS

In individuals with AMD, exercise capacity workload was associated with lower percent of stage 1 sleep (β = - 0.17, p = 0.006), REM latency (β = -0.13, p = 0.042), and wake after sleep onset (β = -0.12, p = 0.039). General fatigue was associated with a higher percent of body movements (β = 0.12, p = 0.047), as well as mental fatigue was associated with a higher percent of body movements (β = 0.13, p = 0.029), and a higher score on the PSQI (β = 0.21, p = 0.002).

CONCLUSIONS

Objective sleep characteristics were associated with objective assessment of fatigue, while subjective sleep quality was associated with subjectively assessed mental fatigue.

The effectiveness of activity pacing interventions for people with chronic fatigue syndrome: a systematic review and meta-analysis

PURPOSE

To investigate whether activity pacing interventions (alone or in conjunction with other evidence-based interventions) improve fatigue, physical function, psychological distress, depression, and anxiety in people with chronic fatigue syndrome (CFS).

MATERIALS AND METHODS

Seven databases were searched until 13 August 2022 for randomised controlled trials that included activity pacing interventions for CFS and a validated measure of fatigue. Secondary outcomes were physical function, psychological distress, depression, and anxiety. Two reviewers independently screened studies by title, abstract and full text. Methodological quality was evaluated using the PEDro scale. Random-effects meta-analyses were performed in R.

RESULTS

6390 articles were screened, with 14 included. Good overall study quality was supported by PEDro scale ratings. Activity pacing interventions were effective (Hedges' g (95% CI)) at reducing fatigue (-0.52 (-0.73 to -0.32)), psychological distress (-0.37 (-0.51 to -0.24)) and depression (-0.29 (-0.49 to -0.09)) and improving physical function (mean difference 7.18 (3.17-11.18)) when compared to no treatment/usual care. The extent of improvement was greater for interventions that encouraged graded escalation of physical activities and cognitive activities.

CONCLUSION

Activity pacing interventions are effective in reducing fatigue and psychological distress and improving physical function in CFS, particularly when people are encouraged to gradually increase activities.

REGISTRATION

PROSPERO CRD42016036087. IMPLICATIONS FOR REHABILITATIONA key feature of chronic fatigue syndrome (CFS) is a prolonged post-exertional exacerbation of symptoms following physical activities or cognitive activities.Activity pacing is a common strategy often embedded in multi-component management programs for CFS.Activity pacing interventions are effective in reducing fatigue and psychological distress and improving physical function in CFS, particularly when patients are encouraged to gradually increase their activities.Healthcare professionals embedding activity pacing as part of treatment should work collaboratively with patients to ensure successful, individualised self-management strategies.

Fibromyalgia and Chronic Fatigue Syndromes: A systematic review and meta-analysis of cardiorespiratory fitness and neuromuscular function compared with healthy individuals

OBJECTIVE

To determine cardiorespiratory fitness and neuromuscular function of people with CFS and FMS compared to healthy individuals.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Medline, CINAHL, AMED, Cochrane Central Register of Controlled Trials (CENTRAL), and PEDro from inception to June 2022.

ELIGIBLE CRITERIA FOR SELECTING STUDIES

Studies were included if presenting baseline data on cardiorespiratory fitness and/or neuromuscular function from observational or interventional studies of patients diagnosed with FMS or CFS. Participants were aged 18 years or older, with results also provided for healthy controls. Risk of bias assessment was conducted using the Quality Assessment Tool for Quantitative Studies (EPHPP).

RESULTS

99 studies including 9853 participants (5808 patients; 4405 healthy controls) met our eligibility criteria. Random effects meta-analysis showed lower cardiorespiratory fitness (VO2max, anaerobic threshold, peak lactate) and neuromuscular function (MVC, fatigability, voluntary activation, muscle volume, muscle mass, rate of perceived exertion) in CFS and FMS compared to controls: all with moderate to high effect sizes.

DISCUSSION

Our results demonstrate lower cardiorespiratory fitness and muscle function in those living with FMS or CFS when compared to controls. There were indications of dysregulated neuro-muscular interactions including heightened perceptions of effort, reduced ability to activate the available musculature during exercise and reduced tolerance of exercise.

TRAIL REGISTRATION

PROSPERO registration number: (CRD42020184108).

