Tag: PEM

Awareness and Perception of Myalgic Encephalomyelitis and Chronic Fatigue Syndrome Among Pain Specialists: A Questionnaire-Based Study

Abstract:

Background: This study aims to explore the perceptions and clinical approaches of pain management specialists toward myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a condition characterized by persistent fatigue, widespread pain, unrefreshing sleep, and autonomic dysfunction. Given the challenges in diagnosis and management, pain specialists may play a pivotal role in symptom relief. By identifying variations in evaluation and treatment practices, this study seeks to enhance the recognition of ME/CFS and improve its clinical management within pain medicine.

Material and methods: The questionnaire was distributed in printed form to 250 pain specialists in Turkey. Given the limited number of pain physicians in the country, the study aimed to encompass all actively practicing specialists. The survey included four demographic questions, eight true-false questions, 12 multiple-choice questions, and four rating-scale questions. Data were collected anonymously. Data were analyzed using Statistical Product and Service Solutions (SPSS, version 27.0; IBM SPSS Statistics for Windows, Armonk, NY), with descriptive statistics and chi-square (χ²) tests applied to examine the relationships between awareness levels and attitudinal variables.

Results: In Turkey, 106 pain medicine physicians (42.4%) participated in the study. The average age was 40.6±8.52 years. Among the participants, 39.6% had previously heard of myalgic encephalomyelitis. Physicians were inclined to first ask the question, “Do you think you get enough sleep at night?” when evaluating these patients, with a rate of 63.2%. The majority of participants (65.9%) stated that they “occasionally” or “rarely” considered the relationship between fatigue and orthostatic intolerance. Additionally, 37.7% believed that this disease is a subtype of depression. The statement, “chronic fatigue decreases with intense aerobic exercise,” was agreed upon by 50.9% of participants. This controversial statement was particularly more common among those who were unaware of ME/CFS’s alternative name (p=0.009) and those who did not take dysautonomic disorders into account (p=0.048). When considering an ME/CFS diagnosis, physicians most frequently referred patients to the physical medicine and rehabilitation department (32.1%). Those who preferred not to refer patients to any department (12.3%) tended to find it appropriate for a patient to seek consultation at a pain medicine clinic due to widespread body pain and fatigue (χ2=11.405, p=0.044).

Conclusion: This study is the first questionnaire-based research assessing pain physicians’ awareness and attitudes toward ME/CFS. By highlighting their perspectives on its evaluation and management, our findings may improve recognition and clinical approaches to ME/CFS. Future research should focus on education and standardized guidelines to enhance patient care.

Source: Uygun GG, Gözükızıl ST, Bilen A. Awareness and Perception of Myalgic Encephalomyelitis and Chronic Fatigue Syndrome Among Pain Specialists: A Questionnaire-Based Study. Cureus. 2025 Mar 23;17(3):e81030. doi: 10.7759/cureus.81030. PMID: 40264626; PMCID: PMC12013460. https://pmc.ncbi.nlm.nih.gov/articles/PMC12013460/ (Full text)

How I treat my patients with Myalgic Encephalomyelitis, Chronic Fatigue Syndrome (ME/CVS), fibromyalgia or “long COVID”

Abstract:

Common to Myalgic encephalomyelitis, chronic fatigue syndrome and so-called long Covid is the panoply of complaints, with Post Exertional Malaise (PEM) as the most typical symptom. Added to that are permanent feeling of fatigue, decreased capacity to concentrate, so-called brain fog, non restorative sleep, diffuse pain, and – in case of long Covid – respiratory distress.

Several recent studies have confirmed my original hypothesis that poor metabolism and energy production by the mitochondria are responsible for the majority of these phenomena. I have suggested that inhibition of Pyruvate dehydrogenase (Pdh) activity is the major reason for this. Pdh inhibition is probably caused by the excess of the phosphatase: Pyruvate Dehydrogenase Kinase (PDK). The latter results from “Systemic Immune Disorder” (what I called “SID”) and inflammation.

Based on this hypothesis I have applied oral and infusion treatment modalities which were successful in approximately 80% of 130 consecutive patients. The pivotal substances are sodium dichloroacetate, that reduces PDK, Meldonium, that facilitates intracellular glucose metabolism, and low dose Nalexone, that optimises the function of microglia.

