Tag: 2026

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome diagnostic reporting in the 2021-2023 National Health Interview Survey

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic disabling illness characterized by activity limitations associated with fatigue, post-exertional malaise (PEM), unrefreshing sleep, memory and concentration problems, orthostatic intolerance and painful discomfort. While typically considered to be a chronic condition, some persons who have had ME/CFS report no longer having the disorder. Here, the prevalence and characteristics of adults in the United States who self-report having an ME/CFS diagnosis and those who self-report no longer having ME/CFS are presented.

Methods: The current study utilized publicly available data from the 2021-2023 National Health Interview Survey, which interviewed 86,655 United States civilian non-institutionalized adults about their health. For this study, participants were categorized into three groups: Current ME/CFS (individuals currently diagnosed with ME/CFS), Past ME/CFS (individuals who were previously diagnosed but no longer report having the condition), and Never ME/CFS (individuals who have never been diagnosed with ME/CFS). These groups were characterized using descriptive statistics.

Results: In the United States adult population, 20.7% of the estimated 1.5% adults who ever received an ME/CFS diagnosis report they no longer have the condition (Past ME/CFS). Overall the Past ME/CFS group reported experiencing symptoms less frequently, less difficulty with daily living, approximately equal prevalence of comorbidities, and better general health status than the Current ME/CFS group but remained significantly impaired compared to the Never ME/CFS group. However, 40-50% of adults with Past ME/CFS report symptoms and function similar to adults with Current ME/CFS and only approximately 25% had substantially less symptoms and better function compared to those with Current ME/CFS. Comorbidities did not differ significantly between the Current and Past ME/CFS groups.

Conclusion: Further study to better understand the reasons why those in the Past ME/CFS group report no longer having the disorder is important for understanding the natural history and disease burden of ME/CFS. Studying symptomatic remissions, and the underlying physiology of improvement, could lead to identification of new disease modifying therapeutic approaches.

Source: Fleig K, Nahin R, Stussman B, Wilkerson M, Unger ER, Lin JS, Walitt B. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome diagnostic reporting in the 2021-2023 National Health Interview Survey. BMC Public Health. 2026 May 8. doi: 10.1186/s12889-026-27598-5. Epub ahead of print. PMID: 42104344. https://link.springer.com/article/10.1186/s12889-026-27598-5 (Full text available as PDF file)

Interpreting hand grip strength in hospital employees with post-COVID syndrome compared to non-infected controls: a case-control study

Abstract:

Post-COVID syndrome (PCS) is characterized by a variety of persistent symptoms following SARS-CoV-2 infection, including fatigue among others. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a related neurological disorder primarily characterized by severe fatigue and post-exertional malaise. This exploratory study aimed to assess hand grip strength (HGS) in individuals with PCS to evaluate muscular performance and fatigability and to explore potential HGS-derived parameters associated with PCS.

HGS was measured in 19 hospital employees with PCS (mean age 47.8; 89.5% female; 7 fulfilling ME/CFS criteria) and compared with 23 healthy controls (mean age 43.7; 69.6% female). Measurements were performed in two sessions separated by 60 min, each consisting of ten consecutive HGS measurements. Linear mixed model analysis indicated that HGS tended to be lower in PCS at specific measurement points, although no consistent overall group effect was observed. HGS was reduced in the second session in PCS but not in controls, suggesting possible alterations in recovery following repeated exertion.

Exploratory analysis of 30 HGS-derived parameters using logisitic regression models in female participants identified parameters based on maximum, minimum, and mean force values as showing the most promising discriminatory patterns: however, predictive performace was moderate and should be interpreted with caution.

Overall, HGS may provide insights into funcitional impairment in PCS and could serve as a supportive adjunct in clinical assessment, although its diagnostic utility requires validation in larger cohorts.