Application of Surface Electromyography in Exercise Fatigue: A Review

Exercise fatigue is a common physiological phenomenon in human activities. The occurrence of exercise fatigue can reduce human power output and exercise performance, and increased the risk of sports injuries. As physiological signals that are closely related to human activities, surface electromyography (sEMG) signals have been widely used in exercise fatigue assessment. Great advances have been made in the measurement and interpretation of electromyographic signals recorded on surfaces. It is a practical way to assess exercise fatigue with the use of electromyographic features. With the development of machine learning, the application of sEMG signals in human evaluation has been developed. In this article, we focused on sEMG signal processing, feature extraction, and classification in exercise fatigue. sEMG based multisource information fusion for exercise fatigue was also introduced. Finally, the development trend of exercise fatigue detection is prospected.

An exploratory study of discrepancies between objective and subjective measurement of the physical activity level in female patients with chronic fatigue syndrome

OBJECTIVE

To explore the ability of a self-report activity diary to measure the physical activity level (PAL) in female patients with chronic fatigue syndrome (CFS) and whether illness-related complaints, health-related quality of life domains (HRQOL) or demographic factors are associated with discrepancies between self-reported and objectively measured PAL.

METHODS

Sixty-six patients with CFS, recruited from the chronic fatigue clinic of a university hospital, and twenty matched healthy controls wore an accelerometer (Actical) for six consecutive days and registered their activities in an activity diary in the same period. Participants' demographic data was collected and all subjects completed the CFS Symptom List (illness-related complaints) daily and Short-Form-36 (HRQOL domains) during the first and second appointment.

RESULTS

A significant, but weak association between the activity diary and Actical was present in patients with CFS (r_s = 0.376 and r_s = 0.352; p < 0.001) and a moderately strong association in healthy controls (r_s = 0.605; and r_s = 0.644; p < 0.001) between week and weekend days, respectively. A linear mixed model identified a negative association between age and the discrepancy between the self-reported and objective measure of PA in both patients with CFS and healthy controls.

CONCLUSION

The activity diary showed limited ability to register the PAL in female patients with CFS. The discrepancy between measures was not explained by illness-related complaints, HRQOL domains or demographic factors. The activity diary cannot replace objective activity monitoring measured with an accelerometer, but may provide additional information about the perceived activity.

Chronic fatigue syndrome: Abnormally fast muscle fiber conduction in the membranes of motor units at low static force load

OBJECTIVE

Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are disorders of unknown etiology and unclear pathophysiology, with overlapping symptoms of - especially muscular -fatigue and pain. Studies have shown increased muscle fiber conduction velocity (CV) in the non-painful muscles of FM patients. We investigated whether CFS patients also show CV abnormalities.

METHODS

Females with CFS (n = 25), with FM (n = 22), and healthy controls (n = 21) underwent surface electromyography of the biceps brachii, loaded up to 20% of maximum strength, during short static contractions. The mean CV and motor unit potential (MUP) velocities with their statistical distribution were measured.

RESULTS

The CV changes with force differed between CFS-group and both FM-group and controls (P = 0.01). The CV of the CFS-group increased excessively with force (P < 0.001), whereas that of the controls increased only slightly and non-significantly, and that of the FM-group did not increase at all. In the CFS-group, the number of MUPs conveying very high conduction velocities increased abundantly with force and the MUPs narrowed.

CONCLUSION

Our results suggest disturbed muscle membrane function in CFS patients, in their motor units involved in low force generation. Central neural deregulation may contribute to this disturbance.

SIGNIFICANCE

These findings help to detangle the underlying mechanisms of CFS.

Patients' experiences and effects of non-pharmacological treatment for myalgic encephalomyelitis/chronic fatigue syndrome - a scoping mixed methods review

PURPOSE

The EU COST Action 15111 collaboration on myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) aims to assess current research and identify knowledge gaps in Europe. Presently, our purpose is to map the effects of non-pharmacological therapies (NPTs) for ME/CFS, and what patients find important in the treatment process.

METHODS

A scoping mixed methods literature review of European studies identified 16 papers fulfiling our inclusion criteria. The quantitative and qualitative studies were synthesized separately in tables. Additionally, extracts from the qualitative studies were subjected to translational analysis.

