Comparative Study Between Cognitive Phenotypes of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Multiple Sclerosis

Abstract:

Objective: Cognitive impairments are one of the most common and disabling symptoms associated with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Here, we address the possibility of a specific cognitive profile inherent to ME/CFS. Due to the occurrence of cognitive deficits, fatigue, and pain in both pathologies, multiple sclerosis (MS) is a relevant comparison model. For this purpose, we carried out a comparative study between cognitive profiles of patients with ME/CFS and patients suffering from MS.

Methods: In total, 40 ME/CFS and 40 MS patients were included. A complete screening of all cognitive functions was carried out through an extensive battery of tests routinely used in clinical practice.

Results: ME/CFS and MS patients showed deficits in episodic memory retrieval, visual selective attention and reading speed. ME/CFS patients also elicited a lower level of performance than MS patients regarding consolidation. For both groups, levels of performance on these cognitive tests did not correlate with levels of fatigue, pain, and depression.

Conclusions: This study highlighted both similarities and differences in the cognitive profiles of ME/CFS and MS patients. While both groups exhibited deficits in episodic memory retrieval, visual selective attention, and reading speed, ME/CFS patients showed distinct impairment in consolidation processes. These cognitive deficits were not correlated with fatigue, pain, or depression, reinforcing the hypothesis of intrinsic cognitive dysfunction in ME/CFS. These findings define a specific cognitive phenotype for ME/CFS, which could improve diagnostic accuracy and therapeutic strategies. Future research, particularly in functional imaging, may elucidate the neurobiological mechanisms underlying these impairments.

Source: Aoun Sebaiti M, Oubaya N, Gounden Y, Samson C, Lechapt E, Wahab A, Creange A, Hainselin M, Authier FJ. Comparative Study Between Cognitive Phenotypes of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Multiple Sclerosis. Diagnostics (Basel). 2025 Feb 17;15(4):487. doi: 10.3390/diagnostics15040487. PMID: 40002638. https://www.mdpi.com/2075-4418/15/4/487 (Full text)

A comparison of genome-wide association analyses of persistent symptoms after Lyme disease, fibromyalgia, and myalgic encephalomyelitis – chronic fatigue syndrome

Abstract:

Background: Up to 20% of Lyme disease cases experience post-treatment Lyme disease syndrome (PTLDS). The biological basis for PTLDS is poorly understood and no evidence-based treatment has been identified. Genetic studies have the potential to elucidate PTLDS pathophysiology and identify treatment targets.

Methods: We used electronic health record data (EHR) and genetic data from a linked biorepository to conduct a genome-wide association study (GWAS) for PTLDS among patients from a Pennsylvania health system. We evaluated the validity of the GWAS results in two separate conditions that have hypothesized overlapping pathophysiology, fibromyalgia and myalgic encephalomyelitis – chronic fatigue syndrome (ME/CFS). GWAS analyses were performed using logistic regression in SUGEN, assuming an additive genetic model, and adjusting for age, sex, array, and the first 10 principal components calculated from whole genome genotyping to adjust for ancestry, and accounting for relatedness including all 1st degree relationships. The functional mapping and annotation analysis (FUMA) tool was used to explore top findings from our GWAS.

Results: Among the 161,875 eligible MyCode participants with genotyping, there were 3,585 who met the criteria for treated Lyme disease. A subset of 695 (19.4%) of these patients met the criteria for PTLDS and the remaining 2890 were classified as controls. We identified two PTLDS loci that reached the suggestive significance threshold (P < 5 × 10– 7), with lead variants rs77857587, near IRX1, and rs10833979, near GAS2. Our top index single nucleotide polymorphism (SNP), rs77857587, is in high linkage disequilibrium with a long-range protein quantitative locus SNP, rs111774530, for the MARC2 (Mitochondrial Amidoxime Reducing Component 2) protein. We identified 5,041 cases of fibromyalgia (150,599 controls) and 2,268 cases of ME/CFS (151,594 controls) among the MyCode participants. Neither of the two suggestively significant loci were associated with fibromyalgia or ME/CFS.

Conclusion: We identified two PTLDS loci that reached a suggestive significance threshold. Our top index SNP is associated with the MARC2 protein, a protein that has been linked to multiple immune checkpoints. Further study is needed in a larger population to evaluate whether there is genetic evidence of the role of immune response in the occurrence of PTLDS.

