Assessment of symptoms in myalgic encephalomyelitis/chronic fatigue syndrome: a comparative study of existing scales

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multifaceted disorder characterized by persistent fatigue, post-exertional malaise (PEM), cognitive dysfunction, sleep disturbance, pain, psychological distress, orthostatic intolerance, and impaired multidimensional health status and functioning. In the absence of reliable biomarkers, standardized symptom assessment is essential for accurate diagnosis and comparability across studies.

This narrative literature review synthesized studies identified through PubMed and Web of Science up to June 2024, covering assessment instruments across major ME/CFS symptom domains. Tools were evaluated for their psychometric validity, clinical applicability, and key limitations.

Overall, existing scales demonstrate acceptable reliability but vary in sensitivity and disease specificity. Harmonized, multidimensional, and digitally or objectively validated measures are needed to improve diagnostic precision, longitudinal monitoring, and clinical translation in ME/CFS.

Source: Lu J, Sun W, Li S, Qu Y, Liu T, Guo S, Feng C, Yang T. Assessment of symptoms in myalgic encephalomyelitis/chronic fatigue syndrome: a comparative study of existing scales. Front Neurol. 2025 Nov 18;16:1618272. doi: 10.3389/fneur.2025.1618272. PMID: 41341517; PMCID: PMC12668935. https://pmc.ncbi.nlm.nih.gov/articles/PMC12668935/ (Full text)

Differential Characteristics and Comparison Between Long-COVID Syndrome and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Long-COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome are disabling diseases characterised by ongoing fatigue, post-exertional malaise, cognitive impairment, and autonomic dysfunction. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome typically follows viral infections, whereas Long-COVID exclusively follows SARS-CoV-2 infection, with overlapping but distinct features. This review uses comprehensive searches of online databases to compare their clinical presentations, pathophysiologies, and treatments.

Both Long-COVID and ME/CFS appear to involve multifactorial mechanisms, including viral persistence, immune dysregulation, endothelial dysfunction, and autoimmunity, though their relative contributions remain uncertain. Symptom management strategies are consistent, however. Cognitive behaviour therapy has been successful, and there are minimal drug treatments. Graded exercise therapy occupies a contested place, recommending individualised pacing and multidisciplinary rehabilitation.

Common and exclusive mechanisms must be identified to formulate valuable therapies. A more significant body of research focusing on immune dysfunction as a pathogenic mechanism for advancing the disease and enabling more effective therapies and diagnostics is needed.

Source: Ivanovska M, Homadi MS, Angelova G, Taskov H, Murdjeva M. Differential Characteristics and Comparison Between Long-COVID Syndrome and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Biomedicines. 2025 Nov 17;13(11):2797. doi: 10.3390/biomedicines13112797. PMID: 41301889; PMCID: PMC12650534. https://pmc.ncbi.nlm.nih.gov/articles/PMC12650534/ (Full text)

The Role of Nuclear and Mitochondrial DNA in Myalgic Encephalomyelitis: Molecular Insights into Susceptibility and Dysfunction

Abstract:

Myalgic Encephalomyelitis (ME), also known as chronic fatigue syndrome (CFS), is a debilitating and heterogeneous disorder marked by persistent fatigue, post-exertional malaise, cognitive impairment, and multisystem dysfunction. Despite its prevalence and impact, the molecular mechanisms underlying ME remain poorly understood.
This review synthesizes current evidence on the role of DNA, both nuclear and mitochondrial, in the susceptibility and pathophysiology of ME. We examined genetic predispositions, including familial clustering and candidate gene associations, and highlighted emerging insights from genome-wide and multi-omics studies.
Mitochondrial DNA variants and oxidative stress-related damage are discussed in relation to impaired bioenergetics and symptom severity. Epigenetic modifications, particularly DNA methylation dynamics and transposable element activation, are explored as mediators of gene–environment interactions and immune dysregulation.
Finally, we explored the translational potential of DNA-based biomarkers and therapeutic targets, emphasizing the need for integrative molecular approaches to advance diagnosis and treatment. Understanding the DNA-associated mechanisms in ME offers a promising path toward precision medicine in post-viral chronic diseases.
Source: Elremaly W, Elbakry M, Vahdani Y, Franco A, Moreau A. The Role of Nuclear and Mitochondrial DNA in Myalgic Encephalomyelitis: Molecular Insights into Susceptibility and Dysfunction. DNA. 2025; 5(4):53. https://doi.org/10.3390/dna5040053 https://www.mdpi.com/2673-8856/5/4/53 (Full text)

The Gut-Brain-Immune Axis in Environmental Sensitivity Illnesses: Microbiome-Centered Narrative Review of Fibromyalgia Syndrome, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, and Multiple Chemical Sensitivity

Abstract:

Environmental sensitivity illnesses-including fibromyalgia syndrome (FMS), myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and multiple chemical sensitivity (MCS)-are chronic, disabling disorders characterized by hypersensitivity to environmental stimuli, persistent fatigue, widespread pain, and neurocognitive and autonomic dysfunction. Although their diagnostic criteria differ, increasing evidence suggests overlapping clinical features and shared biological mechanisms. A unifying hypothesis highlights the gut-brain-immune axis, where alterations in the intestinal microbiome, epithelial barrier dysfunction, and aberrant immune signaling interact with central sensitization and systemic metabolic dysregulation.

