On the Prevalence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome after a SARS-CoV-2 infection

Introduction:

There is an increasing body of evidence connecting the post-acute SARS-CoV-2 condition (PASC, commonly known as long COVID) to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), a debilitating disease of unknown cause characterized by persistent and unexplained fatigue, post-exertional malaise (PEM), among other symptoms. This connection implies that, in the clinic, some PASC cases comply with the official case definitions of ME/CFS. As such, there is a necessity to quantify the burden of ME/CFS among the PASC population in order to delineate effective healthcare interventions for the benefit of these patients who are often neglected or, in some extreme cases, stigmatized by medical staff and society.
To answer this urgent research question, Dehlia and Guthridge performed a systematic review and meta-analysis of recent data on PASC adults and reported an ME/CFS prevalence estimate of 51% (95% CI, 42%-60%); this systematic review and meta-analysis will be referred to as PASC-ME/CFS study. In the present Letter to Editor, we aimed to discuss the reliability of this estimate using the research protocol from the European Network on ME/CFS (EUROMENE) for systematic reviews and meta-analysis on the epidemiology burden of ME/CFS in Europe.

Source: Sepúlveda N, Westermeier F. On the Prevalence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome after a SARS-CoV-2 infection. J Infect. 2024 Nov 16:106353. doi: 10.1016/j.jinf.2024.106353. Epub ahead of print. PMID: 39557089. Sepúlveda N, Westermeier F. On the Prevalence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome after a SARS-CoV-2 infection. J Infect. 2024 Nov 16:106353. doi: 10.1016/j.jinf.2024.106353. Epub ahead of print. PMID: 39557089. https://www.journalofinfection.com/article/S0163-4453(24)00288-3/fulltext (Full text)

Qigong and Tai Chi for ME/CFS: A Systematic Review of Randomized Controlled Trials

Abstract:

Objective: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic and debilitating illness with symptoms such as post-exertional malaise and cognitive dysfunction that can be challenging for patients to manage independently. Randomized controlled trials (RCTs) have examined mind-body and psychological approaches that teach patients coping skills for mitigating ME/CFS symptoms, including emerging literature on Qigong or Tai Chi instruction programs. This systematic review aims to summarize the characteristics of these trials and highlight potential areas for future optimization and refinement.

Methods: Ovid MEDLINE, Embase.com, Web of Science Core Collection, Cochrane CENTRAL, PsycINFO via Ovid, and ClinicalTrials.gov were searched in April 2023 using controlled vocabulary and keywords for the following eligibility criteria: Sample (ME/CFS), Design (RCT), Behavioral Intervention (mind-body or psychological interventions). Data extraction and reporting followed Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results: “Qigong” and “Tai Chi” yielded 142 and 80 abstracts, respectively. Of the 222 abstracts, full texts were available for 5 RCTs of Qigong (k = 5; N = 481). Notably, no trials of Tai Chi utilized a randomized control design. Among the 5 Qigong RCTs, the publication range was from 2012 to 2023. Details regarding intervention components and effects were summarized. Qigong intervention sessions (median = 12, mode = 10, 12) tended to last between 1-2 hours and occur across 5-12 weeks (median = 7, mode = 5). The Qigong interventions were all delivered in groups and incorporated at-home practice. Daily practice was a requirement (k = 4) or an advisement (k = 1). Patient-reported outcomes suggest an emerging evidence base for diffuse benefits on physical and emotional health outcomes.

Conclusions: Qigong interventions are promising, yet relatively understudied, in improving ME/CFS symptom severity and frequency. Future trials must implement standardized eligibility criteria for ME/CFS history, integrate Qigong or Tai Chi with other empirically supported mind-body and psychological practices, and assess long-term resiliency outcomes relevant to ME/CFS survivorship.

