Deconstructing post-exertional malaise: An exploratory factor analysis

Abstract:

Post-exertional malaise is a cardinal symptom of myalgic encephalomyelitis and chronic fatigue syndrome. There are two differing focuses when defining post-exertional malaise: a generalized, full-body fatigue and a muscle-specific fatigue. This study aimed to discern whether post-exertional malaise is a unified construct or whether it is composed of two smaller constructs, muscle fatigue and generalized fatigue. An exploratory factor analysis was conducted on several symptoms that assess post-exertional malaise. The results suggest that post-exertional malaise is composed of two empirically different experiences, one for generalized fatigue and one for muscle-specific fatigue.

© The Author(s) 2016.

 

Source: McManimen SL, Sunnquist ML, Jason LA. Deconstructing post-exertional malaise: An exploratory factor analysis. J Health Psychol. 2016 Aug 24. pii: 1359105316664139. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/27557649

 

Do evidence based interventions for chronic fatigue syndrome improve sleep? A systematic review and narrative synthesis

Abstract:

Cognitive behavioural therapy (CBT) and graded exercise therapy (GET) are recommended evidence based treatments for chronic fatigue syndrome (CFS), with research supporting their effectiveness in reducing fatigue and functional impairment. However, little research has focussed on the effect of these treatments on sleep, despite high reported sleep disturbance in CFS.

Using a narrative synthesis approach, we aimed to 1) systematically identify and summarise the current evidence for the effectiveness of CBT and GET in improving sleep; 2) consider factors influencing treatment effectiveness, including incorporation of sleep management techniques; and 3) consider the appropriateness of sleep outcome measures used within evaluations. Studies evaluating CBT and/or GET for CFS, and including a sleep outcome were eligible for inclusion. Eight studies were identified.

We found that GET interventions can improve sleep but this effect is inconsistent across studies. For CBT the evidence is limited with only one of two evaluations demonstrating sleep-related improvements.

We conclude from existing research that we know little about the effects of including sleep management components within CBT and GET interventions. We suggest that future research should explore the effectiveness of sleep components within interventions, and sleep specific interventions, using comprehensive outcome measures that fully capture the range of sleep difficulties experienced in CFS.

Copyright © 2016 Elsevier Ltd. All rights reserved.

 

Source: Russell C, Kyle SD, Wearden AJ. Do evidence based interventions for chronic fatigue syndrome improve sleep? A systematic review and narrative synthesis. Sleep Med Rev. 2016 May 13. pii: S1087-0792(16)30012-0. doi: 10.1016/j.smrv.2016.05.001. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/27524207

 

TauG-guidance of dynamic balance control during gait initiation in patients with chronic fatigue syndrome and fibromyalgia

Abstract:

BACKGROUND: Impaired postural control has been reported in static conditions in chronic fatigue syndrome and fibromyalgia, but postural control in dynamic tasks have not yet been investigated. Thus, we investigated measurements from a force plate to evaluate dynamic balance control during gait initiation in patients with chronic fatigue syndrome and fibromyalgia compared to matched healthy controls.

METHODS: Thirty female participants (10 per group) performed five trials of gait initiation. Center of pressure (CoP) trajectory of the initial weight shift onto the supporting foot in the mediolateral direction (CoPX) was analyzed using General Tau Theory. We investigated the hypothesis that tau of the CoPX motion-gap (τCoPx) is coupled onto an intrinsic tauG-guide (τG) by keeping the relation τCoPx=KτG, where K is a scaling factor that determines the relevant kinematics of a movement.

FINDINGS: Mean K values were 0.57, 0.55, and 0.50 in fibromyalgia, chronic fatigue syndrome, and healthy controls, respectively. Both patient groups showed K values significantly higher than 0.50 (P<0.05), indicating that patients showed poorer dynamic balance control, CoPX colliding with the boundaries of the base of support (K>0.5).

INTERPRETATION: The findings revealed a lower level of dynamic postural control in both fibromyalgia and chronic fatigue syndrome compared to controls.

Copyright © 2016 Elsevier Ltd. All rights reserved.

