Exercise therapy for chronic fatigue syndrome

Recovery from refractory chronic fatigue syndrome with CBT and modafinil

Many patients with chronic fatigue syndrome (CFS) fail to derive benefit from evidence-based treatments such as cognitive-behavioural therapy (CBT) and graded exercise therapy leading to permanent disability. To discover whether a repeat prescription of modafinil might potentiate the benefits of CBT leading to social recovery as defined by 2 or more point improvement in energy and muscular pain/concentration and return to work or full-time training. Three patients with treatment-resistant CFS (mean duration 17.66 years) treated with modafinil and CBT in a Liaison Psychiatry clinic were retrospectively reviewed. Progress was reviewed at baseline, 4-6 months and 10-24 months. Patients rated their fatigue, pain and concentration using 10-point Likert scales. 2/3 achieved clinically meaningful improvements in energy and pain/concentration and 3/3 achieved social recovery. Modafinil, when prescribed over the medium term, would appear to be a potentially useful potentiating agent when added to CBT.

Emotion dysregulation, fatigue, and electronic cigarette expectancies

Emotion dysregulation and the experience of fatigue have both been linked to the maintenance of substance use. However, limited empirical data has evaluated individual differences in these constructs in terms of e-cigarette use expectancies. The present study examined a theoretically relevant model focused on whether the experience of more severe fatigue explains, in part, the relation between individual differences in emotion dysregulation and positive and negative e-cigarette expectancies among 525 adult e-cigarette users (50.9% female, Mage = 35.25 years, SD = 10.10). It was hypothesized that emotion dysregulation, via fatigue severity, would significantly predict greater positive and negative e-cigarette expectancies, which was examined in two separate mediation models. Fatigue severity significantly explained, in part, the relation between emotion dysregulation and positive (b = 0.02, CI [0.01, 0.02]) and negative expectancies of e-cigarette use (b = 0.02, 95% CI [0.02, 0.03]). The current findings suggest that the experience of fatigue helps explain the relation between emotion dysregulation and positive and negative e-cigarette expectancies among adult e-cigarette users. Future work is needed to explicate how reducing fatigue severity in the context of emotion dysregulation may change expectancies about e-cigarette expectancies.

The explanatory role of fatigue severity in the relation between COVID-19 perceived stress and depression, anxiety, and panic severity

The COVID-19 pandemic has had an adverse effect on anxiety and depression symptoms and disorders in the United States and worldwide. As such, there is considerable interest in better understanding the relationship between COVID-19 and anxiety and depressive disorders. Although individual differences in perceived stress have shown to be related to anxiety and depression in non-COVID-19 work, research has not examined potential factors underlying this relation in the context of COVID-19. Fatigue severity may be a promising mechanistic construct for perceived stress and anxiety and depression relations, as some work has found that perceived stress may predict elevated fatigue symptoms. As such, the current study sought to examine the potential explanatory role of fatigue severity in the relation between COVID-19 specific perceived stress and depression, anxiety, and panic symptoms among 563 adults (41.9% female, M_age = 38.26 years, SD = 12.15). Results suggested that COVID-19 perceived stress, via fatigue severity, significantly predicted depression, anxiety, and panic symptoms. These results provide initial empirical support for the role of fatigue severity in the relation between COVID-19 perceived stress and depression, anxiety, and panic symptoms. Future work would benefit from using longitudinal data to evaluate the current model.

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.

Exercise-induced pain threshold modulation in healthy subjects: a systematic review and meta-analysis

Background

The use of exercise is a potential treatment option to modulate pain (exercise-induced hypoalgesia). The pain threshold (PT) response is a measure of pain sensitivity that may be a useful marker to assess the effect of physical exercise on pain modulation.

Aim

The aim of this systematic review and meta-analysis is to evaluate the PT response to exercise in healthy subjects.

Methods

We searched in MEDLINE, EMBASE, Web of Science, Lilacs, and Scopus using a search strategy with the following search terms: "exercise" OR "physical activity" AND "Pain Threshold" from inception to December 2nd, 2019. As criteria for inclusion of appropriate studies: randomized controlled trials or quasi-experimental studies that enrolled healthy subjects; performed an exercise intervention; assessed PT. Hedge's effect sizes of PT response and their 95% confidence intervals were calculated, and random-effects meta-analyses were performed.

Results

For the final analysis, thirty-six studies were included (n=1326). From this we found a significant and homogenous increase in PT in healthy subjects (ES=0.19, 95% CI= 0.11 to 0.27, I2=7.5%). According to subgroup analysis the effect was higher in studies: with women (ES=0.36); performing strength exercise (ES=0.34), and with moderate intensity (ES=0.27), and no differences by age were found. Confirmed by the meta-regression analysis.

Conclusion

This meta-analysis provides evidence of small to moderate effects of exercise on PT in healthy subjects, being even higher for moderate strength exercise and in women. These results support the idea of modulation of the endogenous pain system due to exercise and highlight the need of clinical translation to chronic pain population.

Effects of an Individualized Exercise Program Plus Behavioral Change Enhancement Strategies for Managing Fatigue in Older People Who Are Frail: Protocol for a Cluster Randomized Controlled Trial

BACKGROUND

Although the evidence suggests that general fatigue is a strong indicator of rapid aging, frailty, and disability, general fatigue is undertreated in gerontological care.

OBJECTIVE

The aim of this study is to investigate whether an individualized exercise program with and without behavioral change enhancement (BCE) strategies for older people who are frail and have general fatigue will reduce their fatigue and symptoms of frailty.

DESIGN

A 3-arm, single-blind, cluster randomized controlled trial registered with ClinicalTrials.gov (NCT03394495) will be conducted.

SETTING

The study will be conducted in a community setting.

PARTICIPANTS

Two hundred eighty-five community-dwelling older people with general fatigue will be recruited from 12 district community health centers.

INTERVENTION

People from each center will be randomized to one of three groups. The combined group will receive a 16-week combined intervention consisting of individualized exercise training and the BCE program, plus two booster sessions at 2 and 6 months after the program. The exercise group will receive exercise training and health talks only. The control group will receive health talks only.

MEASUREMENTS

Outcome measures will be collected at baseline, at the midpoint (week 8) of the program, and then at 1 week, 6 months, and 12 months after the end of the program. The primary outcome---level of fatigue---will be measured using the Multidimensional Fatigue Inventory. Secondary outcomes will include the participants' frailty status, strength, mobility, exercise self-efficacy, and habitual physical activity.

LIMITATIONS

A self-reported level of fatigue will be used.

CONCLUSIONS

The effect of exercise and BCE strategies on general fatigue among older people who are frail is not known. This study will be a pioneering interventional study on how general fatigue among older people who are frail can be managed and how fatigue-related frailty can be prevented or minimized.

Exercise therapy for chronic fatigue syndrome

Editorial Note

A statement from the Editor in Chief about this review and its planned update is available here: https://www.cochrane.org/news/cfs

BACKGROUND

Chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME) is a serious disorder characterised by persistent postexertional fatigue and substantial symptoms related to cognitive, immune and autonomous dysfunction. There is no specific diagnostic test, therefore diagnostic criteria are used to diagnose CFS. The prevalence of CFS varies by type of diagnostic criteria used. Existing treatment strategies primarily aim to relieve symptoms and improve function. One treatment option is exercise therapy.

OBJECTIVES

The objective of this review was to determine the effects of exercise therapy for adults with CFS compared with any other intervention or control on fatigue, adverse outcomes, pain, physical functioning, quality of life, mood disorders, sleep, self-perceived changes in overall health, health service resources use and dropout.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Group controlled trials register, CENTRAL, and SPORTDiscus up to May 2014, using a comprehensive list of free-text terms for CFS and exercise. We located unpublished and ongoing studies through the World Health Organization International Clinical Trials Registry Platform up to May 2014. We screened reference lists of retrieved articles and contacted experts in the field for additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) about adults with a primary diagnosis of CFS, from all diagnostic criteria, who were able to participate in exercise therapy.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessments and data extraction. We combined continuous measures of outcomes using mean differences (MDs) or standardised mean differences (SMDs). To facilitate interpretation of SMDs, we re-expressed SMD estimates as MDs on more common measurement scales. We combined dichotomous outcomes using risk ratios (RRs). We assessed the certainty of evidence using GRADE.