Source: Markwart M, Felsenstein D, Mehta DH, Sethi S, Tsuchiyose E, Lydson M, Yeh GY, Hall DL. Qigong and Tai Chi for ME/CFS: A Systematic Review of Randomized Controlled Trials. Glob Adv Integr Med Health. 2024 Nov 7;13:27536130241275607. doi: 10.1177/27536130241275607. PMID: 39524182; PMCID: PMC11544658. https://pmc.ncbi.nlm.nih.gov/articles/PMC11544658/ (Full text)

Adrenergic dysfunction in patients with myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia: A systematic review and meta-analysis

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia (FM) are comorbid disorders with overlapping symptoms. Research highlights autonomic dysfunction compared to healthy individuals, particularly involving the sympathetic branch. While past reviews focused on neurophysiological assessments, this systematic review summarises biological adrenergic markers, offering deeper insights into the observed sympathetic dysfunction in ME/CFS and FM aiming to identify targetable pathophysiological mechanisms.

Methods: A systematic search was performed on PubMed, Web of Science, Embase and Scopus. Studies investigating peripheral biological markers of adrenergic function in patients with ME/CFS or FM compared to healthy controls at baseline were included. Meta-analyses were performed using R statistical software.

Results: This meta-analysis of 37 studies, encompassing 543 ME/CFS patients and 651 FM patients, compared with 747 and 447 healthy controls, respectively, revealed elevated adrenaline (SMD = .49 [.31-.67]; Z = 5.29, p < .01) and β1 adrenergic receptor expression (SMD = .79 [.06-1.52]; Z = 2.13; p = .03) in blood of ME/CFS patients at rest. Additionally, patients with ME/CFS had a greater increase in the expression of α2A adrenergic receptor (AR, SMD = .57 [.18-.97]; Z = 2.85, p < .01), β2 AR (SMD = .41 [.02-.81]; Z = 2.04; p = .04) and COMT (SMD = .42 [.03-.81]; Z = 2.11; p = .03) after exercise and an increased response of noradrenaline to an orthostatic test (SMD = .11 [-.47 to -.70]; Z = 2.10; p = .04), both found in blood. FM patients showed no significant differences at baseline but exhibited a diminished adrenaline response to exercise (SMD = -.79 [-1.27 to -.30]; Z = -3.14; p < .01).

Conclusion: This systematic review and meta-analysis revealed adrenergic dysfunction mainly in patients with ME/CFS. Higher baseline adrenaline levels and atypical responses to exercise in ME/CFS indicate that sympathetic dysfunction, underscored by adrenergic abnormalities, is more involved in the pathophysiology of ME/CFS rather than FM.

Source: Hendrix J, Fanning L, Wyns A, Ahmed I, Patil MS, Richter E, Van Campenhout J, Ickmans K, Mertens R, Nijs J, Godderis L, Polli A. Adrenergic dysfunction in patients with myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia: A systematic review and meta-analysis. Eur J Clin Invest. 2024 Sep 25:e14318. doi: 10.1111/eci.14318. Epub ahead of print. PMID: 39319943. https://pubmed.ncbi.nlm.nih.gov/39319943/

Systematic review of fatigue severity in ME/CFS patients: insights from randomized controlled trials

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating illness medically unexplained, affecting approximately 1% of the global population. Due to the subjective complaint, assessing the exact severity of fatigue is a clinical challenge, thus, this study aimed to produce comprehensive features of fatigue severity in ME/CFS patients.

Methods: We systematically extracted the data for fatigue levels of participants in randomized controlled trials (RCTs) targeting ME/CFS from PubMed, Cochrane Library, Web of Science, and CINAHL throughout January 31, 2024. We normalized each different measurement to a maximum 100-point scale and performed a meta-analysis to assess fatigue severity by subgroups of age, fatigue domain, intervention, case definition, and assessment tool, respectively.

Results: Among the total of 497 relevant studies, 60 RCTs finally met our eligibility criteria, which included a total of 7088 ME/CFS patients (males 1815, females 4532, and no information 741). The fatigue severity of the whole 7,088 patients was 77.9 (95% CI 74.7-81.0), showing 77.7 (95% CI 74.3-81.0) from 54 RCTs in 6,706 adults and 79.6 (95% CI 69.8-89.3) from 6 RCTs in 382 adolescents. Regarding the domain of fatigue, ‘cognitive’ (74.2, 95% CI 65.4-83.0) and ‘physical’ fatigue (74.3, 95% CI 68.3-80.3) were a little higher than ‘mental’ fatigue (70.1, 95% CI 64.4-75.8). The ME/CFS participants for non-pharmacological intervention (79.1, 95% CI 75.2-83.0) showed a higher fatigue level than those for pharmacological intervention (75.5, 95% CI 70.0-81.0). The fatigue levels of ME/CFS patients varied according to diagnostic criteria and assessment tools adapted in RCTs, likely from 54.2 by ICC (International Consensus Criteria) to 83.6 by Canadian criteria and 54.2 by MFS (Mental Fatigue Scale) to 88.6 by CIS (Checklist Individual Strength), respectively.