Source: Tack M, Gruber R, Betting L, Herbrandt S, Schlang G, Mattner F. Interpreting hand grip strength in hospital employees with post-COVID syndrome compared to non-infected controls: a case-control study. Sci Rep. 2026 May 9. doi: 10.1038/s41598-026-51666-w. Epub ahead of print. PMID: 42103832. https://www.nature.com/articles/s41598-026-51666-w (Full study available as PDF file)

Chronic stress and cognitive dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome: HPA axis dysregulation and hippocampal plasticity

Abstract:

Cognitive dysfunction is a common and disabling clinical feature of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), often described by patients as “brain fog.” These symptoms typically manifest as difficulties in attention, memory, and concentration. Chronic stress has been proposed as an important contributing factor in ME/CFS.

The hypothalamic-pituitary-adrenal (HPA) axis plays a central role in the stress response, and prolonged adverse stress may contribute to HPA axis dysregulation, including altered cortisol rhythmicity and impaired negative feedback regulation. Such dysregulation may be associated with cognitive dysfunction in ME/CFS through mechanisms involving neuroinflammatory responses, oxidative stress, and disturbances in neurotransmitter homeostasis. Studies suggest that these alterations may affect hippocampal structure and function, thereby contributing to impaired learning and memory processes.

As a key brain region involved in cognition and stress regulation, the hippocampus may be implicated in the neurobiological mechanisms underlying cognitive dysfunction in ME/CFS. This review integrates current evidence on the potential role of HPA axis dysregulation and related neurobiological alterations in chronic stress-associated cognitive dysfunction in ME/CFS, with the aim of providing a theoretical basis for identifying potential intervention targets and informing strategies centered on HPA axis regulation.

Source: Kang H, Shao T, Shi Y, Wang S, Xiong H, Jin X, Ren J. Chronic stress and cognitive dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome: HPA axis dysregulation and hippocampal plasticity. Front Neurosci. 2026 Apr 22;20:1814098. doi: 10.3389/fnins.2026.1814098. PMID: 42100733; PMCID: PMC13144083. https://pmc.ncbi.nlm.nih.gov/articles/PMC13144083/ (Full text)

Erythroid-hormonal axis in long COVID

Abstract:

Long COVID may reflect a failure of coordinated physiological recovery rather than persistent infection. Emerging evidence identifies inflammation-driven disruption of erythropoiesis and hormonal balance as central mechanisms linking immune dysregulation, metabolic stress, and persistent symptoms. This framework positions erythroid-endocrine pathways as key determinants of recovery and promising therapeutic targets.

Source: Elahi S. Erythroid-hormonal axis in long COVID. Trends Mol Med. 2026 May 4:S1471-4914(26)00088-2. doi: 10.1016/j.molmed.2026.04.006. Epub ahead of print. PMID: 42086409. https://pubmed.ncbi.nlm.nih.gov/42086409/

Risk factors for severe post-COVID condition in children, adolescents, and young adults

Abstract:

Post-COVID condition (PCC) in children and young people (CYP, PCCcyp) remains a significant health burden. Early identification of patients at risk for severe disease, including myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), is crucial for timely and adequate care. This monocentric, observational registry study, performed at a tertiary pediatric hospital in Germany, included CYP aged 7-25 years with PCCcyp at diagnosis. Standardized clinical assessment tools and patient-reported outcome measures were applied, including the novel Munich Long COVID Symptom Questionnaire (MLCSQ).

Severe PCC was defined by chronic symptom clusters, Fatigue Severity Scale (FSS), Total Composite Autonomic Symptom Score-31 (COMPASS-31), SF-36 composite scores, Bell Score, and confirmed ME/CFS diagnosis. Among 120 participants, severe PCCcyp was associated with a higher number of acute symptoms (ORadj 1.22, P < 0.001), acute orthostatic intolerance (ORadj 9.87, P = 0.002), acute trouble concentrating (ORadj 11.8, P = 0.005), and female sex (OR 3.31, P = 0.031).