MAIN RESULTS

We included eight RCTs with data from 1518 participants.Exercise therapy lasted from 12 weeks to 26 weeks. The studies measured effect at the end of the treatment and at long-term follow-up, after 50 weeks or 72 weeks.Seven studies used aerobic exercise therapies such as walking, swimming, cycling or dancing, provided at mixed levels in terms of intensity of the aerobic exercise from very low to quite rigorous, and one study used anaerobic exercise. Control groups consisted of passive control, including treatment as usual, relaxation or flexibility (eight studies); cognitive behavioural therapy (CBT) (two studies); cognitive therapy (one study); supportive listening (one study); pacing (one study); pharmacological treatment (one study) and combination treatment (one study).Most studies had a low risk of selection bias. All had a high risk of performance and detection bias.Exercise therapy compared with 'passive' controlExercise therapy probably reduces fatigue at end of treatment (SMD -0.66, 95% CI -1.01 to -0.31; 7 studies, 840 participants; moderate-certainty evidence; re-expressed MD -3.4, 95% CI -5.3 to -1.6; scale 0 to 33). We are uncertain if fatigue is reduced in the long term because the certainty of the evidence is very low (SMD -0.62, 95 % CI -1.32 to 0.07; 4 studies, 670 participants; re-expressed MD -3.2, 95% CI -6.9 to 0.4; scale 0 to 33).We are uncertain about the risk of serious adverse reactions because the certainty of the evidence is very low (RR 0.99, 95% CI 0.14 to 6.97; 1 study, 319 participants).Exercise therapy may moderately improve physical functioning at end of treatment, but the long-term effect is uncertain because the certainty of the evidence is very low. Exercise therapy may also slightly improve sleep at end of treatment and at long term. The effect of exercise therapy on pain, quality of life and depression is uncertain because evidence is missing or of very low certainty.Exercise therapy compared with CBTExercise therapy may make little or no difference to fatigue at end of treatment (MD 0.20, 95% CI -1.49 to 1.89; 1 study, 298 participants; low-certainty evidence), or at long-term follow-up (SMD 0.07, 95% CI -0.13 to 0.28; 2 studies, 351 participants; moderate-certainty evidence).We are uncertain about the risk of serious adverse reactions because the certainty of the evidence is very low (RR 0.67, 95% CI 0.11 to 3.96; 1 study, 321 participants).The available evidence suggests that there may be little or no difference between exercise therapy and CBT in physical functioning or sleep (low-certainty evidence) and probably little or no difference in the effect on depression (moderate-certainty evidence). We are uncertain if exercise therapy compared to CBT improves quality of life or reduces pain because the evidence is of very low certainty.Exercise therapy compared with adaptive pacingExercise therapy may slightly reduce fatigue at end of treatment (MD -2.00, 95% CI -3.57 to -0.43; scale 0 to 33; 1 study, 305 participants; low-certainty evidence) and at long-term follow-up (MD -2.50, 95% CI -4.16 to -0.84; scale 0 to 33; 1 study, 307 participants; low-certainty evidence).We are uncertain about the risk of serious adverse reactions (RR 0.99, 95% CI 0.14 to 6.97; 1 study, 319 participants; very low-certainty evidence).The available evidence suggests that exercise therapy may slightly improve physical functioning, depression and sleep compared to adaptive pacing (low-certainty evidence). No studies reported quality of life or pain.Exercise therapy compared with antidepressantsWe are uncertain if exercise therapy, alone or in combination with antidepressants, reduces fatigue and depression more than antidepressant alone, as the certainty of the evidence is very low. The one included study did not report on adverse reactions, pain, physical functioning, quality of life, sleep or long-term results.

AUTHORS' CONCLUSIONS

Exercise therapy probably has a positive effect on fatigue in adults with CFS compared to usual care or passive therapies. The evidence regarding adverse effects is uncertain. Due to limited evidence it is difficult to draw conclusions about the comparative effectiveness of CBT, adaptive pacing or other interventions. All studies were conducted with outpatients diagnosed with 1994 criteria of the Centers for Disease Control and Prevention or the Oxford criteria, or both. Patients diagnosed using other criteria may experience different effects.

The PACE trial of treatments for chronic fatigue syndrome: a response to WILSHIRE et al

Chronic Fatigue Syndrome (CFS) is chronic disabling illness characterized by severe disabling fatigue, typically made worse by exertion. Myalgic Encephalomyelitis (ME) is thought by some to be the same disorder (then referred to as CFS/ME) and by others to be different. There is an urgent need to find effective treatments for CFS. The UK Medical Research Council PACE trial published in 2011 compared available treatments and concluded that when added to specialist medical care, cognitive behaviour therapy and graded exercise therapy were more effective in improving both fatigue and physical function in participants with CFS, than both adaptive pacing therapy and specialised medical care alone. In this paper, we respond to the methodological criticisms of the trial and a reanalysis of the trial data reported by Wilshire at al. We conclude that neither the criticisms nor the reanalysis offer any convincing reason to change the conclusions of the PACE trial.

Exercise-induced hypoalgesia: A meta-analysis of exercise dosing for the treatment of chronic pain

OBJECTIVE

Increasing evidence purports exercise as a first-line therapeutic for the treatment of nearly all forms of chronic pain. However, knowledge of efficacious dosing respective to treatment modality and pain condition is virtually absent in the literature. The purpose of this analysis was to calculate the extent to which exercise treatment shows dose-dependent effects similar to what is seen with pharmacological treatments.

METHODS

A recently published comprehensive review of exercise and physical activity for chronic pain in adults was identified in May 2017. This report reviewed different physical activity and exercise interventions and their effectiveness in reducing pain severity and found overall modest effects of exercise in the treatment of pain. We analyzed this existing data set, focusing specifically on the dose of exercise intervention in these studies. We re-analyzed data from 75 studies looking at benefits of time of exercising per week, frequency of exercise per week, duration of intervention (in weeks), and estimated intensity of exercise.

RESULTS

Analysis revealed a significant positive correlation with exercise duration and analgesic effect on neck pain. Multiple linear regression modeling of these data predicted that increasing the frequency of exercise sessions per week is most likely to have a positive effect on chronic pain patients.

DISCUSSION

Modest effects were observed with one significant correlation between duration and pain effect for neck pain. Overall, these results provide insufficient evidence to conclude the presence of a strong dose effect of exercise in pain, but our modeling data provide tes predictions that can be used to design future studies to explicitly test the question of dose in specific patient populations.

Interdisciplinary Screening, Diagnosis, Therapy and Follow-up of Breast Cancer. Guideline of the DGGG and the DKG (S3-Level, AWMF Registry Number 032/045OL, December 2017) - Part 1 with Recommendations for the Screening, Diagnosis and Therapy of Breast Cancer

Purpose The aim of this official guideline coordinated and published by the German Society for Gynecology and Obstetrics (DGGG) and the German Cancer Society (DKG) was to optimize the screening, diagnosis, therapy and follow-up care of breast cancer. Methods The process of updating the S3 guideline dating from 2012 was based on the adaptation of identified source guidelines which were combined with reviews of evidence compiled using PICO (Patients/Interventions/Control/Outcome) questions and the results of a systematic search of literature databases and the selection and evaluation of the identified literature. The interdisciplinary working groups took the identified materials as their starting point to develop recommendations and statements which were modified and graded in a structured consensus procedure. Recommendations Part 1 of this short version of the guideline presents recommendations for the screening, diagnosis and follow-up care of breast cancer. The importance of mammography for screening is confirmed in this updated version of the guideline and forms the basis for all screening. In addition to the conventional methods used to diagnose breast cancer, computed tomography (CT) is recommended for staging in women with a higher risk of recurrence. The follow-up concept includes suggested intervals between physical, ultrasound and mammography examinations, additional high-tech diagnostic procedures, and the determination of tumor markers for the evaluation of metastatic disease.

Management of Functional Somatic Syndromes and Bodily Distress

Functional somatic syndromes (FSS), like irritable bowel syndrome or fibromyalgia and other symptoms reflecting bodily distress, are common in practically all areas of medicine worldwide. Diagnostic and therapeutic approaches to these symptoms and syndromes vary substantially across and within medical specialties from biomedicine to psychiatry. Patients may become frustrated with the lack of effective treatment, doctors may experience these disorders as difficult to treat, and this type of health problem forms an important component of the global burden of disease. This review intends to develop a unifying perspective on the understanding and management of FSS and bodily distress. Firstly, we present the clinical problem and review current concepts for classification. Secondly, we propose an integrated etiological model which encompasses a wide range of biopsychosocial vulnerability and triggering factors and considers consecutive aggravating and maintaining factors. Thirdly, we systematically scrutinize the current evidence base in terms of an umbrella review of systematic reviews from 2007 to 2017 and give recommendations for treatment for all levels of care, concentrating on developments over the last 10 years. We conclude that activating, patient-involving, and centrally acting therapies appear to be more effective than passive ones that primarily act on peripheral physiology, and we recommend stepped care approaches that translate a truly biopsychosocial approach into actual management of the patient.

Earlier time to aerobic exercise is associated with faster recovery following acute sport concussion

Objective

To determine whether earlier time to initiation of aerobic exercise following acute concussion is associated with time to full return to (1) sport and (2) school or work.

Methods

A retrospective stratified propensity score survival analysis of acute (≤14 days) concussion was used to determine whether time (days) to initiation of aerobic exercise post-concussion was associated with, both, time (days) to full return to (1) sport and (2) school or work.

Results

A total of 253 acute concussions [median (IQR) age, 17.0 (15.0–20.0) years; 148 (58.5%) males] were included in this study. Multivariate Cox regression models identified that earlier time to aerobic exercise was associated with faster return to sport and school/work adjusting for other covariates, including quintile propensity strata. For each successive day in delay to initiation of aerobic exercise, individuals had a less favourable recovery trajectory. Initiating aerobic exercise at 3 and 7 days following injury was associated with a respective 36.5% (HR, 0.63; 95% CI, 0.53–0.76) and 73.2% (HR, 0.27; 95% CI, 0.16–0.45) reduced probability of faster full return to sport compared to within 1 day; and a respective 45.9% (HR, 0.54; 95% CI, 0.44–0.66) and 83.1% (HR, 0.17; 95% CI, 0.10–0.30) reduced probability of faster full return to school/work. Additionally, concussion history, symptom severity, LOC deleteriously influenced concussion recovery.