Source: Comhaire F. How I treat my patients with Myalgic Encephalomyelitis, Chronic Fatigue Syndrome (ME/CVS),
Fibromyalgia or “long COVID”. J Clin Images Med Case Rep. 2025; 6(3): 3508. https://jcimcr.org/pdfs/JCIMCR-v6-3508.pdf (Full text)

Wearable heart rate variability monitoring identifies autonomic dysfunction and thresholds for post-exertional malaise in Long COVID

Abstract:

Objectives Patients with Long COVID experience disabling fatigue, autonomic dysfunction, reduced exercise capacity, and post-exertional malaise (PEM). Heart rate variability (HRV) can evaluate autonomic function and monitor overexertion, potentially helping to mitigate PEM. This study aimed to use continuous multi-day HRV recordings to monitor overexertion and study autonomic function in Long COVID.

Method Heart rate and HRV were continuously measured in 127 patients with long COVID (43±11 years, 32% male) and 21 healthy controls (42±13 years, 48% male), and daily life activities tracked in a logbook. Participants underwent a (sub)maximal cardiopulmonary exercise test to determine heart rate at the first ventilatory threshold (VT1) to study HRV responses to exercise at different intensities.

Results HRV was lower in patients with long COVID compared to healthy controls during various daily activities and sleep (p<0.027). HRV remained lower for 24 hours after exercise below, at or above VT1 in patients, but not in healthy controls (p=0.010). Nighttime HRV decreased with intense exercise and longer durations in patients with long COVID (p=0.018), indicative of exercise-induced diurnal disturbances of the autonomic nervous system in long COVID.

Conclusion Heart rate variability, assessed by wearables, confirms autonomic dysfunction in patients with long COVID. The delayed recovery of the sympathovagal balance after exercise close and above to VT1 suggests that VT1 can be practically interpreted as a PEM threshold.

Application These results confirm the applicability of wearables to assess autonomic function and manage overexertion in long COVID patients.

What is already known on this topic Patients with long COVID often experience fatigue, autonomic dysfunction, and post-exertional malaise (PEM). HRV can be used as a non-invasive tool to measure autonomic function and recovery. Anecdotal evidence suggests lower HRV in patients with long COVID, but measurements are usually very short.

What this study adds This study demonstrates that continuous HRV monitoring through wearables can effectively identify overexertion and autonomic dysfunction during daily activities in patients with long COVID. Patients with long COVID have a lower heart rate variability during sleep and HRV remained significantly lower for a longer period after moderate-to-heavy exercise, that is generally associated with the induction of post-exertional malaise.

How this study might affect research, practice, or policy This study supports the use of wearables for assessing autonomic function and overexertion in daily life, helping patients with long COVID in pacing daily activities to mitigate symptoms of post-exertional malaise. HRV tracking after exercise shows that VT1 is a potential threshold for PEM. Sports physicians and physiotherapists can incorporate HRV biofeedback measures into pacing advice to patients. Additional research is needed to further investigate the effect of such an intervention.

Source: Twan Ruijgt, Anouk Slaghekke, Anneke Ellens, Kasper W. Janssen, Rob C.I. Wüst.. Wearable heart rate variability monitoring identifies autonomic dysfunction and thresholds for post-exertional malaise in Long COVID. medRxiv 2025.03.18.25320115; doi: https://doi.org/10.1101/2025.03.18.25320115 https://www.medrxiv.org/content/10.1101/2025.03.18.25320115v1.full-text (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; Behavior, 13(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)

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

Cerebrospinal fluid metabolomics, lipidomics and serine pathway dysfunction in myalgic encephalomyelitis/chronic fatigue syndroome (ME/CFS)

Abstract:

We proposed that cerebrospinal fluid would provide objective evidence for disrupted brain metabolism in myalgic encephalomyelitis/chronic fatigue syndroome (ME/CFS). The concept of postexertional malaise (PEM) with disabling symptom exacerbation after limited exertion that does not respond to rest is a diagnostic criterion for ME/CFS. We proposed that submaximal exercise provocation would cause additional metabolic perturbations.