 

Source: Rasouli O, Stensdotter AK, Van der Meer AL. TauG-guidance of dynamic balance control during gait initiation in patients with chronic fatigue syndrome and fibromyalgia. Clin Biomech (Bristol, Avon). 2016 Aug;37:147-52. doi: 10.1016/j.clinbiomech.2016.07.008. Epub 2016 Jul 22. https://www.ncbi.nlm.nih.gov/pubmed/27474799

 

Neuromuscular Strain Increases Symptom Intensity in Chronic Fatigue Syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a complex, multisystem disorder that can be disabling. CFS symptoms can be provoked by increased physical or cognitive activity, and by orthostatic stress. In preliminary work, we noted that CFS symptoms also could be provoked by application of longitudinal neural and soft tissue strain to the limbs and spine of affected individuals.

In this study we measured the responses to a straight leg raise neuromuscular strain maneuver in individuals with CFS and healthy controls. We randomly assigned 60 individuals with CFS and 20 healthy controls to either a 15 minute period of passive supine straight leg raise (true neuromuscular strain) or a sham straight leg raise. The primary outcome measure was the symptom intensity difference between the scores during and 24 hours after the study maneuver compared to baseline.

Fatigue, body pain, lightheadedness, concentration difficulties, and headache scores were measured individually on a 0-10 scale, and summed to create a composite symptom score. Compared to individuals with CFS in the sham strain group, those with CFS in the true strain group reported significantly increased body pain (P = 0.04) and concentration difficulties (P = 0.02) as well as increased composite symptom scores (all P = 0.03) during the maneuver.

After 24 hours, the symptom intensity differences were significantly greater for the CFS true strain group for the individual symptom of lightheadedness (P = 0.001) and for the composite symptom score (P = 0.005). During and 24 hours after the exposure to the true strain maneuver, those with CFS had significantly higher individual and composite symptom intensity changes compared to the healthy controls.

We conclude that a longitudinal strain applied to the nerves and soft tissues of the lower limb is capable of increasing symptom intensity in individuals with CFS for up to 24 hours. These findings support our preliminary observations that increased mechanical sensitivity may be a contributor to the provocation of symptoms in this disorder.

 

Source: Rowe PC, Fontaine KR, Lauver M, Jasion SE, Marden CL, Moni M, Thompson CB, Violand RL. Neuromuscular Strain Increases Symptom Intensity in Chronic Fatigue Syndrome. PLoS One. 2016 Jul 18;11(7):e0159386. doi: 10.1371/journal.pone.0159386. ECollection 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4948885/ (Full article)

 

Factor Analysis of the DePaul Symptom Questionnaire: Identifying Core Domains

Abstract:

The present study attempted to identify critical symptom domains of individuals with Myalgic Encephalomyelitis (ME) and chronic fatigue syndrome (CFS). Using patient and control samples collected in the United States, Great Britain, and Norway, exploratory factor analysis (EFA) was used to establish the underlying factor structure of ME and CFS symptoms.

The EFA suggested a four-factor solution: post-exertional malaise, cognitive dysfunction, sleep difficulties, and a combined factor consisting of neuroendocrine, autonomic, and immune dysfunction symptoms. The use of empirical methods could help better understand the fundamental symptom domains of this illness.

 

Source: Jason LA, Sunnquist M, Brown A, Furst J, Cid M, Farietta J, Kot B, Bloomer C, Nicholson L, Williams Y, Jantke R, Newton JL, Strand EB. Factor Analysis of the DePaul Symptom Questionnaire: Identifying Core Domains. J Neurol Neurobiol. 2015 Sep;1(4). doi: 10.16966/2379-7150.114. Epub 2015 Sep 17. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4830389/ (Full article)

 

Chronic fatigue syndrome and sleep disorders: clinical associations and diagnostic difficulties.

Abstract:

INTRODUCTION: Chronic fatigue syndrome (CFS) is characterised by the presence of intractable fatigue and non-restorative sleep, symptoms which are also very prevalent in multiple diseases and appear as side effects of different drugs. Numerous studies have shown a high prevalence of sleep disorders in patients with CFS. However, non-restorative sleep and fatigue are frequently symptoms of the sleep disorders themselves, so primary sleep disorders have to be ruled out in many cases of CFS.

DEVELOPMENT: This review was performed using a structured search of the MeSH terms ([Sleep]+[Chronic fatigue syndrome]) in the PubMed database.