Conclusion

Earlier initiation of aerobic exercise was associated with faster full return to sport and school or work. This study provides greater insight into the benefits and safety of aerobic exercise within the first week of the injury.

A 4-Day Mindfulness-Based Cognitive Behavioral Intervention Program for CFS/ME. An Open Study, With 1-Year Follow-Up

Background: Chronic Fatigue Syndrome/Myalgic Encephalopathy (CFS/ME) is an incapacitating illness in which single treatment interventions seem to have variable effects. Based on an earlier study we have conducted a new study with a concentrated intervention program. The aims of this study were to: (1) explore the clinical course for patients with CFS/ME who participated in a treatment program delivered during four consecutive days, and (2) evaluate their satisfaction with this program. Methods: 305 patients diagnosed with CFS/ME (Oxford criteria), recruited from a clinical population referred to a specialist outpatient clinic, participated in an open uncontrolled study of the clinical course through 1 year. The study group participated in a 4-day group intervention program, comprised by education, cognitive group therapy sessions, mindfulness sessions, physical activity and writing sessions, within a context of cognitive behavioral therapy, mindfulness, acceptance and commitment model. Assessments were done by self-reports prior to the first consultation, 1 week before and 1 week after the intervention program, and at 3 months and 1 year after the intervention. SPSS 23 and R 3.3 were used for statistical analyses. The associations between case definitions and the outcome measures (Chalder Fatigue Scale (FS), Short Form 36 (SF-36) physical functioning scale) were assessed by a linear mixed effects model (LME). Results: Results showed statistically significant clinical changes for 80% of the patients after the intervention, changes being sustained through 1 year after the program. For both Fatigue Scale (FS) and the SF-36 there were statistically significant effects of time from baseline to all time points with a statistically significant drop in scores, applying the linear mixed effects model. A subgroup fulfilling the inclusion criteria from the PACE study (Chalder Fatigue Scale >6/11, SF-36 Physical functioning <65/100) showed clinically significant improvement through 1 year, changes in outcome measures were statistically significant (p < 0.001). None of the patients included in the program dropped out, and a great majority of patients expressed high satisfaction with the content, focus and amount of treatment. Conclusion: Clinical changes observed from pre-treatment to 1 year follow-up could represent effects of the 4-day concentrated intervention program, and should be further explored in a controlled study.

Effect of Acute Exercise on Fatigue in People with ME/CFS/SEID: A Meta-analysis

PURPOSE

A prominent symptom of myalgic encephalomyelitis, chronic fatigue syndrome, or systemic exertion intolerance disease (ME/CFS/SEID) is persistent fatigue that is worsened by physical exertion. Here the population effect of a single bout of exercise on fatigue symptoms in people with ME/CFS/SEID was estimated and effect moderators were identified.

METHODS

Google Scholar was systematically searched for peer-reviewed articles published between February 1991 and May 2015. Studies were included where people diagnosed with ME/CFS/SEID and matched control participants completed a single bout of exercise and fatigue self-reports were obtained before and after exercise. Fatigue means, standard deviations, and sample sizes were extracted to calculate effect sizes and the 95% confidence interval. Effects were pooled using a random-effects model and corrected for small sample bias to generate mean Δ. Multilevel regression modeling adjusted for nesting of effects within studies. Moderators identified a priori were diagnostic criteria, fibromyalgia comorbidity, exercise factors (intensity, duration, and type), and measurement factors.

RESULTS

Seven studies examining 159 people with ME/CFS/SEID met inclusion criteria, and 47 fatigue effects were derived. The mean fatigue effect was Δ = 0.73 (95% confidence interval = 0.24-1.23). Fatigue increases were larger for people with ME/CFS/SEID when fatigue was measured 4 h or more after exercise ended rather than during or immediately after exercise ceased.

CONCLUSIONS

This preliminary evidence indicates that acute exercise increases fatigue in people with ME/CFS/SEID more than that in control groups, but effects were heterogeneous between studies. Future studies with no-exercise control groups of people with ME/CFS/SEID are needed to obtain a more precise estimate of the effect of exercise on fatigue in this population.

Exercise therapy for chronic fatigue syndrome

BACKGROUND

Chronic fatigue syndrome (CFS) is characterised by persistent, medically unexplained fatigue, as well as symptoms such as musculoskeletal pain, sleep disturbance, headaches and impaired concentration and short-term memory. CFS presents as a common, debilitating and serious health problem. Treatment may include physical interventions, such as exercise therapy, which was last reviewed in 2004.

OBJECTIVES

The objective of this review was to determine the effects of exercise therapy (ET) for patients with CFS as compared with any other intervention or control.• Exercise therapy versus 'passive control' (e.g. treatment as usual, waiting-list control, relaxation, flexibility).• Exercise therapy versus other active treatment (e.g. cognitive-behavioural therapy (CBT), cognitive treatment, supportive therapy, pacing, pharmacological therapy such as antidepressants).• Exercise therapy in combination with other specified treatment strategies versus other specified treatment strategies (e.g. exercise combined with pharmacological treatment vs pharmacological treatment alone).

SEARCH METHODS

We searched The Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register (CCDANCTR), the Cochrane Central Register of Controlled Trials (CENTRAL) and SPORTDiscus up to May 2014 using a comprehensive list of free-text terms for CFS and exercise. We located unpublished or ongoing trials through the World Health Organization (WHO) International Clinical Trials Registry Platform (to May 2014). We screened reference lists of retrieved articles and contacted experts in the field for additional studies SELECTION CRITERIA: Randomised controlled trials involving adults with a primary diagnosis of CFS who were able to participate in exercise therapy. Studies had to compare exercise therapy with passive control, psychological therapies, adaptive pacing therapy or pharmacological therapy.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessments and data extraction. We combined continuous measures of outcomes using mean differences (MDs) and standardised mean differences (SMDs). We combined serious adverse reactions and drop-outs using risk ratios (RRs). We calculated an overall effect size with 95% confidence intervals (CIs) for each outcome.

MAIN RESULTS

We have included eight randomised controlled studies and have reported data from 1518 participants in this review. Three studies diagnosed individuals with CFS using the 1994 criteria of the Centers for Disease Control and Prevention (CDC); five used the Oxford criteria. Exercise therapy lasted from 12 to 26 weeks. Seven studies used variations of aerobic exercise therapy such as walking, swimming, cycling or dancing provided at mixed levels in terms of intensity of the aerobic exercise from very low to quite rigorous, whilst one study used anaerobic exercise. Control groups consisted of passive control (eight studies; e.g. treatment as usual, relaxation, flexibility) or CBT (two studies), cognitive therapy (one study), supportive listening (one study), pacing (one study), pharmacological treatment (one study) and combination treatment (one study). Risk of bias varied across studies, but within each study, little variation was found in the risk of bias across our primary and secondary outcome measures.Investigators compared exercise therapy with 'passive' control in eight trials, which enrolled 971 participants. Seven studies consistently showed a reduction in fatigue following exercise therapy at end of treatment, even though the fatigue scales used different scoring systems: an 11-item scale with a scoring system of 0 to 11 points (MD -6.06, 95% CI -6.95 to -5.17; one study, 148 participants; low-quality evidence); the same 11-item scale with a scoring system of 0 to 33 points (MD -2.82, 95% CI -4.07 to -1.57; three studies, 540 participants; moderate-quality evidence); and a 14-item scale with a scoring system of 0 to 42 points (MD -6.80, 95% CI -10.31 to -3.28; three studies, 152 participants; moderate-quality evidence). Serious adverse reactions were rare in both groups (RR 0.99, 95% CI 0.14 to 6.97; one study, 319 participants; moderate-quality evidence), but sparse data made it impossible for review authors to draw conclusions. Study authors reported a positive effect of exercise therapy at end of treatment with respect to sleep (MD -1.49, 95% CI -2.95 to -0.02; two studies, 323 participants), physical functioning (MD 13.10, 95% CI 1.98 to 24.22; five studies, 725 participants) and self-perceived changes in overall health (RR 1.83, 95% CI 1.39 to 2.40; four studies, 489 participants). It was not possible for review authors to draw conclusions regarding the remaining outcomes.Investigators compared exercise therapy with CBT in two trials (351 participants). One trial (298 participants) reported little or no difference in fatigue at end of treatment between the two groups using an 11-item scale with a scoring system of 0 to 33 points (MD 0.20, 95% CI -1.49 to 1.89). Both studies measured differences in fatigue at follow-up, but neither found differences between the two groups using an 11-item fatigue scale with a scoring system of 0 to 33 points (MD 0.30, 95% CI -1.45 to 2.05) and a nine-item Fatigue Severity Scale with a scoring system of 1 to 7 points (MD 0.40, 95% CI -0.34 to 1.14). Serious adverse reactions were rare in both groups (RR 0.67, 95% CI 0.11 to 3.96). We observed little or no difference in physical functioning, depression, anxiety and sleep, and we were not able to draw any conclusions with regard to pain, self-perceived changes in overall health, use of health service resources and drop-out rate.With regard to other comparisons, one study (320 participants) suggested a general benefit of exercise over adaptive pacing, and another study (183 participants) a benefit of exercise over supportive listening. The available evidence was too sparse to draw conclusions about the effect of pharmaceutical interventions.