The metabolomic and lipidomic constituents of cerebrospinal fluid from separate nonexercise and postexercise cohorts of ME/CFS and sedentary control subjects were contrasted using targeted mass spectrometry (Biocrates) and frequentist multivariate general linear regression analysis with diagnosis, exercise, gender, age and body mass index as independent variables. ME/CFS diagnosis was associated with elevated serine but reduced 5-methyltetrahydrofolate (5MTHF).

One carbon pathways were disrupted. Methylation of glycine led to elevated sarcosine but further methylation to dimethylglycine and choline was decreased. Creatine and purine intermediates were elevated. Transaconitate from the tricarboxylic acid cycle was elevated in ME/CFS along with essential aromatic amino acids, lysine, purine, pyrimidine and microbiome metabolites. Serine is a precursor of phospholipids and sphingomyelins that were also elevated in ME/CFS. Exercise led to consumption of lipids in ME/CFS and controls while metabolites were consumed in ME/CFS but generated in controls.

The findings differ from prior hypometabolic findings in ME/CFS plasma. The novel findings generate new hypotheses regarding serine-folate-glycine one carbon and serine-phospholipid metabolism, elevation of end products of catabolic pathways, shifts in folate, thiamine and other vitamins with exercise, and changes in sphingomyelins that may indicate myelin and white matter dysfunction in ME/CFS.

Source: Baraniuk JN. Cerebrospinal fluid metabolomics, lipidomics and serine pathway dysfunction in myalgic encephalomyelitis/chronic fatigue syndroome (ME/CFS). Sci Rep. 2025 Mar 3;15(1):7381. doi: 10.1038/s41598-025-91324-1. PMID: 40025157. https://www.nature.com/articles/s41598-025-91324-1 (Full text)

Serum Spike Protein Persistence Post COVID Is Not Associated with ME/CFS

Abstract:

Background/Objectives: According to the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC), an estimated 3-6% of people suffer from post-COVID condition or syndrome (PCS). A subset meets the diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Studies have reported that SARS-CoV-2 proteins or RNA can persist after acute infection in serum or tissues, but their role in PCS is unclear.

Methods: Here, SARS-CoV-2 spike protein was analyzed in the serum of 121 PCS patients with predominant fatigue and exertional intolerance, of whom 72 met diagnostic criteria for ME/CFS, 37 post-COVID recovered healthy controls, and 32 pre-pandemic healthy controls.

Results: Spike protein was detected in the serum of 11% of recovered controls, 2% of PCS patients, and 14% of ME/CFS patients between 4 and 31 months after SARS-CoV-2 infection, but not in pre-pandemic samples. The occurrence and concentration of spike protein did not correlate with infection or vaccination timepoints. In ME/CFS patients, spike protein presence was not associated with the severity of symptoms or functional disability. In 5 out of 22 patients who under-went immunoglobulin depletion, spike protein levels were reduced or undetectable after treatment, indicating binding to immunoglobulins.

Conclusions: In summary, this study identified serum spike protein in a subset of patients but found no association with ME/CFS.

Source: Fehrer A, Sotzny F, Kim L, Kedor C, Freitag H, Heindrich C, Grabowski P, Babel N, Scheibenbogen C, Wittke K. Serum Spike Protein Persistence Post COVID Is Not Associated with ME/CFS. J Clin Med. 2025 Feb 8;14(4):1086. doi: 10.3390/jcm14041086. PMID: 40004616. https://www.mdpi.com/2077-0383/14/4/1086 (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)

Exploring DNA methylation, telomere length, mitochondrial DNA, and immune function in patients with Long-COVID

Abstract:

Background: Long-COVID is defined as the persistency or development of new symptoms 3 months after the initial SARS-CoV-2 infection, with these symptoms lasting for at least 2 months with no other explanation. Common persistent symptoms are fatigue, sleep disturbances, post-exertional malaise (PEM), pain, and cognitive problems. Long-COVID is estimated to be present in about 65 million people. We aimed to explore clinical and biological factors that might contribute to Long-COVID.

