Category: Symptoms

Different risk factors distinguish myalgic encephalomyelitis/chronic fatigue syndrome from severe fatigue

Abstract:

Fatigue is a common reason that patients seek medical care. Only a fraction of these patients meet criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). To determine if ME/CFS is just a more extreme form of fatigue, or a qualitatively different condition, we assessed whether risk factors for ME/CFS and for Severe Fatigue were similar.

An email questionnaire that inquired about symptoms of Severe Fatigue and ME/CFS was completed by 41,802 US female nurses from whom detailed medical and lifestyle information had been collected since 1989: 102 met criteria for ME/CFS, 522 had Severe Fatigue, and 41,178 individuals were without significant chronic fatigue.

We used Cox proportional hazards regression to estimate the Hazard Ratio (HR) of Severe Fatigue and of ME/CFS with each of several potential risk factors, according to the level of exposure to each risk factor. The risk of Severe Fatigue was significantly increased among participants who were older, had a higher BMI in adulthood, used hormone therapy, had increased alcohol intake and decreased caffeine intake.

In contrast, these risk factor associations were not seen in people with ME/CFS. A self-reported past history of acute infectious mononucleosis was associated with a non-significantly increased Hazard Ratio of later ME/CFS (HR 1.77, 0.87–3.61) and, to a lesser extent, of Severe Fatigue (HR 1.28, 0.98–1.66). The different contribution of various risk factors to Severe Fatigue and ME/CFS suggests that ME/CFS has a qualitatively different underlying biology from the more common state of Severe Fatigue.

Source: Palacios, N., Molsberry, S., Fitzgerald, K.C. et al. Different risk factors distinguish myalgic encephalomyelitis/chronic fatigue syndrome from severe fatigue. Sci Rep 13, 2469 (2023). https://doi.org/10.1038/s41598-023-29329-x https://www.nature.com/articles/s41598-023-29329-x (Full text)

Symptom-based clusters in people with ME/CFS: an illustration of clinical variety in a cross-sectional cohort

Abstract:

Background: Myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) is a complex, heterogenous disease. It has been suggested that subgroups of people with ME/CFS exist, displaying a specific cluster of symptoms. Investigating symptom-based clusters may provide a better understanding of ME/CFS. Therefore, this study aimed to identify clusters in people with ME/CFS based on the frequency and severity of symptoms.

Methods: Members of the Dutch ME/CFS Foundation completed an online version of the DePaul Symptom Questionnaire version 2. Self-organizing maps (SOM) were used to generate symptom-based clusters using severity and frequency scores of the 79 measured symptoms. An extra dataset (n = 252) was used to assess the reproducibility of the symptom-based clusters.

Results: Data of 337 participants were analyzed (82% female; median (IQR) age: 55 (44–63) years). 45 clusters were identified, of which 13 clusters included ≥ 10 patients. Fatigue and PEM were reported across all of the symptom-based clusters, but the clusters were defined by a distinct pattern of symptom severity and frequency, as well as differences in clinical characteristics. 11% of the patients could not be classified into one of the 13 largest clusters. Applying the trained SOM to validation sample, resulted in a similar symptom pattern compared the Dutch dataset.

Conclusion: This study demonstrated that in ME/CFS there are subgroups of patients displaying a similar pattern of symptoms. These symptom-based clusters were confirmed in an independent ME/CFS sample. Classification of ME/CFS patients according to severity and symptom patterns might be useful to develop tailored treatment options.

Source: Vaes, A.W., Van Herck, M., Deng, Q. et al. Symptom-based clusters in people with ME/CFS: an illustration of clinical variety in a cross-sectional cohort. J Transl Med 21, 112 (2023). https://doi.org/10.1186/s12967-023-03946-6 https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03946-6 (Full text)

Orthostatic Intolerance and Chronotropic Incompetence in Patients With Myalgic Encephalomyelitis or Chronic Fatigue Syndrome

Abstract:

Background: Orthostatic intolerance markedly affects the day-to-day activities of patients with myalgic encephalomyelitis (ME) or chronic fatigue syndrome. Chronotropic incompetence (CI), defined as an impaired chronotropic response or reduced increases in heart rate during exercise and resulting in lower exercise capacity, may also be observed during orthostasis in patients with ME.