AUTHORS' CONCLUSIONS

Patients with CFS may generally benefit and feel less fatigued following exercise therapy, and no evidence suggests that exercise therapy may worsen outcomes. A positive effect with respect to sleep, physical function and self-perceived general health has been observed, but no conclusions for the outcomes of pain, quality of life, anxiety, depression, drop-out rate and health service resources were possible. The effectiveness of exercise therapy seems greater than that of pacing but similar to that of CBT. Randomised trials with low risk of bias are needed to investigate the type, duration and intensity of the most beneficial exercise intervention.

Heart rate variability biofeedback therapy and graded exercise training in management of chronic fatigue syndrome: An exploratory pilot study

OBJECTIVE

Chronic fatigue syndrome (CFS) is characterised by persistent fatigue, exhaustion, and several physical complaints. Research has shown cognitive behavioural therapy (CBT) and graded exercise training (GET) to be the most effective treatments. In a first step we aimed to assess the efficacy of heart rate variability biofeedback therapy (HRV-BF) as a treatment method comprising cognitive and behavioural strategies and GET in the pilot trial. In a second step we aimed to compare both interventions with regard to specific parameters.

METHODS

The study was conducted in an outpatient treatment setting. A total of 28 women with CFS (50.3±9.3years) were randomly assigned to receive either eight sessions of HRV-BF or GET. The primary outcome was fatigue severity. Secondary outcomes were mental and physical quality of life and depression. Data were collected before and after the intervention as well as at a 5-month follow-up.

RESULTS

General fatigue improved significantly after both HRV-BF and GET. Specific cognitive components of fatigue, mental quality of life, and depression improved significantly after HRV-BF only. Physical quality of life improved significantly after GET. There were significant differences between groups regarding mental quality of life and depression favouring HRV-BF.

CONCLUSION

Both interventions reduce fatigue. HRV-BF seems to have additional effects on components of mental health, including depression, whereas GET seems to emphasise components of physical health. These data offer implications for further research on combining HRV-BF and GET in patients with CFS.

TRIAL REGISTRATION

The described trial has been registered at the International Clinical Trials Registry Platform following the number DRKS00005445.

Treatment and management of chronic fatigue syndrome/myalgic encephalomyelitis: all roads lead to Rome

This review explores the current evidence on benefits and harms of therapeutic interventions in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) and makes recommendations. CFS/ME is a complex, multi-system, chronic medical condition whose pathophysiology remains unknown. No established diagnostic tests exist nor are any FDA-approved drugs available for treatment. Because of the range of symptoms of CFS/ME, treatment approaches vary widely. Studies undertaken have heterogeneous designs and are limited by sample size, length of follow-up, applicability and methodological quality. The use of rintatolimod and rituximab as well as counselling, behavioural and rehabilitation therapy programs may be of benefit for CFS/ME, but the evidence of their effectiveness is still limited. Similarly, adaptive pacing appears to offer some benefits, but the results are debatable: so is the use of nutritional supplements, which may be of value to CFS/ME patients with biochemically proven deficiencies. To summarize, the recommended treatment strategies should include proper administration of nutritional supplements in CFS/ME patients with demonstrated deficiencies and personalized pacing programs to relieve symptoms and improve performance of daily activities, but a larger randomized controlled trial (RCT) evaluation is required to confirm these preliminary observations. At present, no firm conclusions can be drawn because the few RCTs undertaken to date have been small-scale, with a high risk of bias, and have used different case definitions. Further, RCTs are now urgently needed with rigorous experimental designs and appropriate data analysis, focusing particularly on the comparison of outcomes measures according to clinical presentation, patient characteristics, case criteria and degree of disability (i.e. severely ill ME cases or bedridden).

Response to the editorial by Dr Geraghty

This article is written in response to the linked editorial by Dr Geraghty about the adaptive Pacing, graded Activity and Cognitive behaviour therapy; a randomised Evaluation (PACE) trial, which we led, implemented and published. The PACE trial compared four treatments for people diagnosed with chronic fatigue syndrome. All participants in the trial received specialist medical care. The trial found that adding cognitive behaviour therapy or graded exercise therapy to specialist medical care was as safe as, and more effective than, adding adaptive pacing therapy or specialist medical care alone. Dr Geraghty has challenged these findings. In this article, we suggest that Dr Geraghty’s views are based on misunderstandings and misrepresentations of the PACE trial; these are corrected.

Exercise therapy for chronic fatigue syndrome

BACKGROUND

Chronic fatigue syndrome (CFS) is characterised by persistent, medically unexplained fatigue, as well as symptoms such as musculoskeletal pain, sleep disturbance, headaches and impaired concentration and short-term memory. CFS presents as a common, debilitating and serious health problem. Treatment may include physical interventions, such as exercise therapy, which was last reviewed in 2004.

OBJECTIVES

The objective of this review was to determine the effects of exercise therapy (ET) for patients with CFS as compared with any other intervention or control.• Exercise therapy versus 'passive control' (e.g. treatment as usual, waiting-list control, relaxation, flexibility).• Exercise therapy versus other active treatment (e.g. cognitive-behavioural therapy (CBT), cognitive treatment, supportive therapy, pacing, pharmacological therapy such as antidepressants).• Exercise therapy in combination with other specified treatment strategies versus other specified treatment strategies (e.g. exercise combined with pharmacological treatment vs pharmacological treatment alone).

SEARCH METHODS

We searched The Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register (CCDANCTR), the Cochrane Central Register of Controlled Trials (CENTRAL) and SPORTDiscus up to May 2014 using a comprehensive list of free-text terms for CFS and exercise. We located unpublished or ongoing trials through the World Health Organization (WHO) International Clinical Trials Registry Platform (to May 2014). We screened reference lists of retrieved articles and contacted experts in the field for additional studies SELECTION CRITERIA: Randomised controlled trials involving adults with a primary diagnosis of CFS who were able to participate in exercise therapy. Studies had to compare exercise therapy with passive control, psychological therapies, adaptive pacing therapy or pharmacological therapy.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessments and data extraction. We combined continuous measures of outcomes using mean differences (MDs) and standardised mean differences (SMDs). We combined serious adverse reactions and drop-outs using risk ratios (RRs). We calculated an overall effect size with 95% confidence intervals (CIs) for each outcome.

MAIN RESULTS

We have included eight randomised controlled studies and have reported data from 1518 participants in this review. Three studies diagnosed individuals with CFS using the 1994 criteria of the Centers for Disease Control and Prevention (CDC); five used the Oxford criteria. Exercise therapy lasted from 12 to 26 weeks. Seven studies used variations of aerobic exercise therapy such as walking, swimming, cycling or dancing provided at mixed levels in terms of intensity of the aerobic exercise from very low to quite rigorous, whilst one study used anaerobic exercise. Control groups consisted of passive control (eight studies; e.g. treatment as usual, relaxation, flexibility) or CBT (two studies), cognitive therapy (one study), supportive listening (one study), pacing (one study), pharmacological treatment (one study) and combination treatment (one study). Risk of bias varied across studies, but within each study, little variation was found in the risk of bias across our primary and secondary outcome measures.Investigators compared exercise therapy with 'passive' control in eight trials, which enrolled 971 participants. Seven studies consistently showed a reduction in fatigue following exercise therapy at end of treatment, even though the fatigue scales used different scoring systems: an 11-item scale with a scoring system of 0 to 11 points (MD -6.06, 95% CI -6.95 to -5.17; one study, 148 participants; low-quality evidence); the same 11-item scale with a scoring system of 0 to 33 points (MD -2.82, 95% CI -4.07 to -1.57; three studies, 540 participants; moderate-quality evidence); and a 14-item scale with a scoring system of 0 to 42 points (MD -6.80, 95% CI -10.31 to -3.28; three studies, 152 participants; moderate-quality evidence). Serious adverse reactions were rare in both groups (RR 0.99, 95% CI 0.14 to 6.97; one study, 319 participants; moderate-quality evidence), but sparse data made it impossible for review authors to draw conclusions. Study authors reported a positive effect of exercise therapy at end of treatment with respect to sleep (MD -1.49, 95% CI -2.95 to -0.02; two studies, 323 participants), physical functioning (MD 13.10, 95% CI 1.98 to 24.22; five studies, 725 participants) and self-perceived changes in overall health (RR 1.83, 95% CI 1.39 to 2.40; four studies, 489 participants). It was not possible for review authors to draw conclusions regarding the remaining outcomes.Investigators compared exercise therapy with CBT in two trials (351 participants). One trial (298 participants) reported little or no difference in fatigue at end of treatment between the two groups using an 11-item scale with a scoring system of 0 to 33 points (MD 0.20, 95% CI -1.49 to 1.89). Both studies measured differences in fatigue at follow-up, but neither found differences between the two groups using an 11-item fatigue scale with a scoring system of 0 to 33 points (MD 0.30, 95% CI -1.45 to 2.05) and a nine-item Fatigue Severity Scale with a scoring system of 1 to 7 points (MD 0.40, 95% CI -0.34 to 1.14). Serious adverse reactions were rare in both groups (RR 0.67, 95% CI 0.11 to 3.96). We observed little or no difference in physical functioning, depression, anxiety and sleep, and we were not able to draw any conclusions with regard to pain, self-perceived changes in overall health, use of health service resources and drop-out rate.With regard to other comparisons, one study (320 participants) suggested a general benefit of exercise over adaptive pacing, and another study (183 participants) a benefit of exercise over supportive listening. The available evidence was too sparse to draw conclusions about the effect of pharmaceutical interventions.