Methods: Prospective longitudinal cohort study including patients infected with SARS-CoV-2 between March 2020 and March 2022. Patients were assessed between 4 and 12 months after infection at the COVID follow-up clinic at UZ Leuven. We performed a comprehensive clinical assessment (including questionnaires and the 6-min walking test) and biological measures (global DNA methylation, telomere length, mitochondrial DNA copy number, inflammatory cytokines, and serological markers such as C-reactive protein, D-dimer, troponin T).

Results: Of the 358 participants, 328 were hospitalised, of which 130 had severe symptoms requiring intensive care admission; 30 patients were ambulatory referrals. Based on their clinical presentation, we could identify 6 main clusters. One-hundred and twenty-seven patients (35.4%) belonged to at least one cluster. The bigger cluster included PEM, fatigue, sleep disturbances, and pain (n = 57). Troponin T and telomere shortening were the two main markers predicting Long-COVID and PEM-fatigue symptoms.

Conclusions: Long-COVID is not just one entity. Different clinical presentations can be identified. Cardiac involvement (as measured by troponin T levels) and telomere shortening might be a relevant risk factor for developing PEM-fatigue symptoms and deserve further exploring.

Source: Polli A, Godderis L, Martens DS, Patil MS, Hendrix J, Wyns A, Van Campenhout J, Richter E, Fanning L, Vandekerckhove O, Claeys E, Janssens W, Lorent N. Exploring DNA methylation, telomere length, mitochondrial DNA, and immune function in patients with Long-COVID. BMC Med. 2025 Feb 4;23(1):60. doi: 10.1186/s12916-025-03881-x. PMID: 39901177; PMCID: PMC11792217. https://pmc.ncbi.nlm.nih.gov/articles/PMC11792217/ (Full text)

Exertional Exhaustion (Post-Exertional Malaise, PEM) Evaluated by the Effects of Exercise on Cerebrospinal Fluid Metabolomics–Lipidomics and Serine Pathway in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract

Post-exertional malaise (PEM) is a defining condition of myalgic encephalomyelitis (ME/CFS). The concept requires that a provocation causes disabling limitation of cognitive and functional effort (“fatigue”) that does not respond to rest. Cerebrospinal fluid was examined as a proxy for brain metabolite and lipid flux and to provide objective evidence of pathophysiological dysfunction. Two cohorts of ME/CFS and sedentary control subjects had lumbar punctures at baseline (non-exercise) or after submaximal exercise (post-exercise). Cerebrospinal fluid metabolites and lipids were quantified by targeted Biocrates mass spectrometry methods.
Significant differences between ME/CFS and control, non-exercise vs. post-exercise, and by gender were examined by multivariate general linear regression and Bayesian regression methods. Differences were found at baseline between ME/CFS and control groups indicating disease-related pathologies, and between non-exercise and post-exercise groups implicating PEM-related pathologies.
A new, novel finding was elevated serine and its derivatives sarcosine and phospholipids with a decrease in 5-methyltetrahydrofolate (5MTHF), which suggests general dysfunction of folate and one-carbon metabolism in ME/CFS. Exercise led to consumption of lipids in ME/CFS and controls while metabolites were consumed in ME/CFS but generated in controls. In general, the frequentist and Bayesian analyses generated complementary but not identical sets of analytes that matched the metabolic modules and pathway analysis. Cerebrospinal fluid is unique because it samples the choroid plexus, brain interstitial fluid, and cells of the brain parenchyma.
The quantitative outcomes were placed into the context of the cell danger response hypothesis to explain shifts in serine and phospholipid synthesis; folate and one-carbon metabolism that affect sarcosine, creatine, purines, and thymidylate; aromatic and anaplerotic amino acids; glucose, TCA cycle, trans-aconitate, and coenzyme A in energy metabolism; and vitamin activities that may be altered by exertion. The metabolic and phospholipid profiles suggest the additional hypothesis that white matter dysfunction may contribute to the cognitive dysfunction in ME/CFS.
Source: Baraniuk JN. Exertional Exhaustion (Post-Exertional Malaise, PEM) Evaluated by the Effects of Exercise on Cerebrospinal Fluid Metabolomics–Lipidomics and Serine Pathway in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. International Journal of Molecular Sciences. 2025; 26(3):1282. https://doi.org/10.3390/ijms26031282 https://www.mdpi.com/1422-0067/26/3/1282 (Full text)