RESULTS

Effect studies addressed cognitive behavioural therapy (CBT, n = 4), multimodal rehabilitation (n = 2) and activity-pacing (n = 2). CBT reduced fatigue scores more than usual care or waiting list controls. The effects of rehabilitation and activity-pacing were inconsistent. The contents, assessment methods and effects of rehabilitation and activity pacing studies varied. For patients, health professionals' recognition of ME/CFS and support were crucial, but they expressed ambiguous experiences of what the NPTs entail.

CONCLUSIONS

Methodological differences make comparisons across NPTs impossible, and from a patient perspective the relevance of the specific contents of NPTs are unclear. Future well-designed studies should focus on developing NPTs tailored to patients' concerns and evaluation tools reflecting what is essential for patients.

Patterns of daytime physical activity in patients with chronic fatigue syndrome

OBJECTIVES

To classify patients with chronic fatigue syndrome (CFS) by pattern of physical activity and determine the clinical associations of each type.

METHODS

579 out of 641 participants with CFS from the PACE (Pacing, graded Activity, Cognitive behavioural therapy: a randomised Evaluation) trial wore an Actiwatch (accelerometer) for between 3 and 7 days before any trial treatments, which provided a measure of physical activity. Participants' activity was categorised into one of four patterns (pervasively inactive, pervasively active, boom and bust, or indeterminate) primarily using a priori definitions of activity. Clinical associations were sought with each group using an exploratory logistic regression with the indeterminate activity group being the reference group.

RESULTS

124 (21%) of the participants were classified as pervasively inactive, 65 (11%) as pervasively active, 172 (30%) showed a 'boom and bust' pattern of activity, and 218 (38%) had an indeterminate pattern. Pervasively inactive patients were more physically disabled, those in the pervasively active group were more anxious, and those in the boom and bust group had more sleep disturbance.

CONCLUSION

We were able to classify patients with CFS into groups by their daytime activity pattern. The different patterns of activity were associated with important clinical variables, suggesting that they might be helpful in determining prognosis and targeting treatments. These associations need replication.

Myalgic encephalomyelitis/chronic fatigue syndrome: From pathophysiological insights to novel therapeutic opportunities

Myalgic encephalomyelitis (ME) or chronic fatigue syndrome (CFS) is a common and disabling condition with a paucity of effective and evidence-based therapies, reflecting a major unmet need. Cognitive behavioural therapy and graded exercise are of modest benefit for only some ME/CFS patients, and many sufferers report aggravation of symptoms of fatigue with exercise. The presence of a multiplicity of pathophysiological abnormalities in at least the subgroup of people with ME/CFS diagnosed with the current international consensus "Fukuda" criteria, points to numerous potential therapeutic targets. Such abnormalities include extensive data showing that at least a subgroup has a pro-inflammatory state, increased oxidative and nitrosative stress, disruption of gut mucosal barriers and mitochondrial dysfunction together with dysregulated bioenergetics. In this paper, these pathways are summarised, and data regarding promising therapeutic options that target these pathways are highlighted; they include coenzyme Q₁₀, melatonin, curcumin, molecular hydrogen and N-acetylcysteine. These data are promising yet preliminary, suggesting hopeful avenues to address this major unmet burden of illness.

Assessing chronic fatigue syndrome: Self-reported physical functioning and correlations with physical testing

The pathophysiology of chronic fatigue syndrome (CFS) remains unclear; no biomarkers have thus far been identified or physical tests designed to underpin its diagnosis. Assessment mainly uses Fukuda's criteria and is based on the exclusion of symptoms related to other diseases/syndromes, subjective self-reporting, and outcomes of self-report questionnaires. In order to improve the baseline assessment and progress evaluation of individuals suspected of CFS and using an association-oriented research strategy and a cross-correlational design, this study investigates possible associations between the performance on two physical tests, i.e. 'Timed Loaded Standing' (TLS), assessing trunk-arm endurance, and the 'Stops Walking with Eyes Closed while performing a secondary Cognitive Task' (SWECCT), measuring impaired automaticity of gait, and the results of two self-report questionnaires, the Checklist Individual Strength (CIS, total score and fatigue subscale score) and the physical functioning and vitality subscales of the Short Form Health Survey (SF-36) to gauge the participants' subjective feelings of fatigue and beliefs regarding their abilities to perform daily-life activities. Comparisons of the outcomes obtained in 27 female patients with a confirmed diagnosis of CFS revealed that trunk-arm endurance as measured with the TLS correlated with the SF-36 physical functioning subscale only (raw p value: 0.004). None of the other correlations were statistically significant. It is concluded that the TLS may have potential as an objective assessment tool to support the diagnosis and monitoring of treatment effects in CFS.