AUTHORS' CONCLUSIONS

Patients with CFS may generally benefit and feel less fatigued following exercise therapy, and no evidence suggests that exercise therapy may worsen outcomes. A positive effect with respect to sleep, physical function and self-perceived general health has been observed, but no conclusions for the outcomes of pain, quality of life, anxiety, depression, drop-out rate and health service resources were possible. The effectiveness of exercise therapy seems greater than that of pacing but similar to that of CBT. Randomised trials with low risk of bias are needed to investigate the type, duration and intensity of the most beneficial exercise intervention.

High-Intensity Swimming Exercise Decreases Glutamate-Induced Nociception by Activation of G-Protein-Coupled Receptors Inhibiting Phosphorylated Protein Kinase A

Several studies in humans have reported that improved pain control is associated with exercise in a variety of painful conditions, including osteoarthritis, fibromyalgia, and neuropathic pain. Despite the growing amount of experimental data on physical exercise and nociception, the precise mechanisms through which high-intensity exercise reduces pain remain elusive. Since the glutamatergic system plays a major role in pain transmission, we firstly analyzed if physical exercise could be able to decrease glutamate-induced nociception through G-protein-coupled receptor (G-PCR) activation. The second purpose of this study was to examine the effect of exercising upon phosphorylation of protein kinase A (PKA) isoforms induced by intraplantar (i.pl.) glutamate injection in mice. Our results demonstrate that high-intensity swimming exercise decreases nociception induced by glutamate and that i.pl. or intrathecal injections of cannabinoid, opioid, and adenosine receptor antagonists, AM281, naloxone, and 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), respectively, prevent this effect. Furthermore, the peripheral A₁ and opioid receptors, but not CB₁, are also involved in exercise's effect. We also verified that glutamate injection increases levels of phosphorylated PKA (p-PKA). High-intensity swimming exercise significantly prevented p-PKA increase. The current data show the direct involvement of the glutamatergic system on the hyponociceptive effect of high-intensity swimming exercise as well as demonstrate that physical exercise can activate multiple intracellular pathways through G-PCR activation, which share the same endogenous mechanism, i.e., inhibition of p-PKA.

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

Objective: To evaluate the outcome of a multidisciplinary treatment programme for patients with chronic fatigue syndrome, including health-related quality of life (HRQoL) and psychosocial variables, and exercise capacity measures.

Design: A six-month prospective outcome study.

Setting: University outpatient rehabilitation clinic; group setting.

Subjects: One hundred and sixteen women fulfilling chronic fatigue syndrome criteria.

Interventions: Cognitive behaviourally and graded exercise-based strategies; emphasis on adaptive lifestyle changes.

Measures: Short Form General Health Survey (SF-36); Symptom Checklist (SCL-90); Causal Attribution List (CAL); Self-Efficacy Scale (SE); maximum progressive bicycle ergometer test with respiratory gas analysis; and isokinetic leg strength test, before and after treatment.

Results: The total group significantly improved on nearly all reported HRQoL/ psychosocial variables. Changes in exercise capacity measures were rather modest and did not correlate or only weakly correlated with HRQoL/psychosocial variables. Subgroup analyses indicated that less fit patients improved significantly more on exercise capacity measures than their more fit counterparts. Patients who were fitter at baseline scored better on pretreatment HRQoL/psychosocial variables, but both subgroups improved similarly on these variables.

Conclusions: Health-related quality of life and psychosocial functioning in patients with chronic fatigue syndrome improves after a six-month cognitive behaviourally and graded exercise-based multidisciplinary treatment programme. Increase in exercise capacity measures is not a necessary condition for reported improvements, except for less fit patients.

Design of the Park-in-Shape study: a phase II double blind randomized controlled trial evaluating the effects of exercise on motor and non-motor symptoms in Parkinson's disease

Background

Parkinson’s disease (PD) is a neurodegenerative disorder with a wide range of motor and non-motor symptoms. Despite optimal medical management, PD still results in a high disability rate and secondary complications and many patients lead a sedentary lifestyle, which in turn is also associated with a higher co-morbidity and mortality. Exercise has been explored as a strategy to reduce secondary complications and results suggests that it not only provides general health benefits, but may also provide symptomatic relief. If this holds true exercise would be a very attractive addition to the therapeutic arsenal in PD. The supportive evidence remains incomplete. Here, we describe the design of the Park-in-Shape study, which primarily aims to evaluate whether aerobic exercise affords clinically relevant improvements in motor symptoms in sedentary PD patients. A specific new element is the introduction of gaming to optimize compliance to the exercise intervention.

Methods/Design

The Park-in-Shape study is a randomized controlled, assessor- and patient-blinded single center study. Two parallel groups will include a total of 130 patients, receiving either aerobic exercise on a home trainer equipped with gaming elements (“exergaming”), or a non-aerobic intervention (stretching, flexibility and relaxation exercises). Both groups are supported by a specifically designed motivational app that uses gaming elements to stimulate patients to exercise and rewards them after having completed the exercise. Both interventions are delivered at home at least 3 times a week for 30–45 minutes during 6 months. Eligible patients are community-dwelling, sedentary patients diagnosed with mild-moderate PD. The primary outcome is the MDS-UPDRS motor score (tested in the off state) after 6 months. Secondary outcomes include various motor and non-motor symptoms, quality of life, physical fitness, and adherence.

Discussion

This Park-in-Shape study is anticipated to answer the question whether high intensity aerobic exercise combined with gaming elements (“exergaming”) provides symptomatic relief in PD. Strong elements include the double-blinded randomized controlled trial design, the MDS-UPDRS as valid primary outcome, the large sample size and unique combination of home-based pure aerobic exercise combined with gaming elements and motivational aspects.

Trial registration

Dutch trial register NTR4743

Qigong exercise alleviates fatigue, anxiety, and depressive symptoms, improves sleep quality, and shortens sleep latency in persons with chronic fatigue syndrome-like illness

Objectives. To evaluate the effectiveness of Baduanjin Qigong exercise on sleep, fatigue, anxiety, and depressive symptoms in chronic fatigue syndrome- (CFS-) like illness and to determine the dose-response relationship. Methods. One hundred fifty participants with CFS-like illness (mean age = 39.0, SD = 7.9) were randomly assigned to Qigong and waitlist. Sixteen 1.5-hour Qigong lessons were arranged over 9 consecutive weeks. Pittsburgh Sleep Quality Index (PSQI), Chalder Fatigue Scale (ChFS), and Hospital Anxiety and Depression Scale (HADS) were assessed at baseline, immediate posttreatment, and 3-month posttreatment. The amount of Qigong self-practice was assessed by self-report. Results. Repeated measures analyses of covariance showed a marginally nonsignificant (P = 0.064) group by time interaction in the PSQI total score, but it was significant for the “subjective sleep quality” and “sleep latency” items, favoring Qigong exercise. Improvement in “subjective sleep quality” was maintained at 3-month posttreatment. Significant group by time interaction was also detected for the ChFS and HADS anxiety and depression scores. The number of Qigong lessons attended and the amount of Qigong self-practice were significantly associated with sleep, fatigue, anxiety, and depressive symptom improvement. Conclusion. Baduanjin Qigong was an efficacious and acceptable treatment for sleep disturbance in CFS-like illness. This trial is registered with Hong Kong Clinical Trial Register: HKCTR-1380.

Interventions for fatigue in peripheral neuropathy

BACKGROUND

Persistent feelings of fatigue (or subjective fatigue), which may be experienced in the absence of physiological factors, affect many people with peripheral neuropathy. A variety of interventions for subjective fatigue are available, but little is known about their efficacy or the likelihood of any adverse effects for people with peripheral neuropathy.

OBJECTIVES

To assess the effects of drugs and physical, psychological or behavioural interventions for fatigue in adults or children with peripheral neuropathy.

SEARCH METHODS

On 5 November 2013, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE, EMBASE, CINAHL Plus, LILACS and AMED. We also searched reference lists of all studies identified for inclusion and relevant reviews, and contacted the authors of included studies and known experts in the field to identify additional published or unpublished data. We also searched trials registries for ongoing studies.

SELECTION CRITERIA

We considered for inclusion randomised controlled trials (RCTs) and quasi-RCTs comparing any form of intervention for fatigue management in adults with peripheral neuropathy with placebo, no intervention or an alternative form of intervention for fatigue. Interventions considered included drugs, pacing and grading of physical activity, general or specific exercise, compensatory strategies such as orthotics, relaxation, counselling, cognitive and educational strategies.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed risk of bias and extracted study data. We contacted study authors for additional information. We collected information on adverse events from the included trials.