Recent studies demonstrate reduced microbial diversity, depletion of anti-inflammatory taxa (e.g., Faecalibacterium prausnitziiBifidobacterium), and enrichment of pro-inflammatory Clostridium species across these conditions. These shifts likely alter production of short-chain fatty acids, amino acid metabolites, and complex lipids, with downstream effects on mitochondrial function, neuroinflammation, and host energy metabolism. Moreover, emerging clinical interventions-including probiotics, prebiotics, synbiotics, and fecal microbiota transplantation-suggest a potential role for microbiome-targeted therapies, though controlled evidence remains limited.

This review synthesizes current knowledge on microbiome alterations in FMS, ME/CFS, and MCS, emphasizing their convergence on metabolic and immune pathways. By integrating microbial, immunological, and neurophysiological perspectives, we propose a microbiome-centered framework for understanding environmental sensitivity illnesses and highlight avenues for translational research and therapeutic innovation.

Source: Watai K, Taniguchi M, Azuma K. The Gut-Brain-Immune Axis in Environmental Sensitivity Illnesses: Microbiome-Centered Narrative Review of Fibromyalgia Syndrome, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, and Multiple Chemical Sensitivity. Int J Mol Sci. 2025 Oct 14;26(20):9997. doi: 10.3390/ijms26209997. PMID: 41155291. https://www.mdpi.com/1422-0067/26/20/9997 (Full text)

Telehealth as a care solution for homebound people: systematic review and meta-analysis of healthcare utilization, quality of life, and well-being outcomes

Abstract:

Homebound individuals residing in community settings with severe health conditions and disabilities could arguably benefit from telehealth interventions. However, the effectiveness of telehealth compared to in-person care remains underexplored, considering the diversity of these groups. This systematic review and meta-analysis aimed to evaluate the effectiveness of telehealth in reducing healthcare utilization and improving health-related quality of life (HRQOL) and well-being in homebound populations.

Adhering and expanding on a published protocol, we conducted comprehensive search across multiple databases: MEDLINE, Embase, PsycINFO, CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, LILACS, and the Web of Science, with no restrictions on language or publication date, and experimental and quasiexperimental studies considered. Eleven independent reviewers were responsible for study selection, and three for data extraction. The methodological quality of the included studies was assessed using JBI checklists. A meta-analysis was then performed using Stata software, which reported standardized mean differences (SMDs) as the effect measure, with the quality of evidence evaluated using the GRADE approach. From an initial screening of 3289 articles, ten studies met our inclusion criteria, with eight suitable for meta-analysis. These studies encompassed data from 2245 participants.

Our findings revealed that telehealth interventions significantly reduced healthcare utilization (SMD: −0.49; 95% CI: −0.76 to −0.22; p < 0.01, GRADE: low certainty), significantly enhanced HRQOL (SMD: 0.18; 95% CI: 0.01 to 0.35; p = 0.04, GRADE: moderate certainty), and significantly improved well-being (SMD: −0.31; 95% CI: −0.47 to −0.15; p < 0.01, GRADE: moderate certainty) compared to in-person care. Thus, telehealth emerges as a viable alternative to conventional care, significantly reducing healthcare utilization and enhancing both HRQOL and well-being for homebound people.

These findings underscore the potential of telehealth to mitigate healthcare disparities and emphasize the need for accessible, equitable telehealth services codeveloped with end users and relevant stakeholders to save resources and maximize health outcomes for vulnerable populations in community settings.

Source: Pinero de Plaza, Maria AlejandraGulyani, AartiBulto, Lemma N.Allande-Cussó, ReginaPearson, VincentLange, BelindaMarin, TaniaGebremichael, LemlemBrown, ShannonDafny, HilaSajeev, SheldaBulamu, NormaBeleigoli, AllineNesbitt, KatieMcMillan, PenelopeClark, RobynTieu, MatthewKitson, AlisonChampion, StephanieHines, SoniaHendriks, Jeroen M.Telehealth as a Care Solution for Homebound People: Systematic Review and Meta-Analysis of Healthcare Utilization, Quality of Life, and Well-Being OutcomesHealth & Social Care in the Community2025, 7224151, 32 pages, 2025. https://doi.org/10.1155/hsc/7224151 https://onlinelibrary.wiley.com/doi/full/10.1155/hsc/7224151 (Full text)

Understanding Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Physical Fatigue Through the Perspective of Immunosenescence

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating illness marked by persistent fatigue, yet its mechanisms remain unclear. Growing evidence implicates immunosenescence-the age-related decline in immune function-in the onset and persistence of fatigue.

