Identifying commonalities and differences between EHR representations of PASC and ME/CFS in the RECOVER EHR cohort

Abstract:

Background: Shared symptoms and biological abnormalities between post-acute sequelae of SARS-CoV-2 infection (PASC) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) could suggest common pathophysiological bases and would support coordinated treatment efforts. Empirical studies comparing these syndromes are needed to better understand their commonalities and differences.

Methods: We analyzed electronic health record data from 6.5 million adult patients from the National COVID Cohort Collaborative. PASC and ME/CFS diagnostic groups were defined based on recorded diagnoses, and other recorded conditions within the two groups were used to train separate machine learning-driven computable phenotypes (CPs). The most predictive conditions for each CP were examined and compared, and the overlap of patients labeled by each CP was examined. Condition records from the diagnostic groups were also used to statistically derive condition clusters. Rates of subphenotypes based on these clusters were compared between PASC and ME/CFS groups.

Results: Approximately half of patients labeled by one CP are also labeled by the other. Dyspnea, fatigue, and cognitive impairment are the most-predictive conditions shared by both CPs, whereas other most-predictive conditions are specific to one CP. Recorded conditions separate into cardiopulmonary, neurological, and comorbidity clusters, with the cardiopulmonary cluster showing partial specificity for the PASC groups.

Conclusions: Data-driven approaches indicate substantial overlap in the condition records associated with PASC and ME/CFS diagnoses. Nevertheless, cardiopulmonary conditions are somewhat more commonly associated with PASC diagnosis, whereas other conditions, such as pain and sleep disturbances, are more associated with ME/CFS diagnosis. These findings suggest that symptom management approaches to these illnesses could overlap.

Source: Powers JP, McIntee TJ, Bhatia A, Madlock-Brown CR, Seltzer J, Sekar A, Jain N, Hornig M, Seibert E, Leese PJ, Haendel M, Moffitt R, Pfaff ER; N3C Consortium and RECOVER-EHR. Identifying commonalities and differences between EHR representations of PASC and ME/CFS in the RECOVER EHR cohort. Commun Med (Lond). 2025 Apr 11;5(1):109. doi: 10.1038/s43856-025-00827-5. PMID: 40210986. https://www.nature.com/articles/s43856-025-00827-5 (Full text)

Physical function and psychosocial outcomes after a 6-month self-paced aquatic exercise program for individuals with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Purpose: A randomized-controlled trial to investigate the efficacy of a 6-month self-paced aquatic exercise intervention on physical function, symptoms and psychosocial measures in individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Methods: Thirty-two individuals diagnosed with ME/CFS (55.0 ± 13.9 yr) were randomized into an intervention group (INT, n = 17) or control group (CON, n = 15) for a 6-month trial of two 20-min sessions per week of self-paced aquatic movements and stretches. Pre- and post-intervention outcomes included physiological measures, 6-min walk test, hand-grip strength, Sit-to-Stand, Apley’s shoulder test, Sit-Reach test, perceived exertion, fatigue (FACIT), anxiety/depression (HADS) questionnaires, and tiredness and pain scores (VAS 0-10 scale).

Results: The INT group significantly increased walk test distance (13.7%, P < 0.001), Sit-to-Stand scores (33.7%, P < 0.001) and peak expiratory pulmonary flow (12.9%, P = 0.028) post-intervention. Fatigue (29.5%, P = 0.005), depression (21.7%, P = 0.010), combined anxiety/depression scores (16.9%, P = 0.047) and resting diastolic blood pressure (4.8%, P < 0.001) also significantly improved for the INT group. Sit-Reach scores were significantly lower for the INT group compared to CON post-intervention (- 4.0 ± 10.4 vs + 4.3 ± 10.7 cm, P = 0.034). There were no adverse events or worsening of symptoms during the trial.

Conclusions: Self-paced, low-moderate-intensity aquatic exercise improved walk distance, lower limb strength, fatigue, depression and peak expiratory flow without worsening ME/CFS symptoms. This mode of low-intensity physical activity may confer mental health and physical benefits provided the activity is self-paced and within patient energy limits.