Methods and Results: In this study, the recordings of 101 adult patients with ME (36 men, 65 women; mean [±SD] age 37±12 years) who underwent conventional active 10-min standing tests at least 3 times to determine the presence of CI were analyzed. Recordings were selected for 13 patients who experienced tests both with and without exhibiting postural orthostatic tachycardia syndrome (POTS; an increase in heart rate of ≥30 beats/min or an actual heart rate of ≥120 beats/min) while also both successfully completing and failing to complete 10-min standing on different occasions. Subjects in whom failure without POTS was observed in any test(s) while success was associated with POTS on other occasions were considered positive for CI during orthostasis. Of the 13 patients, 12 (92%) were CI positive, 5 (38%) of whom exclusively failed the tests without experiencing POTS.

Conclusions: Some patients with ME were CI positive during standing tests, suggesting impaired sympathetic activation. The presence of POTS appears to be essential for maintaining orthostasis in these patients.

Source: Kunihisa Miwa. Orthostatic Intolerance and Chronotropic Incompetence in Patients With Myalgic Encephalomyelitis or Chronic Fatigue Syndrome. Circulation Reports, Article ID CR-22-0114. https://www.jstage.jst.go.jp/article/circrep/advpub/0/advpub_CR-22-0114/_html/-char/en (Full text)

Gastric dysmotility and gastrointestinal symptoms in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Background: Gastrointestinal symptoms are common in ME/CFS, but there is a knowledge gap in the literature concerning gastrointestinal motility features and detailed symptom description.

Objective: In this study, we aimed to characterize gastric motility and gastric symptoms in response to a liquid meal.

Methods: We included 20 patients with ME/CFS with abdominal complaints who were recruited to a double-blind randomized placebo-controlled trial of Rituximab. The patients of this sub study were examined with an ultrasound drink test, and gastrointestinal symptoms were evaluated using the Rome III questionnaire and Irritable Bowel Syndrome Symptom Severity Scale (IBS-SSS) questionnaire.

Results: We found that patients commonly reported fullness/bloating (75%), abdominal pain (45%) and nausea (35%). Ultrasound measurements revealed lower proximal measurements of the stomach after a meal (p < 0.01) and larger fasting antral area (p = 0.019) compared to healthy controls. The patients had a stronger symptomatic response to the liquid meal compared to healthy controls regarding epigastric pain, discomfort and nausea (p < 0.05). Ninety percent of the patients reported bowel movement frequencies within the normal range but scored high on bowel habit dissatisfaction and life disruption.

Conclusion: The patients presented with fullness/bloating, nausea and epigastric pain, showed signs of impaired gastric accommodation and visceral hypersensitivity, showing that the gastrointestinal symptoms of ME/CFS patients are similar to functional dyspepsia.

Key summary:

  • Gastrointestinal symptoms are common in ME/CFS, but there is a knowledge gap in the literature concerning gastrointestinal motility features and detailed symptom description.

  • In this study, patients with ME/CFS had signs of impaired gastric accommodation after a liquid meal.

  • Out of 20 patients, 15 patients reported fullness/bloating, 9 reported abdominal pain, and 7 reported nausea. The patients showed signs of visceral hypersensitivity on a drink test.

  • Our findings suggest that patients with ME/CFS share many similarities with patients with Functional Dyspepsia. The findings were not typical for Irritable Bowel Syndrome.

Source: Steinsvik EK, Hausken T, Fluge Ø, Mella O, Gilja OH. Gastric dysmotility and gastrointestinal symptoms in myalgic encephalomyelitis/chronic fatigue syndrome. Scand J Gastroenterol. 2023 Feb 2:1-8. doi: 10.1080/00365521.2023.2173533. Epub ahead of print. PMID: 36728717. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0280942 (Full text)

The Link Between Empty Sella Syndrome, Fibromyalgia, and Chronic Fatigue Syndrome: The Role of Increased Cerebrospinal Fluid Pressure

Abstract:

The etiopathogenesis of fibromyalgia (FM) and chronic fatigue syndrome (CFS) is not yet elucidated. Hypothalamo-pituitary-adrenal (HPA) axis dysfunction is reflected in the hormonal disturbances found in FM and CFS. Some study groups have introduced a novel hypothesis that moderate or intermittent intracranial hypertension may be involved in the etiopathogenesis of FM and CFS.

In these conditions, hormonal disturbances may be caused by the mechanical effect of increased cerebrospinal fluid pressure, which hampers blood flow in the pituitary gland. Severe intracranial pressure may compress the pituitary gland, resulting in primary empty sella (ES), potentially leading to pituitary hormone deficiencies.