Categorizing acute symptoms at a threshold of ≥ 12 yielded optimal model performance (AUC 0.857; sensitivity 65.6%; specificity 90.2%). ME/CFS was diagnosed in 24% of participants, all within the severe PCCcyp cluster, and was characterized by greater acute symptom complexity, more fatigue, more autonomic symptoms, and poorer function.

Conclusions: The number and pattern of acute symptoms during SARS-CoV-2 infection may serve as early, specific predictors of severe PCCcyp. Patients with ≥ 12 acute symptoms should be closely monitored to enable early diagnosis of severe PCCcyp and ME/CFS. A distinct cluster of severely affected patients, frequently with ME/CFS, was identified.

Trial registration: ClinicalTrials.gov: NCT05638724; Ethics approval (511/21, 2025-465-S-SB).

Source: Donath Q, Haegele M, Schindler D, Welzhofer T, Christa C, Grabbe A, Leone A, Ilhan C, Weidmann C, Eberhartinger M, Bechtold S, Bursch N, Wolf H, Hieber H, Peo LC, Bucka LA, Stojanov S, Warlitz C, Alberer M, Gerrer K, Hausruckinger A, Mittelstrass K, Wendtner CM, Hoechstetter MA, Grübl A, Toepfner N, Pricoco R, Scheibenbogen C, Mihatsch LL, Behrends U. Risk factors for severe post-COVID condition in children, adolescents, and young adults. Eur J Pediatr. 2026 May 4;185(5):344. doi: 10.1007/s00431-026-06995-3. PMID: 42082813. https://link.springer.com/article/10.1007/s00431-026-06995-3 (Full text available as PDF file)

Involvement of autoantibodies against G protein-coupled receptors in post-COVID condition and Chronic Fatigue Syndrome

Abstract:

Post-COVID condition (PCC) and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) are chronic disorders marked by fatigue, autonomic dysfunction, and cognitive impairment. Autoantibodies (AAbs) targeting adrenergic and muscarinic receptors have been implicated in their pathophysiology. This study aimed to investigate the association between these AAbs, autonomic nervous system (ANS) function, and cognitive performance in PCC and ME/CFS.

We included 96 PCC patients, 59 ME/CFS patients, and 36 healthy controls (HCs). Plasma AAbs against α1, β1, β2 adrenergic and M1-M4 muscarinic receptors were measured via ELISA. ANS function was evaluated using COMPASS-31, Sudoscan, hemodynamic tests (deep breathing, Valsalva, tilt test), and heart rate variability. Cognitive domains assessed included attention, fluency, processing speed, memory, visuoconstruction, perception, and executive functions.

ME/CFS patients had significantly higher β2 adrenergic AAb titers than PCC and HCs (F₂,₁₈₆ = 3.15, p = 0.046). PCC patients showed more borderline/pathological M3 muscarinic AAb results compared to HCs. β2 AAb levels correlated with increased autonomic symptoms in PCC (r = 0.27, p = 0.048) and sympathovagal imbalance in ME/CFS (r = 0.45, p = 0.001). In ME/CFS, M1, M3, and M4 AAb titers positively correlated with verbal and working memory performance.

Distinct AAb profiles in PCC and ME/CFS suggest potential differences in immunological mechanisms. β2 adrenergic receptor AAbs were associated with measures of autonomic dysfunction in PCC patients, and with sympathovagal parameters in ME/CFS patients. Muscarinic AAbs were correlated with cognitive performance in ME/CFS, supporting a potential role of these autoantibodies in autonomic and cognitive dysfunction. These findings support further investigation of AAbs as biomarkers and therapeutic targets.