Source: Broadbent S, Coetzee S, Calder A, Beavers R. Physical function and psychosocial outcomes after a 6-month self-paced aquatic exercise program for individuals with myalgic encephalomyelitis/chronic fatigue syndrome. Eur J Appl Physiol. 2025 Apr 5. doi: 10.1007/s00421-025-05759-5. Epub ahead of print. PMID: 40186656. https://link.springer.com/article/10.1007/s00421-025-05759-5 (Full text)

Stellate Ganglion Block reduces symptoms of SARS-CoV-2-induced ME/CFS: A prospective cohort pilot study

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating condition characterized by fatigue, orthostatic intolerance (OI), post-exertional malaise (PEM) and unrefreshing sleep. Our previous work has shown that modulating the autonomic nervous system can alleviate symptoms of Long COVID, which shares striking similarities with ME/CFS.

Objective: Determine the effect of stellate ganglion block (SGB) on symptoms of ME/CFS.

Methods: Subjects who met the WHO criteria for Long COVID and the Institute of Medicine criteria for ME/CFS were treated with sequential bilateral SGBs separated by 18–24 hours for three consecutive weeks (n = 10). At baseline, and at 2-weeks and 2-months post-treatment, we collected subjective assessments (SF-36 and DSQ2) of symptoms, objective assessments of orthostatic intolerance and cognitive performance, and saliva to measure morning cortisol. During the entire study period, a wearable device collected physiological data several nights a week to measure sleep parameters.

Results: DSQ2 measures of PEM, Unrefreshing Sleep, Cognitive Impairment, and OI improved significantly following treatment. SF-36 measures of Vitality, Physical Function, and Social Function improved significantly following treatment. Objective symptoms of POTS associated with infectious onset resolved following treatment. Objective measures of cognitive impairment were reduced following treatment, most notably in the areas of Immediate and Delayed Recognition. Morning cortisol and measures of sleep architecture did not change significantly following treatment.

Conclusions: Symptoms of ME/CFS were reduced after treatment with SGBs in this small prospective cohort pilot study. Given the lack of FDA-approved treatments for ME/CFS, replication of results in a large clinical trial is warranted.

Source: Duricka, D. L., & Liu, L. D. (2025). Stellate Ganglion Block reduces symptoms of SARS-CoV-2-induced ME/CFS: A prospective cohort pilot study. Fatigue: Biomedicine, Health &amp; Behavior13(2), 97–114. https://doi.org/10.1080/21641846.2025.2455876 https://www.tandfonline.com/doi/full/10.1080/21641846.2025.2455876#d1e276 (Full text)

Understanding symptom clusters, diagnosis and healthcare experiences in myalgic encephalomyelitis/chronic fatigue syndrome and long COVID: a cross-sectional survey in the UK

Abstract:

Objectives: This study aims to provide an in-depth analysis of the symptoms, coexisting conditions and service utilisation among people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and long COVID. The major research questions include the clustering of symptoms, the relationship between key factors and diagnosis time, and the perceived impact of National Institute for Health and Care Excellence (NICE) guidelines on patient care.

Design: Cross-sectional survey using secondary data analysis.

Setting: Community-based primary care level across the UK, incorporating online survey participation.

Participants: A total of 10 458 individuals responded to the survey, of which 8804 confirmed that they or a close friend/family member had ME/CFS or long COVID. The majority of respondents were female (83.4%), with participants from diverse regions of the UK.

Primary and secondary outcome measures: Primary outcomes included prevalence and clustering of symptoms, time to diagnosis, and participant satisfaction with National Health Service (NHS) care, while secondary outcomes focused on symptom management strategies and the perceived effect of NICE guidelines.

Results: Fatigue (88.2%), postexertional malaise (78.2%), cognitive dysfunction (88.4%), pain (87.6%) and sleep disturbances (88.2%) were the most commonly reported symptoms among participants with ME/CFS, with similar patterns observed in long COVID. Time to diagnosis for ME/CFS ranged widely, with 22.1% diagnosed within 1-2 years of symptom onset and 12.9% taking more than 10 years. Despite updated NICE guidelines, only 10.1% of participants reported a positive impact on care, and satisfaction with NHS services remained low (6.9% for ME/CFS and 14.4% for long COVID).

Conclusions: ME/CFS and long COVID share overlapping but distinct symptom clusters, indicating common challenges in management. The findings highlight significant delays in diagnosis and low satisfaction with specialist services, suggesting a need for improved self-management resources and better-coordinated care across the NHS.