Balance deficits in Chronic Fatigue Syndrome with and without fibromyalgia

OBJECTIVE

Chronic Fatigue Syndrome (CFS) is a disorder of unknown etiology associated with debilitating fatigue. One symptom commonly reported is disequilibrium. The goal of this study was to determine if CFS patients demonstrated verified balance deficits and if this was effected by comorbid fibromyalgia (FM).

METHODS

Twenty-seven patients with CFS (12 with comorbid FM) and 22 age and gender matched controls performed posturography.

RESULTS

Balance scores were significantly correlated with physical functional status in the CFS group (R2 = 0.43, P < 0.001), which was not found for mental functional status (R2 = 0.06, P > 0.5). CFS patients (regardless of FM) had significantly higher anxiety subscale of the vertigo symptom scale scores. CFS patients, regardless of FM status, demonstrated significantly lower overall composite balance scores (Controls - 78.8±1.5; CFS - 69.0±1.4, P < 0.005) even when controlling for anxiety and also had worse preference scores, indicating they relied on visual information preferentially even when visual information was incorrect. Interestingly, the CFS+FM group, not CFS only, demonstrated significantly worse vestibular scores (Controls - 70.2±2.4; CFS only - 67.9±3.8; CFS with FM - 55.4±4.6, P = 0.013).

INTERPRETATION

The major findings are that poor balance may be associated with poorer self-reported physical health. In addition, CFS patients seemed to rely preferentially on visual inputs, regardless of whether it was correct. The finding that vestibular function may be impaired in patients with CFS+FM but not in those with CFS alone suggests that the pathophysiology of CFS+FM may differ as has been suggested by some.

Fatigue Is Associated With Altered Monitoring and Preparation of Physical Effort in Patients With Chronic Fatigue Syndrome

BACKGROUND

Chronic fatigue syndrome (CFS) is characterized by disabling fatigue, which is suggested to be maintained by dysfunctional beliefs. Fatigue and its maintenance are recently conceptualized as arising from abnormally precise expectations about bodily inputs and from beliefs of diminished control over bodily states, respectively. This study used functional neuroimaging to identify the neural correlates of fatigue and its maintenance by beliefs during a physical effort task.

METHODS

We isolated behavioral adjustments and cerebral activity during feedback processing and motor preparation, in the context of a task in which patients with CFS (n = 85) and healthy control subjects (n = 29) produced 30%, 50%, and 70% of their right-hand maximal voluntary contraction, and received directional feedback on performance (e.g., too little force).

RESULTS

Patients with CSF showed an effort-dependent behavioral bias toward less effort investment in response to directional feedback for the highest effort level as compared with healthy control subjects. This bias was associated with reduced feedback-related activity in the dorsolateral prefrontal cortex. These effects were proportional to state-related fatigue and prior beliefs about CFS patients' ability to perform the task. Patients with CFS also showed higher activity in the supplementary motor area, proportional to their state-related fatigue, and reduced connectivity between the supplementary motor area and sensorimotor cortex during motor preparation as compared with control subjects.

CONCLUSIONS

These findings link fatigue symptoms to alterations in behavioral choices on effort investment, prefrontal functioning, and supplementary motor area connectivity, with the dorsolateral prefrontal cortex being associated with prior beliefs about physical abilities.

Mechanisms Explaining Muscle Fatigue and Muscle Pain in Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): a Review of Recent Findings

PURPOSE OF REVIEW

Here, we review potential causes of muscle dysfunction seen in many patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) such as the effects of oxidative and nitrosative stress (O&NS) and mitochondrial impairments together with reduced heat shock protein production and a range of metabolic abnormalities.