Source: Hirsch AG, Justice AE, Poissant A, Nordberg CM, Josyula NS, Aucott J, Rebman AW, Schwartz BS. A comparison of genome-wide association analyses of persistent symptoms after Lyme disease, fibromyalgia, and myalgic encephalomyelitis – chronic fatigue syndrome. BMC Infect Dis. 2025 Feb 24;25(1):265. doi: 10.1186/s12879-024-10238-x. PMID: 39994562; PMCID: PMC11853495. https://pmc.ncbi.nlm.nih.gov/articles/PMC11853495/ (Full text)

Immunological and Antigenic Signatures Associated with Chronic Illnesses after COVID-19 Vaccination

Summary:

COVID-19 vaccines have prevented millions of COVID-19 deaths. Yet, a small fraction of the population reports a chronic debilitating condition after COVID-19 vaccination, often referred to as post-vaccination syndrome (PVS). To explore potential pathobiological features associated with PVS, we conducted a decentralized, cross-sectional study involving 42 PVS participants and 22 healthy controls enrolled in the Yale LISTEN study.

Compared with controls, PVS participants exhibited differences in immune profiles, including reduced circulating memory and effector CD4 T cells (type 1 and type 2) and an increase in TNFα+ CD8 T cells. PVS participants also had lower anti-spike antibody titers, primarily due to fewer vaccine doses. Serological evidence of recent Epstein-Barr virus (EBV) reactivation was observed more frequently in PVS participants. Further, individuals with PVS exhibited elevated levels of circulating spike protein compared to healthy controls.

These findings reveal potential immune differences in individuals with PVS that merit further investigation to better understand this condition and inform future research into diagnostic and therapeutic approaches.

Source: Bornali Bhattacharjee, Peiwen Lu, Valter Silva Monteiro, Alexandra Tabachnikova, Kexin Wang, William B. Hooper, Victoria Bastos, Kerrie Greene, Mitsuaki Sawano, Christian Guirgis, Tiffany J. Tzeng, Frederick Warner, Pavlina Baevova, Kathy Kamath, Jack Reifert, Danice Hertz, Brianne Dressen, Laura Tabacof, Jamie Wood, Lily Cooke, Mackenzie Doerstling, Shadan Nolasco, Amer Ahmed, Amy Proal, David Putrino, Leying Guan, Harlan M. Krumholz, Akiko Iwasaki. Immunological and Antigenic Signatures Associated with Chronic Illnesses after COVID-19 Vaccination

Possible Racial Disparities in the Diagnosis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Myalgic encephalomyelitis (ME/CFS) a chronic, disabling illness with no established etiopathology. It has been indicated in some population-based studies that Black and ethnic minority populations are underdiagnosed with ME/CFS. The aims of the present study were to (1) identify the agreement between receiving an ME/CFS diagnosis and meeting diagnostic criteria, (2) identify the demographic characteristics associated with receiving a diagnosis, and (3) explore patient satisfaction with healthcare.
Self-reported medical history and symptoms were collected via online survey from respondents with and without fatigue. The agreement between self-reporting an ME/CFS diagnosis and meeting the Center for Disease Control’s (CDC) ME/CFS criteria or Institute of Medicine (IOM) criteria was assessed with Cohen’s kappa. Patient characteristics predicting a physician diagnosis were analyzed with logistic regression. Associations between diagnosis, demographics, and healthcare satisfaction were assessed with chi-square tests of independence. There were 1110 responses. The agreement between meeting ME/CFS criteria and reporting an ME/CFS diagnosis was fair (CDC: κ = 0.29; SE = 0.02; IOM: κ = 0.28, SE = 0.03).
White respondents had 2.94 greater odds of being diagnosed with ME/CFS than non-White respondents. Having an ME/CFS diagnosis was associated with dissatisfaction with healthcare (χ2 (3, N = 1063) = 14.17, p = 0.003). The findings suggest racial disparities in the diagnostic processes for ME/CFS.
Source: Jones CL, Younger J. Possible Racial Disparities in the Diagnosis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). International Journal of Environmental Research and Public Health. 2025; 22(2):280. https://doi.org/10.3390/ijerph22020280 https://www.mdpi.com/1660-4601/22/2/280 (Full text)

Managing Energy, and Shaping Care: Insights from Adults with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Through Co-Production Workshops

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex, debilitating condition characterised by severe fatigue that is not relieved by rest and is often exacerbated by physical or mental activity. A key challenge for individuals with ME/CFS is energy management and to date, the only recommended strategy is “activity pacing.” This approach involves balancing activity and rest to avoid overexertion and minimise the risk of symptom exacerbation, commonly known as “post-exertional malaise”(PEM). A recent systematic review highlighted significant shortcomings in activity pacing interventions for ME/CFS, noting that they lacked rigour, were brief, and did not follow guidelines or integrate recommended technology, limiting their relevance for modern energy management. To address these gaps, the present study aimed to explore ME/CFS patients’ and health practitioners’ perspectives on approaches to energy management, how their understanding of energy management has evolved over time, and their recommendations for future interventions concerning energy management.