Source: Mansoubi M, Richards T, Ainsworth-Wells M, Fleming R, Leveridge P, Shepherd C, Dawes H. Understanding symptom clusters, diagnosis and healthcare experiences in myalgic encephalomyelitis/chronic fatigue syndrome and long COVID: a cross-sectional survey in the UK. BMJ Open. 2025 Apr 2;15(4):e094658. doi: 10.1136/bmjopen-2024-094658. PMID: 40180399. https://bmjopen.bmj.com/content/15/4/e094658 (Full text)

Recognizing the role of fibromyalgia in post-exertional malaise

Letter:

The recent opinion by Charlton et al. published in Trends in Endocrinology & Metabolism [] provides a thought-provoking discussion of the overlap between long coronavirus disease (long-COVID) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), emphasizing the centrality of post-exertional malaise (PEM) as a shared mechanism.

Here, we suggest that fibromyalgia should be included in the discussion, given the established role of PEM in this condition []. In addition, fibromyalgia not only shares symptomatic and mechanistic overlaps with ME/CFS, but also offers a complementary perspective on the pathophysiology of PEM. Considering that PEM is a key symptom in both fibromyalgia and long COVID, exploring skeletal muscle function in fibromyalgia could provide complementary insights into the muscle-specific alterations that contribute to this debilitating phenomenon.

Source: Giollo A, Salvato M, Doria A. Recognizing the role of fibromyalgia in post-exertional malaise. Trends Endocrinol Metab. 2025 Mar 11:S1043-2760(25)00045-1. doi: 10.1016/j.tem.2025.02.005. Epub ahead of print. PMID: 40074568. https://www.cell.com/trends/endocrinology-metabolism/abstract/S1043-2760(25)00045-1

Cerebral Blood Flow in Orthostatic Intolerance

Abstract:

Cerebral blood flow (CBF) is vital for delivering oxygen and nutrients to the brain. Many forms of orthostatic intolerance (OI) involve impaired regulation of CBF in the upright posture, which results in disabling symptoms that decrease quality of life. Because CBF is not easy to measure, rises in heart rate or drops in blood pressure are used as proxies for abnormal CBF. These result in diagnoses such as postural orthostatic tachycardia syndrome and orthostatic hypotension. However, in many other OI syndromes such as myalgic encephalomyelitis/chronic fatigue syndrome and long COVID, heart rate and blood pressure are frequently normal despite significant drops in CBF. This often leads to the incorrect conclusion that there is nothing hemodynamically abnormal in these patients and thus no explanation or treatment is needed. There is a need to measure CBF, as orthostatic hypoperfusion is the shared pathophysiology for all forms of OI. In this review, we examine the literature studying CBF dysfunction in various syndromes with OI and evaluate methods of measuring CBF including transcranial Doppler ultrasound, extracranial cerebral blood flow ultrasound, near infrared spectroscopy, and wearable devices.

Source: Khan MS, Miller AJ, Ejaz A, Molinger J, Goyal P, MacLeod DB, Swavely A, Wilson E, Pergola M, Tandri H, Mills CF, Raj SR, Fudim M. Cerebral Blood Flow in Orthostatic Intolerance. J Am Heart Assoc. 2025 Feb 3:e036752. doi: 10.1161/JAHA.124.036752. Epub ahead of print. PMID: 39895557. https://www.ahajournals.org/doi/10.1161/JAHA.124.036752 (Full text)

Digital health app data reveals an effect of ovarian hormones on long COVID and myalgic encephalomyelitis symptoms

Abstract:

Background. Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) disproportionately affect females, suggesting modulation by sex hormones. We sought to investigate whether symptom severity is influenced by changes in sex hormones over the menstrual cycle, or by hormonal contraception.

Methods: We carried out a retrospective analysis of menstrual and symptom data, prospectively collected via the Visible app from individuals with long COVID, ME/CFS, or both, who had regular menstrual cycles, between 7 September 2022 and 6 March 2024. Mixed-effects models were used to examine associations between symptom severity, menstrual cycle phase and contraception type.