RECENT FINDINGS

Several studies published in the last few years have highlighted the existence of chronic O&NS, inflammation, impaired mitochondrial function and reduced heat shock protein production in many patients with ME/CFS. These studies have also highlighted the detrimental effects of chronically elevated O&NS on muscle functions such as reducing the time to muscle fatigue during exercise and impairing muscle contractility. Mechanisms have also been revealed by which chronic O&NS and or impaired heat shock production may impair muscle repair following exercise and indeed the adaptive responses in the striated muscle to acute and chronic increases in physical activity. The presence of chronic O&NS, low-grade inflammation and impaired heat shock protein production may well explain the objective findings of increased muscle fatigue, impaired contractility and multiple dimensions of exercise intolerance in many patients with ME/CFS.

Submaximal Exercise Capacity in Juvenile Dermatomyositis after Longterm Disease: The Contribution of Muscle, Lung, and Heart Involvement

OBJECTIVE

To compare submaximal exercise capacity in patients with juvenile dermatomyositis (JDM) with controls, and analyze contributions of muscle, heart, and lung impairment in patients.

METHODS

Fifty-nine patients with JDM, with a mean 16.9 years after symptom onset, and 59 sex- and age-matched controls completed a 6-min walk test (6MWT) and a timed up and go (TUG) test. Muscle function, disease activity/damage, and health-related quality of life (HRQOL) were assessed by validated tools; heart function by echocardiography and electrocardiography; and lung function by spirometry, DLCO, and body plethysmography. A thoracic high-resolution computed tomography (HRCT) scan and magnetic resonance imaging of the thighs were completed in patients.

RESULTS

The 6MWT distance (6MWD) was 592 ± 81 m in patients versus 649 ± 79 m in controls (p < 0.001), and 563 ± 75 m in active versus 622 ± 76 m in inactive JDM (p = 0.004). The TUG time was 13.1 ± 2.1 s in patients versus 12.3 ± 2.0 s in controls (p = 0.034), and 13.7 ± 2.2 s in active versus 12.5 ± 1.8 s in inactive JDM (p = 0.028). No statistically significant difference was found between inactive JDM and controls in either test. In patients, the Childhood Myositis Assessment Score influenced the 6MWD and TUG time the most, followed by a low DLCO and HRCT pathology in the 6MWT and forced vital capacity in the TUG test. Medical Outcomes Study Short Form-36 physical component summary correlated strongly with both tests.

CONCLUSION

Submaximal exercise capacity was reduced in patients with JDM, particularly those with active disease. This reduction was associated with muscle and lung dysfunction and poorer HRQOL.

Development of a recumbent isometric yoga program for patients with severe chronic fatigue syndrome/myalgic encephalomyelitis: A pilot study to assess feasibility and efficacy

Background

Our previous randomized controlled trial demonstrated that isometric yoga in a sitting position reduces fatigue in patients with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). However, some patients experience difficulties sitting or practicing isometric yoga in a sitting position for long periods. To date, therapeutic interventions for patients with severe symptoms have not been established. Therefore, we developed a recumbent isometric yoga program, which takes approximately 20 min to complete, designed to reduce fatigue in patients with severe CFS/ME. The aim of this pilot study was to assess the feasibility, safety, and usefulness of this program.

Methods

This pilot study included 12 adult patients with CFS/ME. Six patients were reluctant to practice isometric yoga in a sitting position because of the severity of their fatigue (group 1). The remaining six patients had previously practiced isometric yoga in a sitting position (group 2). For 3 months, the patients of both groups practiced recumbent isometric yoga every 2 to 4 weeks with a yoga instructor and at home on other days if they could. The short-term effects of isometric yoga on fatigue were assessed using the Profile of Mood Status (POMS) questionnaire immediately before and after their final session with the yoga instructor. The long-term effects of isometric yoga on fatigue were assessed using the Chalder Fatigue Scale (FS) questionnaire before and after the intervention period. Adverse events, satisfaction with the program, and preference of yoga position (sitting or recumbent) were also recorded.

Results

All subjects completed the intervention. In both groups, the POMS fatigue score was significantly decreased after practicing the 20-min yoga program and the Chalder FS score was decreased significantly after the 3-month intervention period. There were no serious adverse events. All subjects in group 2 preferred the recumbent isometric yoga program over a sitting yoga program.

Conclusions

This study suggests that recumbent isometric yoga is a feasible and acceptable treatment for patients with CFS/ME, even for patients who experience difficulty practicing isometric yoga in the sitting position.