Methods: This review synthesizes clinical and experimental data to examine how immunosenescence contributes to ME/CFS. We focus on chronic inflammation, senescent immune phenotypes, mitochondrial dysfunction, and neuroendocrine imbalance, with emphasis on maladaptive crosstalk among immune, muscular, neuroendocrine, and vascular systems.

Results: Aging immune cells drive chronic inflammation that impairs mitochondrial ATP production and promotes muscle catabolism. Concurrently, HPA-axis suppression and β2-adrenergic dysfunction amplify immune dysregulation and energy imbalance. Together, these processes illustrate how immunosenescence sustains pathological cross-organ signaling underlying systemic fatigue.

Conclusion: Immunosenescence provides a unifying framework linking immune, metabolic, and neuroendocrine dysfunction in ME/CFS. Recognizing cross-organ communication highlights its clinical relevance, suggesting biomarkers such as cytokines and exhaustion markers, and supports integrated therapeutic strategies targeting immune and metabolic networks.

Source: Luo Y, Xu H, Xiong S, Ke J. Understanding Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Physical Fatigue Through the Perspective of Immunosenescence. Compr Physiol. 2025 Oct;15(5):e70056. doi: 10.1002/cph4.70056. PMID: 41017304. https://pubmed.ncbi.nlm.nih.gov/41017304/

Gulf War Illness, Fibromyalgia, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Long COVID Overlap in Common Symptoms and Underlying Biological Mechanisms: Implications for Future Therapeutic Strategies

Abstract:

Although Gulf War Illness (GWI), fibromyalgia (FM), myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and long COVID have distinct origins, in this article we have reviewed evidence that these disorders comprise a group of so-called low-energy associated disorders with overlapping common symptoms underlying pathology.

In particular, evidence for mitochondrial dysfunction, oxidative stress, inflammation, immune dysregulation, neuroendocrine dysfunction, disrupted brain-gut-microbiome axis, apoptosis/ferroptosis and telomere shortening as common features in the pathogenesis of these disorders has been identified.

Given the role of coenzyme Q10 (CoQ10) in promoting normal mitochondrial function, as an antioxidant, antiinflammatory and antiapoptotic and antiferroptotic agent, there is a rationale for supplementary CoQ10 in the management of these disorders. The reported benefits of supplementary CoQ10 administration in GWI, FM, ME/CFS and long COVID have been reviewed; the potential benefit of supplementary CoQ10 in reducing telomere shortening and improving the efficiency of stem cell transfer relevant has also been identified as promising therapeutic strategies in these disorders.

This review advances beyond previous systematic reviews and consensus statements on overlapping similar symptoms and underlying biological pathomechanisms in these complex disorders.

Source: Mantle D, Domingo JC, Golomb BA, Castro-Marrero J. Gulf War Illness, Fibromyalgia, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Long COVID Overlap in Common Symptoms and Underlying Biological Mechanisms: Implications for Future Therapeutic Strategies. Int J Mol Sci. 2025 Sep 17;26(18):9044. doi: 10.3390/ijms26189044. PMID: 41009608. https://www.mdpi.com/1422-0067/26/18/9044 (Full text)

Endometriosis and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Systematic Review and Meta-Analysis

Abstract:

Background/Objectives: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and endometriosis are debilitating conditions that share overlapping features of chronic inflammation and immune dysregulation, yet their epidemiological relationship remains poorly characterized. The objective of this study was to investigate the association between ME/CFS and endometriosis, examining shared risk factors, clinical correlates, and epidemiological patterns.

Methods: We conducted a systematic review and meta-analysis. Two independent reviewers screened 236 records after duplicate removal, with seventeen studies undergoing full-text review and thirteen meeting inclusion criteria for meta-analysis. Data were extracted using standardized forms and analyzed using random-effects models in R, with heterogeneity assessed using I2 statistics and the risk of bias evaluated using the JBI critical appraisal tool.

Results: Our meta-analysis of five studies (n = 2261 participants) revealed that women with endometriosis had 2.79-fold higher odds (95% CI: 2.00-3.89) of developing ME/CFS compared to controls. Similarly, our fixed-effects meta-analysis of two studies assessing the association of ME/CFS and endometriosis yielded a pooled OR of 2.52 (95% CI: 2.45-2.60, p < 0.001). There was minimal statistical heterogeneity (I2 = 0.0%, p > 0.7969) for both meta-analyses.