Findings: 948 users were included; 100% of users were female and 92.6% identified as women. The most tracked symptoms were fatigue (99.5% of users), brain fog (88.3%), headaches (85.1%) and muscle aches (78.6%). All menstrual cycle phases showed a modest, but significant, improvement compare to the menstrual phase, most markedly in the early luteal (IRR 0.963%, 95% CI: 0.958 – 0.968), but also the follicular (IRR = 0.985, 95% CI: 0.981 – 0.990) and late luteal phase (IRR = 0.980, 95% CI: 0.974-0.985). Crashes (sudden and severe worsening of symptoms following exertion) were significantly more frequent during menstruation than in other phases. Users of combined hormonal contraception (n=70) had a statistically significant reduction in overall symptom score (OR = 0.827, 95% CI: 0.690 – 0.992) and crash incidence (OR = 0.548, 95% CI: 0.350 – 0.856) compared to those not using hormonal contraception (=786).

Interpretation: Menstruation is associated with worsened symptoms in long COVID and ME/CFS. Users of combined hormonal contraception report a lower symptom burden than non-users, suggesting a modulatory role of ovarian hormones. These findings could empower menstruating people living with long COVID and ME/CFS to anticipate cyclical changes in symptoms and plan their activities accordingly, and could also inform their use of contraception.

Source: Abigail Goodship, Rory Preston, Joseph T Hicks, Harry Leeming, Christian Morgenstern, Victoria Male. Digital health app data reveals an effect of ovarian hormones on long COVID and myalgic encephalomyelitis symptoms. medRxiv 2025.01.24.25321092; doi: https://doi.org/10.1101/2025.01.24.25321092 https://www.medrxiv.org/content/10.1101/2025.01.24.25321092v1 (Full text available as PDF file)

Tetrahydrobiopterin in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Friend or Foe?

Abstract:

Myalgic Encephalomyelitis or Chronic Fatigue Syndrome (ME/CFS) is a chronic multisystem disease characterized by severe muscle fatigue, pain, dizziness, and brain fog. The two most common symptoms are post-exertional malaise (PEM) and orthostatic intolerance (OI). ME/CFS patients with OI (ME+OI) suffer from dizziness or faintness due to a sudden drop in blood pressure while maintaining an upright posture. Clinical research has demonstrated that patients with OI display severe cardiovascular abnormalities resulting in reduced effective blood flow in the cerebral blood vessels. However, despite intense investigation, it is not known why the effective cerebral blood flow is reduced in OI patients. Based on our recent findings, we observed that tetrahydrobiopterin (BH4) metabolism was highly dysregulated in ME+OI patients. In the current review article, we attempted to summarize our recent findings on BH4 metabolism to shed light on the molecular mechanisms of OI.

Source: Rahman AFMT, Benko A, Bulbule S, Gottschalk CG, Arnold LA, Roy A. Tetrahydrobiopterin in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Friend or Foe? Biomolecules. 2025 Jan 10;15(1):102. doi: 10.3390/biom15010102. PMID: 39858496; PMCID: PMC11763651. https://pmc.ncbi.nlm.nih.gov/articles/PMC11763651/ (Full text)

Provocation of brachial plexus and systemic symptoms during the elevated arm stress test in individuals with myalgic encephalomyelitis/chronic fatigue syndrome or idiopathic chronic fatigue

Abstract:

Background: We have noted that some adolescents and young adults with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) report difficulty with arms-overhead activities, suggestive of brachial plexus dysfunction or thoracic outlet syndrome (TOS). In the TOS literature, diagnostic maneuvers focus on the provocation of upper limb symptoms (arm fatigue and heaviness, paresthesias, neck and upper back pain), but not on elicitation of systemic symptoms.

Objectives: To estimate the proportion of patients with fatiguing illness who experience local and systemic symptoms during a common maneuver used in evaluating TOS-the elevated arm stress test (EAST).