Timed loaded standing in female chronic fatigue syndrome compared with other populations

Patients with chronic fatigue syndrome (CFS), like patients with osteoporosis, have similar difficulties in standing and sitting. The aim of the study was to compare combined trunk and arm endurance among women with CFS (n = 72), women with osteoporosis (n = 30), nondisabled women (n = 55), and women from non-industrialized countries (n = 58) using the timed loaded standing (TLS) test. TLS measures how long a person can hold a 1 kg dumbbell in each hand in front of him or her with straight arms. TLS was higher in the industrialized nondisabled population than in the non-industrialized study population (p < 0.001) and in patients with osteoporosis (p = 0.002). TLS was lower in patients with CFS than in nondisabled controls (p < 0.001). After adjusting for age, body height, and weight, combined trunk and arm endurance was lower in CFS patients than in osteoporotic patients, even though the patients with osteoporosis were more than 25 yr older (p < 0.001) [corrected]. In CFS, TLS was lower than in the non-industrialized group (p = 0.02). Since only women were studied, external validity of the results is limited to adult female patients with CFS. TLS revealed a specific biomechanical weakness in CFS patients that can be taken into account from the onset of a rehabilitation program. We propose that influencing the quality, rather than the quantity, of movement could be used in the rehabilitation.

Activity Pacing Self-Management in Chronic Fatigue Syndrome: A Randomized Controlled Trial

OBJECTIVE

To evaluate the effectiveness of an activity pacing self-management (APSM) intervention in improving performance of daily life activities in women with chronic fatigue syndrome (CFS).

METHOD

A total of 33 women with CFS (age 41.1±11.2 yr) were randomly allocated to APSM (experimental group; n=16) or relaxation (control group; n=17). Main outcome measures included the Canadian Occupational Performance Measure (COPM; primary) and Checklist Individual Strength (CIS).

RESULTS

COPM scores changed significantly over time in both groups (p=.03). The change in Satisfaction scores showed a significant difference in favor only of APSM (effect size=0.74 [0.11, 1.4]). CIS scores decreased significantly in the experimental group only (p<.01).

CONCLUSION

APSM was found to be feasible and effective in optimizing participation in desired daily life activities in women with CFS. Replication in a larger sample with long-term follow-up is required.

Investigating neural mechanisms of change of cognitive behavioural therapy for chronic fatigue syndrome: a randomized controlled trial

BACKGROUND

Chronic fatigue syndrome (CFS) is characterized by profound and disabling fatigue with no known somatic explanation. Cognitive behavioral therapy (CBT) has proven to be a successful intervention leading to a reduction in fatigue and disability. Based on previous neuroimaging findings, it has been suggested that central neural mechanisms may underlie CFS symptoms and play a role in the change brought on by CBT. In this randomized controlled trial we aim to further investigate the neural mechanisms that underlie fatigue in CFS and their change by CBT.

METHODS/DESIGN

We will conduct a randomized controlled trial in which we collect anatomical and functional magnetic resonance imaging (MRI) measures from female CFS patients before and after CBT (N = 60) or waiting list (N = 30) and compare these with measures from age and education matched healthy controls (N = 30). By including a large treatment group we will also be able to compare patients that benefit from CBT with those that do not. In addition, to further investigate the role of endocrine and immune biomarkers in CFS, we will determine cortisol and cytokine concentrations in blood, hair and/or saliva.

DISCUSSION

This project creates an unique opportunity to enhance our understanding of CFS symptoms and its change by CBT in terms of neuroanatomical, neurofunctional, endocrinological and immunological mechanisms and can help to further improve future treatments strategies.

TRIAL REGISTRATION

Dutch Trial Register #15852. Registered 9 December 2013 ( http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4311 ).

Submaximal exercise testing with near-infrared spectroscopy in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome patients compared to healthy controls: a case-control study

BACKGROUND

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating illness. Symptoms include profound fatigue and distinctive post-exertional malaise (PEM). We asked whether a submaximal exercise test would prove useful for identifying different patterns of tissue oxygen utilization in individuals with ME/CFS versus healthy subjects. Such a test has potential to aid with ME/CFS diagnosis, or to characterize patients' illness.