Conclusions: This systematic review firstly produced comprehensive features of fatigue severity in patients with ME/CFS. Our data will provide insights for clinicians in diagnosis, therapeutic assessment, and patient management, as well as for researchers in fatigue-related investigations.

Source: Park JW, Park BJ, Lee JS, Lee EJ, Ahn YC, Son CG. Systematic review of fatigue severity in ME/CFS patients: insights from randomized controlled trials. J Transl Med. 2024 Jun 3;22(1):529. doi: 10.1186/s12967-024-05349-7. PMID: 38831460; PMCID: PMC11145935. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11145935/ (Full text)

Nutrition and Chronobiology as Key Components of Multidisciplinary Therapeutic Interventions for Fibromyalgia and Associated Chronic Fatigue Syndrome: A Narrative and Critical Review

Abstract:

Fibromyalgia (FM) is often accompanied by chronic fatigue syndrome (CFS). It is a poorly understood disorder that mainly affects women and leads to chronic pain, fatigue, and insomnia, among other symptoms, which decrease quality of life. Due to the inefficiency of current pharmacological treatments, increasing interest is being directed towards non-pharmacological multicomponent therapies. However, nutrition and chronobiology are often overlooked when developing multicomponent therapies.

This narrative and critical review explore the relevance of nutritional and chronobiological strategies in the therapeutic management of FM and the often-associated CFS. Reviewed literature offers scientific evidence for the association of dietary habits, nutrient levels, body composition, gut microbiota imbalance, chronobiological alterations, and their interrelation with the development and severity of symptoms. This review highlights the key role of nutrition and chronobiology as relevant and indispensable components in a multidisciplinary approach to FM and CFS.

Source: Carrasco-Querol N, Cabricano-Canga L, Bueno Hernández N, Gonçalves AQ, Caballol Angelats R, Pozo Ariza M, Martín-Borràs C, Montesó-Curto P, Castro Blanco E, Dalmau Llorca MR, et al. Nutrition and Chronobiology as Key Components of Multidisciplinary Therapeutic Interventions for Fibromyalgia and Associated Chronic Fatigue Syndrome: A Narrative and Critical Review. Nutrients. 2024; 16(2):182. https://doi.org/10.3390/nu16020182 https://www.mdpi.com/2072-6643/16/2/182 (Full text)

Effectiveness of Antiviral Therapy on Long COVID: A Systematic Review and Meta-Analysis

Abstract:

Antiviral treatment reduces the severity and mortality of SARS-CoV-2 infection; however, its effectiveness against long COVID-19 is unclear. This study aimed to evaluate the effectiveness of antiviral drugs in preventing long COVID and related hospitalizations/deaths. Scientific and medical databases were searched from 1 January 2020 to 30 June 2023. We included observational cohort studies comparing individuals receiving early antiviral therapy for COVID-19 and those receiving supportive treatment.
A fixed-effects model was used to merge the effects reported in two or more studies. The risk of post-acute sequelae of COVID-19 (PASC) was combined as an odds ratio (OR). Six studies were selected, including a total of 3,352,235 participants. The occurrence of PASC was 27.5% lower in patients who received antiviral drugs during the early stages of SARS-CoV-2 infection (OR = 0.725; 95% confidence interval [CI] = 0.409–0.747) than in the supportive treatment group. Moreover, the risk of PASC-associated hospitalization and mortality was 29.7% lower in patients receiving early antiviral therapy than in the supportive treatment group (OR = 0.721; 95% CI = 0.697–0.794).
Early antiviral therapy was associated with a reduced risk of PASC and related hospitalization or death. Thus, early antiviral therapy is recommended for at-risk individuals.
Source: Choi YJ, Seo YB, Seo J-W, Lee J, Nham E, Seong H, Yoon JG, Noh JY, Cheong HJ, Kim WJ, et al. Effectiveness of Antiviral Therapy on Long COVID: A Systematic Review and Meta-Analysis. Journal of Clinical Medicine. 2023; 12(23):7375. https://doi.org/10.3390/jcm12237375 https://www.mdpi.com/2077-0383/12/23/7375 (Full text)

Effects of traditional Chinese mind-body exercises for patients with chronic fatigue syndrome: A systematic review and meta-analysis

Abstract:

Background: Chronic fatigue syndrome (CFS) is a global public health concern. We performed this systematic review of randomised controlled trials (RCTs) to evaluate the effects and safety of traditional Chinese mind-body exercises (TCME) for patients with CFS.