The aim of this narrative review was to explore whether similar hormonal changes and symptoms exist between primary ES and FM or CFS and to link them to cerebrospinal fluid pressure dysregulation. A thorough search of the PubMed and Web of Science databases and the reference lists of the included studies revealed that several clinical characteristics were more prevalent in primary ES, FM or CFS patients than in controls, including increased cerebrospinal fluid pressure, obesity, female sex, headaches and migraine, fatigue, visual disturbances (visual acuity and eye motility abnormalities), vestibulocochlear disturbances (vertigo and neurosensorial hearing loss), and bodily pain (radicular pain and small-fiber neuropathy).

Furthermore, challenge tests of the pituitary gland showed similar abnormalities in all three conditions: blunted adrenocorticotropic hormone, cortisol, growth hormone, luteinizing hormone, and thyroid stimulating hormone responses and an increased prolactin response. The findings of this narrative review provide further support for the hypothesis that moderately or intermittently increased cerebrospinal fluid pressure is involved in the pathogenesis of FM and CFS and should stimulate further research into the etiopathogenesis of these conditions.

Source: Hulens M, Dankaerts W, Rasschaert R, Bruyninckx F, De Mulder P, Bervoets C. The Link Between Empty Sella Syndrome, Fibromyalgia, and Chronic Fatigue Syndrome: The Role of Increased Cerebrospinal Fluid Pressure. J Pain Res. 2023;16:205-219
https://doi.org/10.2147/JPR.S394321 https://www.dovepress.com/the-link-between-empty-sella-syndrome-fibromyalgia-and-chronic-fatigue-peer-reviewed-fulltext-article-JPR (Full text)

Converging Evidence of Similar Symptomatology of ME/CFS and PASC Indicating Multisystemic Dyshomeostasis

Abstract:

The purpose of this article is to review the evidence of similar symptomatology of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-acute sequelae of SARS-CoV-2 infection (PASC).
Reanalysis of data from a study by Jason comparing symptom reports from two groups of ME/CFS and PASC patients shows a notably similar symptomatology. Symptom scores of the PASC group and the ME/CFS group correlated 0.902 (p < 0.0001) across items. The hypothesis is presented that ME/CFS and PASC are caused by a chronic state of multisystemic disequilibrium including endocrinological, immunological, and/or metabolic changes.
The hypothesis holds that a changed set point persistently pushes the organism towards a pathological dysfunctional state which fails to reset. To use an analogy of a thermostat, if the ‘off switch’ of a thermostat intermittently stops working, for periods the house would become warmer and warmer without limit. The hypothesis draws on recent investigations of the Central Homeostasis Network showing multiple interconnections between the autonomic system, central nervous system, and brain stem.
The hypothesis helps to explain the shared symptomatology of ME/CFS and PASC and the unpredictable, intermittent, and fluctuating pattern of symptoms of ME/CFS and PASC. The current theoretical approach remains speculative and requires in-depth investigation before any definite conclusions can be drawn.
Source: Marks DF. Converging Evidence of Similar Symptomatology of ME/CFS and PASC Indicating Multisystemic Dyshomeostasis. Biomedicines. 2023; 11(1):180. https://doi.org/10.3390/biomedicines11010180 https://www.mdpi.com/2227-9059/11/1/180 (Full text)

A comparison of health-related factors between patients diagnosed with ME/CFS and patients with a related symptom picture but no ME/CFS diagnosis: a cross-sectional exploratory study

Abstract:

Background: In chronic fatigue syndrome/myalgic encephalomyelitis (ME/CFS), the capacity for activity and participation is strongly limited. The disease definition is very broad, and considering the lack of evidence for best treatment, it is important to understand what is ME/CFS-specific in the biopsychosocial perspective in comparison with similar syndromes. The objective was to study the difference between those diagnosed with ME/CFS and those with similar symptoms but no ME/CFS diagnosis for self-perceived level of physical activity, work ability, anxiety/depression, and health-related quality of life.

Methods: This was a clinical cross-sectional study with data collected from mailed questionnaires. The following variables were compared between patients diagnosed with ME/CFS (n = 205) and those with similar symptoms but no diagnosis (n = 57); level of physical activity, Work ability index (WAI), Hospital anxiety and depression scale (HAD-A/HAD-D), and RAND-36 Physical functioning, Role limitations due to physical health problems, Role limitations due to personal or emotional problems, Social functioning, Energy/fatigue, Bodily pain, Emotional well-being, and General health perceptions. The Chi-squared test (nominal data), the Mann-Whitney U test, the Student’s t test and regression analysis were used to analyze the data.