Method: Eight individuals with ME/CFS participated in six one-hour long online co-production workshops with two researchers, with the option to provide input through written responses. Additionally, three health practitioners shared their perspectives via email. Thematic analysis of the data identified several key recommendations for improving ME/CFS care.

Results and conclusions: Workshops highlighted the need for early support, healthcare provider training, and public education to combat stigma and misconceptions around ME/CFS. Participants emphasised patient collaboration, research-informed practices, rigorous research, multidisciplinary teams, and the integration of technologies like mHealth, along with a comprehensive approach including sleep, diet, and psychological support for better symptom management and activity pacing.

Source: Thornton EJ, Hayes LD, Goodwin DS, Sculthorpe N, Prior Y, Sanal-Hayes NEM. Managing Energy, and Shaping Care: Insights from Adults with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Through Co-Production Workshops. Am J Med. 2025 Feb 15:S0002-9343(25)00093-2. doi: 10.1016/j.amjmed.2025.02.008. Epub ahead of print. PMID: 39961545. https://www.amjmed.com/article/S0002-9343(25)00093-2/fulltext (Full text)

Mitochondrial Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

ME/CFS is a debilitating multisystem disorder of unclear etiology that affects many individuals worldwide. One of its hallmark symptoms is prolonged fatigue following exertion, a feature also observed in long COVID, suggesting an underlying dysfunction in energy production in both conditions. Here, mitochondrial dysfunction and its potential pathogenetic role in these disorders are reviewed.

Source: Syed AM, Karius AK, Ma J, Wang PY, Hwang PM. Mitochondrial Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Physiology (Bethesda). 2025 Feb 17. doi: 10.1152/physiol.00056.2024. Epub ahead of print. PMID: 39960432. https://journals.physiology.org/doi/abs/10.1152/physiol.00056.2024 (Full text available as PDF file)

CBT and graded exercise therapy studies have proven that ME/CFS and long COVID are physical diseases, yet no one is aware of that

Introduction:

The cognitive behavioral model (CBmodel) (Surawy et al., ; Vercoulen et al., ) has dominated the world of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) since the 1990s. According to this model, a belief in an organic illness, known as dysfunctional beliefs, stops ME/CFS patients engaging in normal activities, resulting in avoidance behavior and deconditioning. The deconditioning then leads to further avoidance behavior and more deconditioning. According to the CBmodel, symptoms of ME/CFS are caused by deconditioning and not by an underlying illness.

Cognitive behavioral therapy with graded activity (CBTplus) and graded exercise therapy (GET) were designed to reverse the dysfunctional beliefs, the avoidance behavior and the deconditioning and lead to recovery. However, an extensive review of the literature found that CBTplus and GET do not restore the ability to work (Vink and Vink-Niese, ). Additionally, there are now many papers documenting complex disruptions to the body’s physiology in ME/CFS, particularly involving immunological and inflammatory pathways, autonomic and neurological dysfunction, abnormalities in the cellular energy production and the gene expression (Committee on the Diagnostic Criteria for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, ; Liu et al., ; Missailidis et al., ).

Source: Vink M, Vink-Niese A. CBT and graded exercise therapy studies have proven that ME/CFS and long COVID are physical diseases, yet no one is aware of that. Front Hum Neurosci. 2025 Jan 29;19:1495050. doi: 10.3389/fnhum.2025.1495050. PMID: 39944089; PMCID: PMC11814198. https://pmc.ncbi.nlm.nih.gov/articles/PMC11814198/ (Full text)

Dietary Supplementation for Fatigue Symptoms in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)-A Systematic Review

Abstract:

Background/Objectives: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex neuroimmunological disorder with limited treatment options. Despite the widespread use of Dietary Supplements (DSs) among ME/CFS patients to alleviate fatigue and associated symptoms, evidence remains inconclusive. This systematic review aims to provide an updated synthesis of the efficacy of DS interventions and explore possible mechanisms underlying their therapeutic effects.

Methods: This systematic review was conducted according to PRISMA guidelines. Several databases (Ebsco Host, PubMed, Scopus, Google Scholar) were used for the systematic search, which was based on the broad search terms ME/CFS and DS with a focus on publications between 1994 and 2024. The primary outcome was fatigue, with additional considerations including psychological well-being, physical activity, and biochemical markers. Two independent researchers screened the studies for eligibility in a multi-stage process and assessed quality and bias using Cochrane’s risk of bias tools (RoB-2, ROBINS-I).