Methods: We comprehensively searched MEDLINE, Embase, Web of Science, PsycINFO, Cochrane Library, CNKI, VIP databases, and Wanfang Data from inception to October 2022 for eligible RCTs of TCME for CFS management. We used Cochran’s Q statistic and I2 to assess heterogeneity and conducted subgroup analyses based on different types of TCME, background therapy, and types of fatigue. We also assessed the quality of evidence using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach.

Results: We included 13 studies (n = 1187) with a maximal follow-up of 12 weeks. TCME included Qigong and Tai Chi. At the end of the treatment, compared with passive control, TCME probably reduces the severity of fatigue (standardised mean differences (SMD) = 0.85; 95% confidence interval (CI) = 0.64, 1.07, moderate certainty), depression (SMD = 0.53; 95% CI = 0.34, 0.72, moderate certainty), anxiety (SMD = 0.29; 95% CI = 0.11, 0.48, moderate certainty), sleep quality (SMD = 0.34; 95% CI = 0.10, 0.57, low certainty) and mental functioning (SMD = 0.90; 95% CI = 0.50, 1.29, low certainty).

Compared with other active control therapies, TCME results in little to no difference in the severity of fatigue (SMD = 0.08; 95% CI = -0.18, 0.34, low certainty). For long-term outcomes, TCME may improve anxiety (SMD = 1.74; 95% CI = 0.44, 3.03, low certainty) compared to passive control. We did not identify TCME-related serious adverse events.

Conclusions: In patients with CFS, TCME probably reduces post-intervention fatigue, depression, and anxiety and may improve sleep quality and mental function compared with passive control, but has limited long-term effects. These findings will help health professionals and patients with better clinical decision-making.

Source: Kong L, Ren J, Fang S, Li Y, Wu Z, Zhou X, Hao Q, Fang M, Zhang YQ. Effects of traditional Chinese mind-body exercises for patients with chronic fatigue syndrome: A systematic review and meta-analysis. J Glob Health. 2023 Nov 24;13:04157. doi: 10.7189/jogh.13.04157. PMID: 37994837; PMCID: PMC10666566. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10666566/ (Full text)

Brain-regional characteristics and neuroinflammation in ME/CFS patients from neuroimaging: A systematic review and meta-analysis

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition characterized by an elusive etiology and pathophysiology. This study aims to evaluate the pathological role of neuroinflammation in ME/CFS by conducting an exhaustive analysis of 65 observational studies.

Four neuroimaging techniques, including magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), electroencephalography (EEG), and positron emission tomography (PET), were employed to comparatively assess brain regional structure, metabolite profiles, electrical activity, and glial activity in 1529 ME/CFS patients (277 males, 1252 females) and 1715 controls (469 males, 1246 females). Clinical characteristics, including sex, age, and fatigue severity, were consistent with established epidemiological patterns.

Regional alterations were most frequently identified in the cerebral cortex, with a notable focus on the frontal cortex. However, our meta-analysis data revealed a significant hypoactivity in the insular and thalamic regions, contrary to observed frequencies. These abnormalities, occurring in pivotal network hubs bridging reason and emotion, disrupt connections with the limbic system, contributing to the hallmark symptoms of ME/CFS.