Methods: Patients were eligible for this retrospective study if they had been referred to the Johns Hopkins Chronic Fatigue Clinic between January 2020 and July 2023 and (a) reported difficulty maintaining arms-overhead postures, (b) were evaluated with an abbreviated one-minute EAST, and (c) had not undergone surgery in the upper limb, neck, or skull base. Modified EAST procedure: patients sat with their arms in a “hands up” or “candlestick” position while opening and closing their hands every 2-3 s repeatedly for 1 min, rather than the customary 3 min. The test was considered abnormal for local symptoms if the participant experienced pain, fatigue, heaviness, paresthesias, warmth or tremulousness in the upper limb, shoulder, neck, head, or upper back. The test was considered abnormal for systemic symptoms if the participant experienced overall fatigue, cognitive fogginess, lightheadedness, racing heart, diaphoresis, dyspnea, overall warmth, or nausea.

Results: Of 154 patients evaluated during the study period, 64 (42%) met the eligibility criteria (61/64 female, median age 18 years [range, 13 to 50]). Of the 64, 50 (78%) had ME/CFS, 13 (20%) had idiopathic chronic fatigue with associated orthostatic intolerance (OI), and one had idiopathic chronic fatigue without OI. Of the 64, 58% had evidence of joint hypermobility. Local symptoms were provoked by EAST in 62/64 (97%) within a median of 20 s. During EAST, 26/64 (41%) reported systemic symptoms (1 had only systemic but no upper limb symptoms), most commonly lightheadedness (19%) and generalized fatigue (11%).

Conclusions: Even with an abbreviated test duration, the EAST maneuver provoked local and systemic symptoms in a substantial proportion of patients with chronic fatigue, OI, and ME/CFS who had reported difficulty with arms-overhead postures. Further studies are needed to explore the prevalence of brachial plexus or TOS symptoms in unselected individuals with ME/CFS or OI, and the proportion with systemic symptoms during and after EAST.

Source: Edwards CC 3rd, Byrnes JM, Broussard CA, Azola AM, Swope ME, Marden CL, Swope RL, Lum YW, Violand RL, Rowe PC. Provocation of brachial plexus and systemic symptoms during the elevated arm stress test in individuals with myalgic encephalomyelitis/chronic fatigue syndrome or idiopathic chronic fatigue. J Transl Med. 2025 Jan 22;23(1):106. doi: 10.1186/s12967-025-06137-7. PMID: 39844172; PMCID: PMC11752803. https://pmc.ncbi.nlm.nih.gov/articles/PMC11752803/ (Full text)

Hippocampal subfield volume alterations and associations with severity measures in long COVID and ME/CFS: A 7T MRI study

Abstract:

Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) patients share similar symptoms including post-exertional malaise, neurocognitive impairment, and memory loss. The neurocognitive impairment in both conditions might be linked to alterations in the hippocampal subfields. Therefore, this study compared alterations in hippocampal subfields of 17 long COVID, 29 ME/CFS patients, and 15 healthy controls (HC).

Structural MRI data was acquired with sub-millimeter isotropic resolution on a 7 Telsa MRI scanner and hippocampal subfield volumes were then estimated for each participant using FreeSurfer software. Our study found significantly larger volumes in the left hippocampal subfields of both long COVID and ME/CFS patients compared to HC.

These included the left subiculum head (long COVID; p = 0.01, ME/CFS; p = 0.002,), presubiculum head (long COVID; p = 0.004, ME/CFS; p = 0.005), molecular layer hippocampus head (long COVID; p = 0.014, ME/CFS; p = 0.011), and whole hippocampal head (long COVID; p = 0.01, ME/CFS; p = 0.01). Notably, hippocampal subfield volumes were similar between long COVID and ME/CFS patients.

Additionally, we found significant associations between hippocampal subfield volumes and severity measures of ‘Pain’, ‘Duration of illness’, ‘Severity of fatigue’, ‘Impaired concentration’, ‘Unrefreshing sleep’, and ‘Physical function’ in both conditions. These findings suggest that hippocampal alterations may contribute to the neurocognitive impairment experienced by long COVID and ME/CFS patients. Furthermore, our study highlights similarities between these two conditions.

Source: Thapaliya K, Marshall-Gradisnik S, Eaton-Fitch N, Barth M, Inderyas M, Barnden L. Hippocampal subfield volume alterations and associations with severity measures in long COVID and ME/CFS: A 7T MRI study. PLoS One. 2025 Jan 13;20(1):e0316625. doi: 10.1371/journal.pone.0316625. PMID: 39804864; PMCID: PMC11729965. https://pmc.ncbi.nlm.nih.gov/articles/PMC11729965/ (Full text)