CONCLUSION: Identifying primary sleep disorders in patients meeting diagnostic criteria for CFS will allow for a more comprehensive treatment approach involving new diagnostic and therapeutic strategies that may improve quality of life for these patients.

Copyright © 2016 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

 

Source: Ferré A. Chronic fatigue syndrome and sleep disorders: clinical associations and diagnostic difficulties. Neurologia. 2016 Feb 11. pii: S0213-4853(16)00010-4. doi: 10.1016/j.nrl.2015.11.019. [Epub ahead of print] [Article in English, Spanish] https://www.ncbi.nlm.nih.gov/pubmed/26877195 (Full text available as PDF)

 

The aetiopathogenesis of fatigue: unpredictable, complex and persistent

Abstract:

BACKGROUND: Chronic fatigue syndrome is a common condition characterized by severe fatigue with post-exertional malaise, impaired cognitive ability, poor sleep quality, muscle pain, multi-joint pain, tender lymph nodes, sore throat or headache. Its defining symptom, fatigue is common to several diseases.

AREAS OF AGREEMENT: Research has established a broad picture of impairment across autonomic, endocrine and inflammatory systems though progress seems to have reached an impasse.

AREAS OF CONTROVERSY: The absence of a clear consensus view of the pathophysiology of fatigue suggests the need to switch from a focus on abnormalities in one system to an experimental and clinical approach which integrates findings across multiple systems and their constituent parts and to consider multiple environmental factors.

GROWING POINTS: We discuss this with reference to three key factors, non-determinism, non-reductionism and self-organization and suggest that an approach based on these principles may afford a coherent explanatory framework for much of the observed phenomena in fatigue and offers promising avenues for future research.

AREAS TIMELY FOR DEVELOPING RESEARCH: By adopting this approach, the field can examine issues regarding aetiopathogenesis and treatment, with relevance for future research and clinical practice.

© The Author 2016. Published by Oxford University Press.

 

Source: Clark JE, Fai Ng W, Watson S, Newton JL. The aetiopathogenesis of fatigue: unpredictable, complex and persistent. Br Med Bull. 2016 Mar;117(1):139-48. doi: 10.1093/bmb/ldv057. Epub 2016 Feb 12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4782751/ (Full article)

 

Chronic fatigue syndrome (CFS) symptom-based phenotypes in two clinical cohorts of adult patients in the UK and The Netherlands

Abstract:

OBJECTIVE: Studies have provided evidence of heterogeneity within chronic fatigue syndrome (CFS), but few have used data from large cohorts of CFS patients or replication samples.

METHODS: 29 UK secondary-care CFS services recorded the presence/absence of 12 CFS-related symptoms; 8 of these symptoms were recorded by a Dutch tertiary service. Latent Class Analysis (LCA) was used to assign symptom profiles (phenotypes). Regression models were fitted with phenotype as outcome (in relation to age, sex, BMI, duration of illness) and exposure (in relation to comorbidities and patient-reported measures).

RESULTS: Data were available for 7041 UK and 1392 Dutch patients. Almost all patients in both cohorts presented with post-exertional malaise, cognitive dysfunction and disturbed/unrefreshing sleep, and these 3 symptoms were excluded from LCA. In UK patients, six phenotypes emerged: ‘full’ polysymptomatic (median 8, IQR 7-9 symptoms) 32.8%; ‘pain-only’ (muscle/joint) 20.3%; ‘sore throat/painful lymph node’ 4.5%; and ‘oligosymptomatic’ (median 1, IQR 0-2 symptoms) 4.7%. Two ‘partial’ polysymptomatic phenotypes were similar to the ‘full’ phenotype, bar absence of dizziness/nausea/palpitations (21.4%) or sore throat/painful lymph nodes (16.3%). Women and patients with longer duration of illness were more likely to be polysymptomatic. Polysymptomatic patients had more severe illness and more comorbidities. LCA restricted to 5 symptoms recorded in both cohorts indicated 3 classes (polysymptomatic, oligosymptomatic, pain-only), which were replicated in Dutch data.

CONCLUSIONS: Adults with CFS may have one of 6 symptom-based phenotypes associated with sex, duration and severity of illness, and comorbidity. Future research needs to determine whether phenotypes predict treatment outcomes, and require different treatments.

Copyright © 2015 Elsevier Inc. All rights reserved.