METHODS

A case-control study of 16 patients with ME/CFS compared to 16 healthy controls completing a 3-min handgrip protocol was performed. Response was measured using near-infrared spectroscopy, resulting in measurements of oxygenated (O2Hb) and deoxygenated hemoglobin (HHb) over wrist extensors and flexors. Changes in O2Hb (delta (d)O2Hb) and HHb (dHHb) absorbance between the first and last contraction were calculated, as were the force-time product of all contractions, measured as tension-time index (TTI), and ratings of perceived exertion (RPE).

RESULTS

Individuals with ME/CFS demonstrated smaller dO2Hb and dHHb than controls. However, after adjusting for TTI and change in total hemoglobin (delta (d)tHb), differences in dO2Hb and dHHb were reduced, with large overlapping variances. RPE was significantly higher for cases than controls, particularly at rest.

CONCLUSIONS

Relative to controls, participants with ME/CFS demonstrated higher RPE, lower TTI, and reduced dO2Hb and dHHb during repetitive handgrip exercise, although considerable variance was observed. With further study, submaximal exercise testing may prove useful for stratifying patients with a lower propensity for inducing PEM, and have the ability to establish baseline intensities for exercise prescription.

'I've Been Walking on Eggshells All My Life': Fibromyalgia Patients' Narratives About Experienced Violence and Abuse

According to earlier research, the prevalence of violence and abuse in the life history of patients with chronic widespread pain and fibromyalgia seems to be high in comparison with other pain patients and healthy controls. The purpose of the present study was to explore how experiences of violence and abuse are expressed and reflected on and how the causes and consequences of violence are interpreted by female patients with a long history of fibromyalgia. The data were drawn from narrative interviews of 11 women who had earlier participated in a fibromyalgia-specific rehabilitation course. The findings are presented through three main themes: loss of self-esteem, physical and mental bruises, and loss of womanhood. The onset of fibromyalgia was perceived as an inevitable result of physical or mental trauma. In conclusion, the narrated life stories indicated that violence is still hidden behind a wall of silence and non-interference in our society. The devastating mental and physical consequences of violence in different forms may be carried by the individual for years, even decades. Understanding any exposure to violence that a patient has endured may help healthcare professionals to understand the individual's health behaviour and any possible reluctance to undergo treatment and rehabilitation. Copyright © 2015 John Wiley & Sons, Ltd.

Rehabilitative therapies for chronic fatigue syndrome: a secondary mediation analysis of the PACE trial

BACKGROUND

Cognitive behaviour therapy (CBT) added to specialist medical care (SMC), or graded exercise therapy (GET) added to SMC, are more effective in reducing fatigue and improving physical function than both adaptive pacing therapy (APT) plus SMC and SMC alone for chronic fatigue syndrome. We investigate putative treatment mechanisms.

METHODS

We did a planned secondary mediation analysis of the PACE trial comparing SMC alone or SMC plus APT with SMC plus CBT and SMC plus GET for patients with chronic fatigue syndrome. 641 participants were recruited from six specialist chronic fatigue syndrome clinics in the UK National Health Service between March 18, 2005, and Nov 28, 2008. We assessed mediation using the product of coefficients method with the 12 week measure of the mediators and the 52 week measure of the outcomes. The primary outcomes were fatigue measured by the Chalder fatigue scale and physical function measured by the physical function subscale of the SF-36. We included confounder covariates and used treatment by mediator interaction terms to examine differences in mediator-outcome relations by treatment group.

FINDINGS

The largest mediated effect for both CBT and GET and both primary outcomes was through fear avoidance beliefs with an effect of larger magnitude for GET (standardised effects ×10, CBT vs APT, fatigue -1.22, 95% CI -0.52 to -1.97, physical function 1.54, 0.86 to 2.31; GET vs APT, fatigue -1.86, -0.80 to -2.89, physical function 2.35, 1.35 to 3.39). Increase in exercise tolerance (6 min walk distance) was a potent mediator of the effect of GET (vs APT, fatigue -1.37, 95% CI -0.76 to -2.21, physical function 1.90, 1.10 to 2.91), but not CBT.

INTERPRETATION

Our main finding was that fear avoidance beliefs were the strongest mediator for both CBT and GET. Changes in both beliefs and behaviour mediated the effects of both CBT and GET, but more so for GET. The results support a treatment model in which both beliefs and behaviour play a part in perpetuating fatigue and disability in chronic fatigue syndrome.