Results: Fourteen studies (N = 809) of heterogeneous designs were included, showing a high risk of bias, mostly due to missing data and selection bias. While some interventions (L-carnitine and guanidinoacetic acid, oxaloacetate, CoQ10-selenium combination, NADH and NADH-CoQ10 combination) showed significant reductions in fatigue, methodological limitations, like small sample sizes and missing data, prevent firm conclusions. Mixed results were reported for secondary outcomes like cognitive function and inflammatory markers. Six studies noted adverse effects, including nausea and insomnia.

Conclusions: Though some DSs showed potential in reducing fatigue in ME/CFS, methodological limitations and inconsistent results hinder definitive conclusions. Future research should improve diagnostic criteria and include more diverse populations.

Source: Dorczok MC, Mittmann G, Mossaheb N, Schrank B, Bartova L, Neumann M, Steiner-Hofbauer V. Dietary Supplementation for Fatigue Symptoms in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)-A Systematic Review. Nutrients. 2025 Jan 28;17(3):475. doi: 10.3390/nu17030475. PMID: 39940333; PMCID: PMC11819863. https://pmc.ncbi.nlm.nih.gov/articles/PMC11819863/ (Full text)

Language Matters: What Not to Say to Patients with Long COVID, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, and Other Complex Chronic Disorders

Abstract:

People with Long COVID, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and other complex chronic disorders consistently report having difficulty obtaining effective and compassionate medical care and being disbelieved, judged, gaslighted, and even dismissed by healthcare professionals. We believe that these adversarial interactions and language are more likely to arise when healthcare professionals are confronting complex chronic illnesses without proper training, diagnostic biomarkers, or FDA-approved therapies.
These problematic conversations between practitioners and patients often involve specific words and phrases—termed the “never-words”—can leave patients in significant emotional distress and negatively impact the clinician–patient relationship and recovery. Seeking to prevent these destructive interactions, we review key literature on best practices for difficult clinical conversations and discuss the application of these practices for people with Long COVID, ME/CFS, dysautonomia, and other complex chronic disorders. We provide recommendations for alternative, preferred phrasing to the never-words, which can enhance therapeutic relationship and chronic illness patient care via compassionate, encouraging, and non-judgmental language.
Source: Smyth NJ, Blitshteyn S. Language Matters: What Not to Say to Patients with Long COVID, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, and Other Complex Chronic Disorders. International Journal of Environmental Research and Public Health. 2025; 22(2):275. https://doi.org/10.3390/ijerph22020275 https://www.mdpi.com/1660-4601/22/2/275 (Full text)

Mapping the Complexity of ME/CFS: Evidence for Abnormal Energy Metabolism, Altered Immune Profile and Vascular Dysfunction

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disorder with no known underlying mechanisms, diagnostic tools, or treatments.  Multiple areas of dysfunction have been extensively studied, but rarely examined together. We recruited age- and sex-matched ME/CFS patients and healthy controls for a multi-modal study examining energy metabolism, immune profiles and plasma protein levels.

Elevated levels of adenosine monophosphate (AMP) were detected in both plasma and immune cells. Additionally, immune cells showed higher levels of adenosine diphosphate (ADP) and a reduced adenosine triphosphate/adenosine diphosphate (ATP/ADP) ratio.

These findings imply decreased ATP generation and the presence of energy stress within the immune cell population. Adaptive immune cell populations were skewed towards less mature effector subsets of CD4+, CD8+ and gd T cells, and proportions of CD1c+CD141-conventional DC type 2 (cDC2) and CD56lowCD16+ terminal natural killer (NK) cells were also reduced. Elevated levels of plasma proteins associated with thrombus formation and vascular reactivity may contribute to the endothelial dysfunction observed in ME/CFS patients. Using Classification and Regression Tree (CART) modelling, we identified variables from each mode of investigation with strong predictive potential for ME/CFS. Together, this study provides new insights into the somatic symptoms and underlying biology of ME/CFS.

Source: Heng, Ruiwen Benjamin and Gunasegaran, Bavani and Krishnamurthy, Shivani and Bustamante, Sonia and Staats, Ananda and Chow, Sharron and Ahn, Seong Beom and Paul-Heng, Moumita and Maciver, Yolande and Smith, Kirsten and Tran, Denise Phuong and Howley, Peter P. and Bilgin, Ayse Aysin and Sharland, Alexandra and Schloeffel, Richard and Guillemin, Gilles J. and Administrator, Sneak Peek, Mapping the Complexity of ME/CFS: Evidence for Abnormal Energy Metabolism, Altered Immune Profile and Vascular Dysfunction. Available at SSRN: https://ssrn.com/abstract=5131664 or http://dx.doi.org/10.2139/ssrn.5131664  https://papers.ssrn.com/sol3/papers.cfm?abstract_id=5131664 (Full text available as PDF file)