Source: Azcue N, Prada A, Del Pino R, Acera M, Fernández-Valle T, Ayo-Mentxakatorre N, Pérez-Concha T, Murueta-Goyena A, Lafuente JV, López de Munain A, Ruiz Irastorza G, Ribacoba L, Gabilondo I, Tijero-Merino B, Gómez-Esteban JC. Involvement of autoantibodies against G protein-coupled receptors in post-COVID condition and Chronic Fatigue Syndrome. Sci Rep. 2026 May 5. doi: 10.1038/s41598-026-49131-9. Epub ahead of print. PMID: 42082542. https://www.nature.com/articles/s41598-026-49131-9 (Full text available as PDF file)

‘I Want Everyone to Have It, and Everyone to Be on It’: A Feasibility Study of the Transforming Long Covid Intervention

Abstract:

Background: An understanding of the nature of long Covid (LC) is evolving, with recent evidence highlighting the role of increased sympathetic activation and decreased parasympathetic response. Building upon this emerging science, the ‘Transforming Long COVID’ (TLC) programme was developed to support participants in their recovery by (i) introducing education on the neuroscience underpinning persistent symptoms (with a particular focus on the autonomic nervous system) and (ii) the development of self-management strategies to support recovery. The aim of this study was to examine the feasibility of the TLC programme with a cohort of people significantly affected by LC.

Methods: Seventeen participants took part in the 8-week TLC programme which comprised of seven content sessions and one discussion (Q&A) session. Participants completed survey scales (investigating anxiety, pain-related interference, pain catastrophising, sleep disturbance and fatigue) at baseline, immediately post-programme (at 8 weeks), and retention (at 13 weeks). Participants also took part in focus group interviews to investigate their experiences of the programme.

Results: Fourteen participants (82%) attended at least six of the seven TLC content sessions. Decreases in mean values over time were observed across all measures, indicating a positive (non-significant) change. Participants reported an increase in understanding of LC, new hope for recovery, belief that they now had a realistic pathway for recovery, validation of their experiences and symptoms, meaningful improvements in function, and enhanced ability to respond to and attenuate physical symptoms. No adverse events were reported. Participants highlighted a number of programme strengths, along with some potential areas for improvement.

Conclusion: The TLC programme was shown to be feasible based on engagement, adherence, acceptable completion of surveys, and no adverse events. Study findings point to the potential for this programme to be refined, trialled and evaluated with a larger sample.

Patient or public contribution: Four people (living with LC, ME/CFS, chronic migraine and chronic Lyme, fibromyalgia, and centralised pain syndrome), who have experience of applying a recovery approach aligned with the TLC programme, acted in a PPI (Public and Patient Involvement in research) capacity on this study. In addition, the lead author has personal experience with the illness, and developing the recovery approach, which helped inform programme structure and development [1]. These individuals provided advice and guidance on the potential structure for the group programme, course duration, tool selection, and language and wording of the programme and materials. Further detail is provided in the Supplementary Materials.

Source: Belton S, Goss H, Whyte E, McCaffrey N, Gibney S, Sheridan K. ‘I Want Everyone to Have It, and Everyone to Be on It’: A Feasibility Study of the Transforming Long Covid Intervention. Health Expect. 2026 Jun;29(3):e70681. doi: 10.1111/hex.70681. PMID: 42076812. https://onlinelibrary.wiley.com/doi/10.1111/hex.70681 (Full text)

Post-Exertional Malaise in Post-COVID-19 Syndrome: A Shift in the Frequency Across Pandemic Phases

Abstract:

Background: Post-exertional malaise (PEM), which is the cardinal feature of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), is also reported in a proportion of patients with post-COVID-19 syndrome (PCS). Our objective was to identify determinants that may be linked to the emergence of PEM in PCS patients.

Methods: Patients fulfilling the World Health Organization definition for PCS who attended the post-COVID unit of the Internal Medicine Department of Angers University Hospital, France, between June 2020 and December 2023 were included retrospectively. Their medical records were reviewed to extract information on COVID-19 infection history, characteristics of post-exertional malaise (PEM), fatigue severity, and relevant epidemiological variables.

Results: The study included 220 patients, grouped according to whether post-exertional malaise was present (PCS/PEM+) or absent (PCS/PEM-). PEM was observed in 26.4% of patients and was significantly linked to earlier COVID onset in 2020/2021 (OR 5.68 (95% CI: 1.66-19.45), p = 0.006), as well as higher fatigue levels (OR 2.07 (95% CI: 1.22-3.50), p = 0.007).