FUNDING

UK Medical Research Council, Department of Health for England, Scottish Chief Scientist Office, Department for Work and Pensions, National Institute for Health Research (NIHR), NIHR Biomedical Research Centre for Mental Health at South London and Maudsley NHS Foundation Trust, and Institute of Psychiatry, Psychology, and Neuroscience, King's College London.

Association between cognitive performance, physical fitness, and physical activity level in women with chronic fatigue syndrome

Limited scientific evidence suggests that physical activity is directly related to cognitive performance in patients with chronic fatigue syndrome (CFS). To date, no other study has examined the direct relationship between cognitive performance and physical fitness in these patients. This study examined whether cognitive performance and physical fitness are associated in female patients with CFS and investigated the association between cognitive performance and physical activity level (PAL) in the same study sample. We hypothesized that patients who performed better on cognitive tasks would show increased PALs and better performance on physical tests. The study included 31 women with CFS and 13 healthy inactive women. Participants first completed three cognitive tests. Afterward, they undertook a test to determine their maximal handgrip strength, performed a bicycle ergometer test, and were provided with an activity monitor. In patients with CFS, lower peak oxygen uptake and peak heart rate were associated with slower psychomotor speed (p < 0.05). Maximal handgrip strength was correlated with working memory performance (p < 0.05). Both choice and simple reaction time were lower in patients with CFS relative to healthy controls (p < 0.05 and p < 0.001, respectively). In conclusion, physical fitness, but not PAL, is associated with cognitive performance in female patients with CFS.

Short-term effect of aerobic exercise on symptoms in multiple sclerosis and chronic fatigue syndrome: a pilot study

BACKGROUND

This pilot study was conducted to determine whether a 15-minute bout of moderate-intensity aerobic cycling exercise would affect symptoms (pain and fatigue) and function (Timed 25-Foot Walk test [T25FW] and Timed Up and Go test [TUG]) in people with multiple sclerosis (MS) or chronic fatigue syndrome (CFS), and to compare these results with those of a healthy control group.

METHODS

Eight people with MS (Expanded Disability Status Scale score 5-6; Karnofsky score 50-80), eight people with CFS (Karnofsky score 50-80), and eight healthy volunteers participated in the study. Pain and fatigue levels and results of the T25FW and TUG were established at baseline as well as at 30 minutes, 2 hours, and 24 hours following a 15-minute stationary cycling aerobic exercise test. Repeated-measures analysis of variance (ANOVA) and covariance (ANCOVA) were used to analyze the findings over time.

RESULTS

At baseline there were statistically significant differences between groups in fatigue (P = .039), T25FW (P = .034), and TUG (P = .010). A significant group/time interaction emerged for fatigue levels (P= .005). We found no significant group/time interaction for pain levels or function.

CONCLUSIONS

Undertaking 15 minutes of moderate-intensity aerobic cycling exercise had no significant adverse effects on pain or function in people with MS and CFS (with a Karnofsky score of 50-80) within a 24-hour time period. These initial results suggest that people with MS or CFS may undertake 15 minutes of cycling as moderate aerobic exercise with no expected negative impact on pain or function.

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.

Three non-ambulatory adults with multiple disabilities exercise foot-leg movements through microswitch-aided programs

This study assessed the use of microswitch-aided programs to help three non-ambulatory adults with multiple disabilities exercise foot-leg responses. Those responses served to activate a largely neglected part of the participants' body, with possibly positive physical implications (e.g., for blood circulation, swelling, and muscle strength). Intervention focused on the left and right foot-leg response, separately. Eventually, sessions with one response were alternated with sessions with the other response. Responses were monitored via microswitches and followed by 8s of preferred stimulation (e.g., music and vibrotactile stimulation), which was automatically delivered. The results showed that all three participants had high levels of foot-leg responses during the intervention phases and a 3-week post-intervention check. The participants also displayed expressions of positive involvement during those study periods (i.e., engaged in behaviors, such as music-related head movements, smiles, or touching the vibratory devices) that could be interpreted as forms of interest/pleasure and happiness. These results are in line with previous findings in this area and can be taken as an important confirmation of the strength and dependability of the approach in motivating non-ambulatory persons with multiple disabilities to engage in foot-leg movements. The practical implications of these findings are discussed.

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.