MAIN RESULTS

The review includes three trials, which were all at low risk of bias, involving 530 people with peripheral neuropathy. The effects of amantadine from one randomised, double-blind, placebo-controlled, cross-over trial comparing amantadine with placebo for the treatment of fatigue in 80 people with Guillain-Barré syndrome (GBS) were uncertain for the proportion of people achieving a favourable outcome six weeks post-intervention (odds ratio (OR) 0.56 (95% confidence interval (CI) 0.22 to 1.35, N = 74, P = 0.16). We assessed the quality of this evidence as low. Two parallel-group randomised double-blind, placebo-controlled trials comparing the effects of two doses of ascorbic acid with placebo for reducing fatigue in adults with Charcot-Marie-Tooth disease type 1A (CMT1A) showed that the effects of ascorbic acid at either dose are probably small (standardised mean difference (SMD) -0.12 (95% CI -0.32 to 0.08, n = 404, P = 0.25)) for change in fatigue after 12 to 24 months (moderate quality evidence). Neither ascorbic acid study measured fatigue at four to 12 weeks, which was our primary outcome measure. No serious adverse events were reported with amantadine. Serious adverse events were reported in the trials of ascorbic acid. However,risk of serious adverse events was similar with ascorbic acid and placebo.

AUTHORS' CONCLUSIONS

One small imprecise study in people with GBS showed uncertain effects of amantadine on fatigue. In two studies in people with CMT1A there is moderate-quality evidence that ascorbic acid has little meaningful benefit on fatigue. Information about adverse effects was limited, although both treatments appear to be well tolerated and safe in these conditions.There was no evidence available from RCTs to evaluate the effect of other drugs or other interventions for fatigue in either GBS, CMT1A or other causes of peripheral neuropathy. The cost effectiveness of different interventions should also be considered in future randomised clinical trials.

Non-pharmacological interventions for somatoform disorders and medically unexplained physical symptoms (MUPS) in adults

BACKGROUND

Medically unexplained physical symptoms (MUPS) are physical symptoms for which no adequate medical explanation can be found after proper examination. The presence of MUPS is the key feature of conditions known as 'somatoform disorders'. Various psychological and physical therapies have been developed to treat somatoform disorders and MUPS. Although there are several reviews on non-pharmacological interventions for somatoform disorders and MUPS, a complete overview of the whole spectrum is missing.

OBJECTIVES

To assess the effects of non-pharmacological interventions for somatoform disorders (specifically somatisation disorder, undifferentiated somatoform disorder, somatoform disorders unspecified, somatoform autonomic dysfunction, pain disorder, and alternative somatoform diagnoses proposed in the literature) and MUPS in adults, in comparison with treatment as usual, waiting list controls, attention placebo, psychological placebo, enhanced or structured care, and other psychological or physical therapies.

SEARCH METHODS

We searched the Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Register (CCDANCTR) to November 2013. This register includes relevant randomised controlled trials (RCTs) from The Cochrane Library, EMBASE, MEDLINE, and PsycINFO. We ran an additional search on the Cochrane Central Register of Controlled Trials and a cited reference search on the Web of Science. We also searched grey literature, conference proceedings, international trial registers, and relevant systematic reviews.

SELECTION CRITERIA

We included RCTs and cluster randomised controlled trials which involved adults primarily diagnosed with a somatoform disorder or an alternative diagnostic concept of MUPS, who were assigned to a non-pharmacological intervention compared with usual care, waiting list controls, attention or psychological placebo, enhanced care, or another psychological or physical therapy intervention, alone or in combination.

DATA COLLECTION AND ANALYSIS

Four review authors, working in pairs, conducted data extraction and assessment of risk of bias. We resolved disagreements through discussion or consultation with another review author. We pooled data from studies addressing the same comparison using standardised mean differences (SMD) or risk ratios (RR) and a random-effects model. Primary outcomes were severity of somatic symptoms and acceptability of treatment.

MAIN RESULTS

We included 21 studies with 2658 randomised participants. All studies assessed the effectiveness of some form of psychological therapy. We found no studies that included physical therapy.Fourteen studies evaluated forms of cognitive behavioural therapy (CBT); the remainder evaluated behaviour therapies, third-wave CBT (mindfulness), psychodynamic therapies, and integrative therapy. Fifteen included studies compared the studied psychological therapy with usual care or a waiting list. Five studies compared the intervention to enhanced or structured care. Only one study compared cognitive behavioural therapy with behaviour therapy.Across the 21 studies, the mean number of sessions ranged from one to 13, over a period of one day to nine months. Duration of follow-up varied between two weeks and 24 months. Participants were recruited from various healthcare settings and the open population. Duration of symptoms, reported by nine studies, was at least several years, suggesting most participants had chronic symptoms at baseline.Due to the nature of the intervention, lack of blinding of participants, therapists, and outcome assessors resulted in a high risk of bias on these items for most studies. Eleven studies (52% of studies) reported a loss to follow-up of more than 20%. For other items, most studies were at low risk of bias. Adverse events were seldom reported.For all studies comparing some form of psychological therapy with usual care or a waiting list that could be included in the meta-analysis, the psychological therapy resulted in less severe symptoms at end of treatment (SMD -0.34; 95% confidence interval (CI) -0.53 to -0.16; 10 studies, 1081 analysed participants). This effect was considered small to medium; heterogeneity was moderate and overall quality of the evidence was low. Compared with usual care, psychological therapies resulted in a 7% higher proportion of drop-outs during treatment (RR acceptability 0.93; 95% CI 0.88 to 0.99; 14 studies, 1644 participants; moderate-quality evidence). Removing one outlier study reduced the difference to 5%. Results for the subgroup of studies comparing CBT with usual care were similar to those in the whole group.Five studies (624 analysed participants) assessed symptom severity comparing some psychological therapy with enhanced care, and found no clear evidence of a difference at end of treatment (pooled SMD -0.19; 95% CI -0.43 to 0.04; considerable heterogeneity; low-quality evidence). Five studies (679 participants) showed that psychological therapies were somewhat less acceptable in terms of drop-outs than enhanced care (RR 0.93; 95% CI 0.87 to 1.00; moderate-quality evidence).

AUTHORS' CONCLUSIONS

When all psychological therapies included this review were combined they were superior to usual care or waiting list in terms of reduction of symptom severity, but effect sizes were small. As a single treatment, only CBT has been adequately studied to allow tentative conclusions for practice to be drawn. Compared with usual care or waiting list conditions, CBT reduced somatic symptoms, with a small effect and substantial differences in effects between CBT studies. The effects were durable within and after one year of follow-up. Compared with enhanced or structured care, psychological therapies generally were not more effective for most of the outcomes. Compared with enhanced care, CBT was not more effective. The overall quality of evidence contributing to this review was rated low to moderate.The intervention groups reported no major harms. However, as most studies did not describe adverse events as an explicit outcome measure, this result has to be interpreted with caution.An important issue was that all studies in this review included participants who were willing to receive psychological treatment. In daily practice, there is also a substantial proportion of participants not willing to accept psychological treatments for somatoform disorders or MUPS. It is unclear how large this group is and how this influences the relevance of CBT in clinical practice.The number of studies investigating various treatment modalities (other than CBT) needs to be increased; this is especially relevant for studies concerning physical therapies. Future studies should include participants from a variety of age groups; they should also make efforts to blind outcome assessors and to conduct follow-up assessments until at least one year after the end of treatment.

Pilot study investigating the utility of a specialized online symptom management program for individuals with myalgic encephalomyelitis/chronic fatigue syndrome as compared to an online meditation program

Background

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a long-term, debilitating condition that impacts numerous areas of individuals’ lives. The two predominant treatment options for ME/CFS are cognitive behavioral therapy and graded exercise therapy; however, many people have found these techniques unacceptable or even damaging. This pilot study aimed to evaluate the utility of a specialized online symptom management program for ME/CFS in comparison to an online meditation program in an effort to ascertain whether this tool could be a further option for those with ME/CFS.

Methods

This experimental design consisted of two interventions: a specialized online symptoms management program (N=19) and a control intervention based on an online meditation website (N=9). A battery of questionnaires, including measures of multidimensional fatigue, illness-specific symptoms, perceived control, and mindful awareness, were completed before the participants commenced use of the programs and following 8 weeks’ use.

Results

Significant differences were found in the areas of chance and powerful others’ locus of control, and sleeping difficulties, but not in ME/CFS symptomatology overall.

Conclusion

The specialized online program described in this study warrants further investigation, as it appears to influence perceived control and key ME/CFS symptoms over time.

Several submaximal exercise tests are reliable, valid and acceptable in people with chronic pain, fibromyalgia or chronic fatigue: a systematic review

QUESTION

Are submaximal and maximal exercise tests reliable, valid and acceptable in people with chronic pain, fibromyalgia and fatigue disorders?

DESIGN

Systematic review of studies of the psychometric properties of exercise tests.

PARTICIPANTS

People older than 18 years with chronic pain, fibromyalgia and chronic fatigue disorders.

INTERVENTION

Studies of the measurement properties of tests of physical capacity in people with chronic pain, fibromyalgia or chronic fatigue disorders were included.