 

Source: Collin SM, Nikolaus S, Heron J, Knoop H, White PD, Crawley E. Chronic fatigue syndrome (CFS) symptom-based phenotypes in two clinical cohorts of adult patients in the UK and The Netherlands. J Psychosom Res. 2016 Feb;81:14-23. doi: 10.1016/j.jpsychores.2015.12.006. Epub 2015 Dec 23. https://www.ncbi.nlm.nih.gov/pubmed/26800634

 

Mitochondrial DNA variants correlate with symptoms in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

BACKGROUND: Mitochondrial dysfunction has been hypothesized to occur in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), a disease characterized by fatigue, cognitive difficulties, pain, malaise, and exercise intolerance. We investigated whether haplogroup, single nucleotide polymorphisms (SNPs), or heteroplasmy of mitochondrial DNA (mtDNA) were associated with health status and/or symptoms.

METHODS: Illumina sequencing of PCR-amplified mtDNA was performed to analyze sequence and extent of heteroplasmy of mtDNAs of 193 cases and 196 age- and gender-matched controls from DNA samples collected by the Chronic Fatigue Initiative. Association testing was carried out to examine possible correlations of mitochondrial sequences with case/control status and symptom constellation and severity as reported by subjects on Short Form-36 and DePaul Symptom Questionnaires.

RESULTS: No ME/CFS subject exhibited known disease-causing mtDNA mutations. Extent of heteroplasmy was low in all subjects. Although no association between mtDNA SNPs and ME/CFS vs. healthy status was observed, haplogroups J, U and H as well as eight SNPs in ME/CFS cases were significantly associated with individual symptoms, symptom clusters, or symptom severity.

CONCLUSIONS: Analysis of mitochondrial genomes in ME/CFS cases indicates that individuals of a certain haplogroup or carrying specific SNPs are more likely to exhibit certain neurological, inflammatory, and/or gastrointestinal symptoms. No increase in susceptibility to ME/CFS of individuals carrying particular mitochondrial genomes or SNPs was observed.

 

Source: Billing-Ross P, Germain A, Ye K, Keinan A, Gu Z, Hanson MR. Mitochondrial DNA variants correlate with symptoms in myalgic encephalomyelitis/chronic fatigue syndrome. J Transl Med. 2016 Jan 20;14:19. doi: 10.1186/s12967-016-0771-6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4719218/ (Full article)

 

Sleep quality and the treatment of intestinal microbiota imbalance in Chronic Fatigue Syndrome: A pilot study

Abstract:

Chronic Fatigue Syndrome (CFS) is a multisystem illness, which may be associated with imbalances in gut microbiota. This study builds on recent evidence that sleep may be influenced by gut microbiota, by assessing whether changes to microbiota in a clinical population known to have both poor sleep and high rates of colonization with gram-positive faecal Streptococcus, can improve sleep.

Twenty-one CFS participants completed a 22- day open label trial. Faecal microbiota analysis was performed at baseline and at the end of the trial. Participants were administered erythromycin 400 mg b.d. for 6 days. Actigraphy and questionnaires were used to monitor sleep, symptoms and mood. Changes in patients who showed a clinically significant change in faecal Streptococcus after treatment (responders; defined as post-therapy distribution<6%) were compared to participants who did not respond to treatment.

In the seven responders, there was a significant increase in actigraphic total sleep time (p=0.028) from baseline to follow up, compared with non-responders. Improved vigour scores were associated with a lower Streptococcus count (ρ=-0.90, p=0.037). For both the responders and the whole group, poorer mood was associated with higher Lactobacillus.

Short term antibiotic treatment appears to be insufficient to effect sustainable changes in the gut ecosystem in most CFS participants. Some improvement in objective sleep parameters and mood were found in participants with reduced levels of gram-positive gut microbiota after antibiotic treatment, which is encouraging. Further study of possible links between gut microorganisms and sleep and mood disturbances is warranted.

 

Source: Jackson ML, Butt H, Ball M, Lewis DP, Bruck D. Sleep quality and the treatment of intestinal microbiota imbalance in Chronic Fatigue Syndrome: A pilot study. Sleep Sci. 2015 Nov;8(3):124-33. doi: 10.1016/j.slsci.2015.10.001. Epub 2015 Oct 23. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4688574/ (Full article)