Conclusions: This study demonstrates a significant bidirectional association between endometriosis and ME/CFS, driven by shared mechanisms of immune dysregulation and chronic inflammation. Despite high heterogeneity, the consistent effect sizes support clinical vigilance for comorbidity. Future research should prioritize standardized diagnostic criteria to elucidate causal pathways. These findings underscore the need for integrated care approaches to address overlapping symptomatology in affected patients.

Source: Compton S, Alkabalan R, Cadet J, Mastali A, Ramdass PVAK. Endometriosis and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Systematic Review and Meta-Analysis. Diagnostics (Basel). 2025 Sep 15;15(18):2332. doi: 10.3390/diagnostics15182332. PMID: 41008704. https://www.mdpi.com/2075-4418/15/18/2332 (Full text)

Burden of Disease in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Scoping Review

Abstract:

Objective: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a serious chronic and complex multi-system disease characterised by symptoms such as post-exertional malaise, fatigue, cognitive impairment and pain. Diagnosis is based on international consensus criteria, and no curative treatment is available. In the USA, its prevalence is estimated at 0.42% among adults, with women affected three times as often as men. Prevalence is expected to increase due to the COVID-19 pandemic. In addition to its severe symptoms, ME/CFS has a substantial economic impact. This scoping review aimed to systematically examine the global health, social and economic burden of ME/CFS.

Methods: We conducted a systematic literature search following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Reviews (PRISMA-ScR) guidelines in six databases and supplemented it with a citation search. We assessed study quality using a modified version of the Mixed Methods Appraisal Tool.

Results: We included 20 studies that assessed costs (n = 16), disability-adjusted life years (DALYs) (n = 3), employment rates (n = 1), and school attendance (n = 1) as indicators of disease burden. Reported costs per patient ranged from USD 2,916 to USD 119,611, with indirect costs accounting for the largest proportion. DALYs reported for the USA ranged from 0.714 million in 2016 to 5.77 million in 2022.

Conclusion: ME/CFS imposes a substantial health, social and economic burden of disease. Discrepancies in estimates are probably due to differences in study samples, methodologies, cost components, and healthcare systems. Because ME/CFS is assumed to be underdiagnosed, its true burden may be even higher.

Source: Vester P, Boudouroglou-Walter S, Schreyögg J, Wieting C, Blome C. Burden of Disease in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Scoping Review. Appl Health Econ Health Policy. 2025 Sep 23. doi: 10.1007/s40258-025-01006-2. Epub ahead of print. PMID: 40986167. https://link.springer.com/article/10.1007/s40258-025-01006-2 (Full text)

Metabolic neuroimaging of myalgic encephalomyelitis/chronic fatigue syndrome and Long-COVID

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Long-COVID are complex, disabling conditions that have emerged as significant public health challenges, affecting millions worldwide. Despite their growing prevalence, effective diagnostics and treatments remain limited, largely due to an incomplete understanding of their underlying pathophysiology. Both conditions share hallmark symptoms of chronic fatigue, cognitive dysfunction, and postexertional malaise, but their biological underpinnings remain to be elucidated. Neuroimaging offers a promising, noninvasive window into the brain’s metabolic landscape and has the potential to uncover objective biomarkers for these conditions.

In this mini review, we highlight recent advancements in metabolic neuroimaging, particularly positron emission tomography and magnetic resonance imaging/magnetic resonance spectroscopy, that reveal alterations in glucose and oxygen metabolism, neurotransmitter balance, and oxidative stress. These insights point toward shared disruptions in brain energy metabolism and neuroinflammatory processes, which may underlie the persistent symptoms in both ME/CFS and Long-COVID.

Importantly, while some findings overlap, inconsistencies in metabolite profiles between ME/CFS and Long-COVID underscore the need for further stratification and longitudinal research. Standardizing definitions, such as identifying Long-COVID patients who meet ME/CFS diagnostic criteria, could help improve study comparability.

By summarizing current imaging evidence, this review underscores the potential of neuroimaging to identify imaging biomarkers to advance the clinical diagnosis of Long-COVID and identify therapeutic targets for treatment development. As we continue to face the growing burden of Long-COVID and ME/CFS, metabolic imaging may serve as a powerful tool to bridge gaps in knowledge and accelerate progress toward effective care.

Source: Zhu Y, Quan P, Yamazaki T, Norweg A, Natelson B, Xu X. Metabolic neuroimaging of myalgic encephalomyelitis/chronic fatigue syndrome and Long-COVID. Immunometabolism (Cobham). 2025 Sep 12;7(4):e00068. doi: 10.1097/IN9.0000000000000068. PMID: 40958852; PMCID: PMC12435251. https://pmc.ncbi.nlm.nih.gov/articles/PMC12435251/ (Full text)