Conclusions: Patients who contracted COVID-19 during the pre-Omicron period reported PEM more frequently than those infected in later waves. This observation could reflect differences in viral characteristics following the emergence of the Omicron variant; however, alternative explanations-such as increasing vaccination coverage, accumulating post-infectious immunity, or other unmeasured factors-cannot be ruled out. Based on the observed link between PEM and symptom severity, PCS patients should be systematically assessed for the presence of PEM.

Source: Ghali A, Lavigne C, Ghali M, Lacombe V. Post-Exertional Malaise in Post-COVID-19 Syndrome: A Shift in the Frequency Across Pandemic Phases. J Clin Med. 2026 Apr 13;15(8):2948. doi: 10.3390/jcm15082948. PMID: 42074751. https://www.mdpi.com/2077-0383/15/8/2948 (Full text)

Improving Diagnostic Accuracy of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Through a Point-of-Care Clinical Algorithm

Abstract:

Despite the increasing prevalence and median severity of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), medical education on the disease is scant, leading to a diagnostic crisis in which the majority of people with ME/CFS are undiagnosed. We created a care process algorithm in AskMayoExpert accessible to all Mayo Clinic medical providers as a source for information on diagnosis and management of ME/CFS.

To evaluate whether the algorithm was associated with improved diagnostic accuracy, we compared concordance before versus after the algorithm was introduced, where concordance was defined as agreement between an appropriately coded referral to Mayo Clinic’s Chronic Fatigue Specialty Clinic and the specialty clinic with an expert diagnosis of ME/CFS.

Referrals to the Chronic Fatigue Specialty Clinic increased overall and were more likely to show concordance between specialist diagnosis and referral after the introduction of the ME/CFS AskMayoExpert algorithm. Particularly in diseases that are prevalent and poorly understood, a point-of-care clinical tool may offer just-in-time opportunities to improve diagnosis and management.

Source: Seltzer J, Grach SL, Eggers SD, Redetzke MM, Mau KJ, Chon TY, Ganesh R. Improving Diagnostic Accuracy of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Through a Point-of-Care Clinical Algorithm. Int J Environ Res Public Health. 2026 Apr 3;23(4):460. doi: 10.3390/ijerph23040460. PMID: 42074399. https://www.mdpi.com/1660-4601/23/4/460 (Full text)

Digital Approaches for Managing Brain Fog in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Interventions, Monitoring, and Future Directions

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a high-burden, under-researched condition characterized by heterogeneous and fluctuating symptoms, including cognitive dysfunction commonly described by patients as “brain fog”. Despite growing interest in digital health technologies for symptom monitoring and personalized care, their application to the assessment and management of cognitive dysfunction in ME/CFS remains unclear. This descriptive review aimed to examine the current scientific evidence on digital approaches related to brain fog in ME/CFS.

A structured literature search following PRISMA guidance was conducted to identify relevant studies. The available literature remains limited in scope and methodological maturity. During synthesizing across studies, three main functional domains of digital application become apparent: (1) digital tools for cognitive assessment, which have the strongest evidence base; (2) digital platforms for longitudinal monitoring; and (3) digitally mediated interventions or rehabilitation approaches, both of which are less well studied.

Simultaneously, the findings suggest that patient-reported brain fog may represent a visible component of the broader ME/CFS disease spectrum and could serve as an early clinical indicator guiding diagnosis and management. Interpreting these symptoms within a biopsychosocial framework may facilitate understanding of the complex nature of the disease and optimize the use of digital technologies for monitoring cognitive dysfunction and supporting patient-centered care in ME/CFS.

Source: Araja D, Murovska M, Krumina A, Eory A, Berkis U. Digital Approaches for Managing Brain Fog in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Interventions, Monitoring, and Future Directions. Life (Basel). 2026 Apr 1;16(4):571. doi: 10.3390/life16040571. PMID: 42073381. https://www.mdpi.com/2075-1729/16/4/571 (Full text)