Furthermore, we discuss the regions where neuroinflammatory features are frequently observed and address critical neuroimaging limitations, including issues related to inter-rater reliability. This systematic review serves as a valuable guide for defining regions of interest (ROI) in future neuroimaging investigations of ME/CFS

Source: Lee JS, Sato W, Son CG. Brain-regional characteristics and neuroinflammation in ME/CFS patients from neuroimaging: A systematic review and meta-analysis. Autoimmun Rev. 2023 Nov 26:103484. doi: 10.1016/j.autrev.2023.103484. Epub ahead of print. PMID: 38016575. https://www.sciencedirect.com/science/article/pii/S1568997223002185 (Full text)

A systematic review of quantitative EEG findings in Long COVID, Fibromyalgia and Chronic Fatigue Syndrome

Abstract:

Long COVID (LC) is a multisymptom clinical syndrome with similarities to Fibromyalgia Syndrome (FMS) and Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME). All these conditions are believed to be associated with centrally driven mechanisms such as central sensitisation.

There is a lack of consensus on quantitative EEG (qEEG) changes observed in these conditions. This review aims to synthesise and appraise the literature on resting-state qEEG in LC, FMS and CFS/ME, to help uncover possible mechanisms of central sensitisation in these similar clinical syndromes.

A systematic search of MEDLINE, Embase, CINHAL, PsycINFO and Web of Science databases for articles published between December 1994 and September 2023 was performed. Following screening for predetermined selection criteria and out of the initial 2510 studies identified, 17 articles were retrieved that met all the inclusion criteria, particularly of assessing qEEG changes in one of the three conditions compared to healthy controls. All studies scored moderate to high quality on the Newcastle-Ottawa scale.

There was a general trend for decreased low frequency EEG band activity (delta, theta, and alpha) and increased high-frequency EEG beta activity in FMS, whereas an opposite trend was found in CFS/ME. The limited LC studies included in this review focused mainly on cognitive impairments and showed mixed findings not consistent with patterns seen in FMS and CFS/ME.

Further research is required to explore whether there are phenotypes within LC that have EEG signatures similar to FMS or CFS/ME. This could inform identification of reliable diagnostic markers and possible targets for neuromodulation therapies.

Source: Bárbara Silva-Passadouro, Arnas Tamasauskas, Omar Khoja, Alexander J. Casson, Ioannis Delis, Christopher Brown, Manoj Sivan. A systematic review of quantitative EEG findings in Long COVID, Fibromyalgia and Chronic Fatigue Syndrome. medRxiv [Preprint] https://www.medrxiv.org/content/10.1101/2023.11.06.23298171v1.full-text (Full text)

Evaluation of viral infection as an etiology of ME/CFS: a systematic review and meta-analysis

Abstract:

Background: Myalgic encephalitis/chronic fatigue syndrome (ME/CFS) is a long-term disabling illness without a medically explained cause. Recently during COVID-19 pandemic, many studies have confirmed the symptoms similar to ME/CFS in the recovered individuals. To investigate the virus-related etiopathogenesis of ME/CFS, we conducted a systematic assessment of viral infection frequency in ME/CFS patients.

Methods: We conducted a comprehensive search of PubMed and the Cochrane Library from their inception through December 31, 2022, using selection criteria of viral infection prevalence in ME/CFS patients and controls. Subsequently, we performed a meta-analysis to assess the extent of viral infections’ contribution to ME/CFS by comparing the odds ratio between ME/CFS patients and controls (healthy and/or diseased).

Results: Finally, 64 studies met our eligibility criteria regarding 18 species of viruses, including a total of 4971 ME/CFS patients and 9221 control subjects. The participants included healthy subjects and individuals with one of 10 diseases, such as multiple sclerosis or fibromyalgia. Two DNA viruses (human herpes virus (HHV)-7 and parvovirus B19, including their co-infection) and 3 RNA viruses (borna disease virus (BDV), enterovirus and coxsackie B virus) showed odds ratios greater than 2.0 compared with healthy and/or diseased subjects. Specifically, BDV exceeded the cutoff with an odds ratio of ≥ 3.47 (indicating a “moderate association” by Cohen’s d test) compared to both healthy and diseased controls.

Conclusion: This study comprehensively evaluated the risk of viral infections associated with ME/CFS, and identified BDV. These results provide valuable reference data for future studies investigating the role of viruses in the causation of ME/CFS.

Source: Hwang, JH., Lee, JS., Oh, HM. et al. Evaluation of viral infection as an etiology of ME/CFS: a systematic review and meta-analysis. J Transl Med 21, 763 (2023). https://doi.org/10.1186/s12967-023-04635-0 https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-04635-0 (Full text)