OUTCOME MEASURES

Studies were required to report: reliability coefficients (intraclass correlation coefficient, alpha reliability coefficient, limits of agreements and Bland-Altman plots); validity coefficients (intraclass correlation coefficient, Spearman's correlation, Kendal T coefficient, Pearson's correlation); or dropout rates.

RESULTS

Fourteen studies were eligible: none had low risk of bias, 10 had unclear risk of bias and four had high risk of bias. The included studies evaluated: Åstrand test; modified Åstrand test; Lean body mass-based Åstrand test; submaximal bicycle ergometer test following another protocol other than Åstrand test; 2-km walk test; 5-minute, 6-minute and 10-minute walk tests; shuttle walk test; and modified symptom-limited Bruce treadmill test. None of the studies assessed maximal exercise tests. Where they had been tested, reliability and validity were generally high. Dropout rates were generally acceptable. The 2-km walk test was not recommended in fibromyalgia.

CONCLUSION

Moderate evidence was found for reliability, validity and acceptability of submaximal exercise tests in patients with chronic pain, fibromyalgia or chronic fatigue. There is no evidence about maximal exercise tests in patients with chronic pain, fibromyalgia and chronic fatigue.

Traditional Chinese medicine for chronic fatigue syndrome: a systematic review of randomized clinical trials

BACKGROUND

There is no curative treatment for chronic fatigue syndrome (CFS). Traditional Chinese medicine (TCM) is widely used in the treatment of CFS in China.

OBJECTIVE

To evaluate the effectiveness and safety of TCM for CFS.

METHODS

The protocol of this review is registered at PROSPERO. We searched six main databases for randomized clinical trials (RCTs) on TCM for CFS from their inception to September 2013. The Cochrane risk of bias tool was used to assess the methodological quality. We used RevMan 5.1 to synthesize the results.

RESULTS

23 RCTs involving 1776 participants were identified. The risk of bias of the included studies was high. The types of TCM interventions varied, including Chinese herbal medicine, acupuncture, qigong, moxibustion, and acupoint application. The results of meta-analyses and several individual studies showed that TCM alone or in combination with other interventions significantly alleviated fatigue symptoms as measured by Chalder's fatigue scale, fatigue severity scale, fatigue assessment instrument by Joseph E. Schwartz, Bell's fatigue scale, and guiding principle of clinical research on new drugs of TCM for fatigue symptom. There was no enough evidence that TCM could improve the quality of life for CFS patients. The included studies did not report serious adverse events.

CONCLUSIONS

TCM appears to be effective to alleviate the fatigue symptom for people with CFS. However, due to the high risk of bias of the included studies, larger, well-designed studies are needed to confirm the potential benefit in the future.

The Metacognitions about Symptoms Control Scale: Development and Concurrent Validity

OBJECTIVE

This paper presents the development and preliminary validation of a self-report instrument designed to measure metacognitions pertaining to symptoms control in the form of the following: (1) symptoms focusing and (2) symptoms conceptual thinking.

METHODS

A total of 124 patients (95 female and 29 male) presenting with chronic fatigue syndrome (CFS) contributed data to the study to test the structure and psychometric properties of the Metacognitions about Symptoms Control Scale (MaSCS).

RESULTS

A principal components factor analysis indicated that a two-factor solution best fitted the data. The factors were labelled positive and negative metacognitions about symptoms control. Further analyses revealed that both factors had good internal consistency. Correlation analyses established preliminary concurrent validity, indicating that both positive and negative metacognitions about symptoms control were significantly associated with levels of fatigue in CFS. Regression analysis revealed that positive and negative metacognitions about symptoms control significantly predicted fatigue severity when controlling for anxiety and depression.

CONCLUSIONS

The newly developed instrument may help future research that examines the role of metacognitions in CFS, as well as aiding clinical assessment and case formulation.

KEY PRACTITIONER MESSAGE

The MaSCS is a useful first instrument to assess metacognitions in CFS. The MaSCS may help to deepen our understanding of symptoms control (symptoms focusing and conceptual thinking about symptoms) in the experience of CFS symptoms. Assessing and conceptualizing symptoms control through the MaSCS may aid treatment of CFS.

Chronic fatigue syndrome and personality: a case-control study using the Alternative Five Factor Model

Neuroticism is the personality dimension most frequently associated with chronic fatigue syndrome (CFS). Most studies have also shown that CFS patients are less extraverted than non-CFS patients, but results have been inconsistent, possibly because the facets of the extraversion dimension have not been separately analyzed. This study has the following aims: to assess the personality profile of adults with CFS using the Alternative Five-Factor Model (AFFM), which considers Activity and Sociability as two separate factors of Extraversion, and to test the discriminant validity of a measure of the AFFM, the Zuckerman-Kuhlman Personality Questionnaire, in differentiating CFS subjects from normal-range matched controls. The CFS sample consisted of 132 consecutive patients referred for persistent fatigue or pain to the Department of Medicine of a university hospital. These were compared with 132 matched normal population controls. Significantly lower levels of Activity and significantly higher levels of Neuroticism-Anxiety best discriminated CFS patients from controls. The results are consistent with existing data on the relationship between Neuroticism and CFS, and clarify the relationship between Extraversion and CFS by providing new data on the relationship of Activity to CFS.

Pain in chronic fatigue syndrome: response to rehabilitative treatments in the PACE trial

BACKGROUND

Pain is a common symptom of chronic fatigue syndrome (CFS). We investigated the effects of the treatments used in the PACE trial [cognitive behavioural therapy (CBT), graded exercise therapy (GET), adaptive pacing therapy (APT) and specialist medical care (SMC)] on pain in CFS.

METHOD

We compared pain outcomes including individual painful symptoms, taken from the CDC criteria for CFS and co-morbid fibromyalgia. We modelled outcomes adjusting for baseline variables with multiple linear regression.

RESULTS

Significantly less frequent muscle pain was reported by patients following treatment with CBT compared to SMC (mean difference = 0.38 unit change in frequency, p = 0.02), GET versus SMC (0.42, p = 0.01) and GET versus APT (0.37, p = 0.01). Significantly less joint pain was reported following CBT versus APT (0.35, p = 0.02) and GET versus APT (0.36, p = 0.02). Co-morbid fibromyalgia was less frequent following GET versus SMC (0.03, p = 0.03). The effect sizes of these differences varied between 0.25 and 0.31 for muscle pain and 0.24 and 0.26 for joint pain. Treatment effects on pain were independent of 'change in fatigue'.

CONCLUSIONS

CBT and GET were more effective in reducing the frequency of both muscle and joint pain than APT and SMC. When compared to SMC, GET also reduced the frequency of co-morbid fibromyalgia; the size of this effect on pain was small.

Adolescent fatigue, POTS, and recovery: a guide for clinicians

Many teenagers who struggle with chronic fatigue have symptoms suggestive of autonomic dysfunction that may include lightheadedness, headaches, palpitations, nausea, and abdominal pain. Inadequate sleep habits and psychological conditions can contribute to fatigue, as can concurrent medical conditions. One type of autonomic dysfunction, postural orthostatic tachycardia syndrome, is increasingly being identified in adolescents with its constellation of fatigue, orthostatic intolerance, and excessive postural tachycardia (more than 40 beats/min). A family-based approach to care with support from a multidisciplinary team can diagnose, treat, educate, and encourage patients. Full recovery is possible with multi-faceted treatment. The daily treatment plan should consist of increased fluid and salt intake, aerobic exercise, and regular sleep and meal schedules; some medications can be helpful. Psychological support is critical and often includes biobehavioral strategies and cognitive-behavioral therapy to help with symptom management. More intensive recovery plans can be implemented when necessary.

Severe fatigue in patients with adrenal insufficiency: physical, psychosocial and endocrine determinants

BACKGROUND

Fatigue is a frequently experienced complaint in patients with adrenal insufficiency (AI) and may be influenced by cortisol levels.

AIM

The objective of this study was to determine the prevalence of severe fatigue in adrenal insufficiency (AI) patients, to assess which dimensions contribute to fatigue severity and to determine the association between salivary cortisol levels and momentary fatigue.

SUBJECTS AND METHODS

We performed a cross-sectional study in the outpatient department of a university hospital. Included were 27 patients with congenital adrenal hyperplasia (CAH), 26 patients with primary AI (PAI), 24 patients with secondary AI (SAI) and 31 patients with adrenal insufficiency after treatment for Cushing's syndrome (Cush-AI). Measurements included computerised questionnaires to determine fatigue severity and physical and psychosocial contributors. Patients took four saliva samples at home, in which cortisol levels were measured.

RESULTS

Severe fatigue was experienced by 41 % of the CAH patients, 42 % of the PAI patients, 50 % of the SAI patients and 42 % of the Cush-AI patients. Psychological distress, functional impairment, sleep disturbance, physical activity, concentration problems and social functioning contributed to the subjective experience of fatigue. Salivary cortisol levels were not correlated with momentary fatigue.

CONCLUSIONS

A considerable proportion of AI patients experience severe fatigue. Salivary cortisol level is not a significant predictor for momentary fatigue in AI patients.

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.

Exercise affects symptom severity but not biological measures in depression and somatization - results on IL-6, neopterin, tryptophan, kynurenine and 5-HIAA

Exercise leads to symptom reduction in affective disorders and functional somatic syndromes. Biological hypotheses of underlying mechanisms include serotonergic and immunological pathways. We aimed to investigate biological features in persons with major depression and somatoform syndromes, and to analyze effects of short-term graded exercise on these parameters. Baseline values for depressive and somatoform symptoms, tryptophan, kynurenine, 5-hydroxyindoleacetic acid, neopterin and interleukin-6 were compared with those after one week of increased and one week of reduced physical activity. Thirty-eight persons with major depression, 27 persons with a minimum of 6-8 somatoform symptoms, and 48 healthy controls participated in the study. Depressive and somatoform symptoms were reduced after the active week, and an interaction pointed towards group-specific reduction of psychopathology. Participants with major depression had lower levels of kynurenine compared to controls, with intermediate concentrations in somatoform patients. There were no systematic associations of symptom improvement with biological changes. A possible limitation of the design is that a control condition with low physical activity, but no placebo condition was included. People with multiple somatoform symptoms and major depression benefit from a short and low-graded exercise intervention. These effects do not seem to be mediated by changes in serotonergic and inflammatory parameters.

The effects of exercise on dynamic sleep morphology in healthy controls and patients with chronic fatigue syndrome

Effects of exercise on dynamic aspects of sleep have not been studied. We hypothesized exercise altered dynamic sleep morphology differently for healthy controls relative to chronic fatigue syndrome (CFS) patients. Sixteen controls (38 ± 9 years) and 17 CFS patients (41 ± 8 years) underwent polysomnography on baseline nights and nights after maximal exercise testing. We calculated transition probabilities and rates (as a measure of relative and temporal transition frequency, respectively) between sleep stages and cumulative duration distributions (as a measure of continuity) of each sleep stage and sleep as a whole. After exercise, controls showed a significantly greater probability of transition from N1 to N2 and a lower rate of transition from N1 to wake than at baseline; CFS showed a significantly greater probability of transition from N2 to N3 and a lower rate of transition from N2 to N1. These findings suggest improved quality of sleep after exercise. After exercise, controls had improved sleep continuity, whereas CFS had less continuous N1 and more continuous rapid eye movement (REM) sleep. However, CFS had a significantly greater probability and rate of transition from REM to wake than controls. Probability of transition from REM to wake correlated significantly with increases in subjective fatigue, pain, and sleepiness overnight in CFS - suggesting these transitions may relate to patient complaints of unrefreshing sleep. Thus, exercise promoted transitions to deeper sleep stages and inhibited transitions to lighter sleep stages for controls and CFS, but CFS also reported increased fatigue and continued to have REM sleep disruption. This dissociation suggests possible mechanistic pathways for the underlying pathology of CFS.

Chronic fatigue and personality: a twin study of causal pathways and shared liabilities

BACKGROUND

The etiology of chronic fatigue syndrome (CFS) remains unknown. Personality traits influence well-being and may play a role in CFS and unexplained chronic fatigue.

PURPOSE

This study aimed to examine the association of emotional instability and extraversion with chronic fatigue and CFS in a genetically informative sample.

METHODS

We evaluated 245 twin pairs for two definitions of chronic fatigue. They completed the Neuroticism and Extraversion subscales of the NEO Five Factor Inventory. Using a co-twin control design, we examined the association between personality and chronic fatigue.

RESULTS

Higher emotional instability was associated with both definitions of chronic fatigue and was confounded by shared genetics. Lower extraversion was also associated with both definitions of fatigue, but was not confounded by familial factors.

CONCLUSIONS

Both emotional instability and extraversion are related to chronic fatigue and CFS. Whereas emotional instability and chronic fatigue are linked by shared genetic mechanisms, the relationship with extraversion may be causal and bidirectional.

Recovery from chronic fatigue syndrome after treatments given in the PACE trial

BACKGROUND

A multi-centre, four-arm trial (the PACE trial) found that rehabilitative cognitive behaviour therapy (CBT) and graded exercise therapy (GET) were more effective treatments for chronic fatigue syndrome (CFS) than specialist medical care (SMC) alone, when each was added to SMC, and more effective than adaptive pacing therapy (APT) when added to SMC. In this study we compared how many participants recovered after each treatment.

METHOD

We defined recovery operationally using multiple criteria, and compared the proportions of participants meeting each individual criterion along with two composite criteria, defined as (a) recovery in the context of the trial and (b) clinical recovery from the current episode of the illness, however defined, 52 weeks after randomization. We used logistic regression modelling to compare treatments.

RESULTS

The percentages (number/total) meeting trial criteria for recovery were 22% (32/143) after CBT, 22% (32/143) after GET, 8% (12/149) after APT and 7% (11/150) after SMC. Similar proportions met criteria for clinical recovery. The odds ratio (OR) for trial recovery after CBT was 3.36 [95% confidence interval (CI) 1.64–6.88] and for GET 3.38 (95% CI 1.65–6.93), when compared to APT, and after CBT 3.69 (95% CI 1.77–7.69) and GET 3.71 (95% CI 1.78–7.74), when compared to SMC (p values < or =0.001 for all comparisons). There was no significant difference between APT and SMC. Similar proportions recovered in trial subgroups meeting different definitions of the illness.

CONCLUSIONS

This study confirms that recovery from CFS is possible, and that CBT and GET are the therapies most likely to lead to recovery.

The protocol for a randomised controlled trial comparing intermittent and graded exercise to usual care for chronic fatigue syndrome patients

Background

Chronic Fatigue Syndrome is a debilitating disorder with an unknown aetiology but suspected multifactorial origins. Common “triggers” include severe viral infections and emotional stress. Recent studies have also found evidence of immune dysfunction and elevated inflammatory cytokines in CFS patients, but there has been considerable variation in the outcome measures and magnitude of these studies. Currently, there is no cure for CFS but treatments include rest, specialist medical care, cognitive behavioural therapy, and graded (self-paced) exercise. To date, several studies have examined the efficacy of graded exercise with or without Cognitive Behavioural Therapy, with some success for patients. However, improvements in functional capacity have not necessarily correlated with improvements in immune function, fatigue or other symptoms. This 12-week pilot trial compares graded and intermittent exercise to normal care, measuring physiological outcomes, fatigue levels, immune function and wellness.

Methods/design

90 patients aged between 16 to 60 years, who meet the diagnostic criteria for CFS and have been diagnosed by their medical practitioner, will be randomly recruited into groups consisting of Intermittent exercise, Graded exercise and usual care (Control). The outcomes will be measured pre-study (Week 0) and post-study (Week 13). Primary outcomes are VO_2peak, anaerobic threshold, peak power, levels of fatigue, immune cell (CD3⁺CD4⁺, CD3⁺CD8⁺, CD19⁺, CD 16⁺CD56⁺) concentrations and activation. Secondary outcomes include onset of secondary CFS symptoms (e.g. fever, swollen lymph nodes), wellness, mood and sleep patterns. Primary analysis will be based on intention to treat using logistic regression models to compare treatments. Quantitative data will be analysed using repeated measures ANOVA with a linear model, and Cohen’s effect size. Qualitative data such as participants’ responses (e.g. changes in mood and other reactions) following the exercise modalities will be read and sections demarcated. A code will be applied to each segment. A prevalence of codes will be considered thematically.

Discussion

The results of the trial will provide information about the efficacy of intermittent and graded exercise compared to usual care (rest and lifestyle recommendations), contributing to the evidence for best-practice CFS management.

Trial registration

Australia and New Zealand Clinical Trials Registry ACTRN12612001241820.

Caught in the thickness of brain fog: exploring the cognitive symptoms of Chronic Fatigue Syndrome

Chronic Fatigue Syndrome (CFS) is defined as greater than 6 months of persistent fatigue that is experienced physically and cognitively. The cognitive symptoms are generally thought to be a mild cognitive impairment, but individuals with CFS subjectively describe them as "brain fog." The impairment is not fully understood and often is described as slow thinking, difficulty focusing, confusion, lack of concentration, forgetfulness, or a haziness in thought processes. Causes of "brain fog" and mild cognitive impairment have been investigated. Possible physiological correlates may be due to the effects of chronic orthostatic intolerance (OI) in the form of the Postural Tachycardia Syndrome (POTS) and decreases in cerebral blood flow (CBF). In addition, fMRI studies suggest that individuals with CFS may require increased cortical and subcortical brain activation to complete difficult mental tasks. Furthermore, neurocognitive testing in CFS has demonstrated deficits in speed and efficiency of information processing, attention, concentration, and working memory. The cognitive impairments are then perceived as an exaggerated mental fatigue. As a whole, this is experienced by those with CFS as "brain fog" and may be viewed as the interaction of physiological, cognitive, and perceptual factors. Thus, the cognitive symptoms of CFS may be due to altered CBF activation and regulation that are exacerbated by a stressor, such as orthostasis or a difficult mental task, resulting in the decreased ability to readily process information, which is then perceived as fatiguing and experienced as "brain fog." Future research looks to further explore these interactions, how they produce cognitive impairments, and explain the perception of "brain fog" from a mechanistic standpoint.