Results: The group diagnosed with ME/CFS had a more impaired physical and mental exertion ability as compared to the group that had similar symptoms but was not diagnosed with ME/CFS, shown by a RAND-36 lower index of physical role functioning, social functioning, energy, worse pain and poorer overall health (p ≤ 0.05). In contrast, no significant group differences emerged for weekly level of physical activity, work ability, anxiety/depression, and RAND-36 Emotional role limitation and well-being.

Conclusion: Our results indicate that those with a diagnosis of ME/CFS are characterized by an impaired ability for physical or mental exertion, worse pain, and poorer overall health as compared to individuals with similar symptoms but for whom ME/CFS-diagnosis was not established. The results may be cautiously interpreted as support when focusing on patients’ self-care in terms of management of energy levels. The results must however be verified in future studies.

Source: Bernhoff G, Rasmussen-Barr E, Bunketorp Käll L. A comparison of health-related factors between patients diagnosed with ME/CFS and patients with a related symptom picture but no ME/CFS diagnosis: a cross-sectional exploratory study. J Transl Med. 2022 Dec 9;20(1):577. doi: 10.1186/s12967-022-03769-x. PMID: 36494693; PMCID: PMC9733040. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03769-x (Full text)

Muscle sodium content in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Background: Muscle fatigue and pain are key symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Although the pathophysiology is not yet fully understood, there is ample evidence for hypoperfusion which may result in electrolyte imbalance and sodium overload in muscles. Therefore, the aim of this study was to assess levels of sodium content in muscles of patients with ME/CFS and to compare these to healthy controls.

Methods: Six female patients with ME/CFS and six age, BMI and sex matched controls underwent 23Na-MRI of the left lower leg using a clinical 3T MR scanner before and after 3 min of plantar flexion exercise. Sodium reference phantoms with solutions of 10, 20, 30 and 40 mmol/L NaCl were used for quantification. Muscle sodium content over 40 min was measured using a dedicated plugin in the open-source DICOM viewer Horos. Handgrip strength was measured and correlated with sodium content.

Results: Baseline tissue sodium content was higher in all 5 lower leg muscle compartments in ME/CFS compared to controls. Within the anterior extensor muscle compartment, the highest difference in baseline muscle sodium content between ME/CFS and controls was found (mean ± SD; 12.20 ± 1.66 mM in ME/CFS versus 9.38 ± 0.71 mM in controls, p = 0.0034). Directly after exercise, tissue sodium content increased in gastrocnemius and triceps surae muscles with + 30% in ME/CFS (p = 0.0005) and + 24% in controls (p = 0.0007) in the medial gastrocnemius muscle but not in the extensor muscles which were not exercised. Compared to baseline, the increase of sodium content in medial gastrocnemius muscle was stronger in ME/CFS than in controls with + 30% versus + 17% to baseline at 12 min (p = 0.0326) and + 29% versus + 16% to baseline at 15 min (p = 0.0265). Patients had reduced average handgrip strength which was associated with increased average muscle tissue sodium content (p = 0.0319, R2 = 0.3832).

Conclusion: Muscle sodium content before and after exercise was higher in ME/CFS than in healthy controls. Furthermore, our findings indicate an inverse correlation between muscle sodium content and handgrip strength. These findings provide evidence that sodium overload may play a role in the pathophysiology of ME/CFS and may allow for potential therapeutic targeting.

Source: Petter E, Scheibenbogen C, Linz P, Stehning C, Wirth K, Kuehne T, Kelm M. Muscle sodium content in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. J Transl Med. 2022 Dec 9;20(1):580. doi: 10.1186/s12967-022-03616-z. PMID: 36494667. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03616-z (Full text)

Differences in Symptoms among Black and White Patients with ME/CFS

Abstract:

Study samples of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) have primarily involved White subjects, so the literature on ethnic differences is sparse. The current study identified a sample of 19 Black patients diagnosed with ME/CFS and compared them with White patients with ME/CFS, as well as with healthy controls. The studies used a similar psychometrically sound assessment tool to assess symptoms in all subjects.

Findings indicated there were significant differences between patients with ME/CFS versus controls, but few differences between patients who identified as Black or White. The results suggest there might be few symptom differences between patients with ME/CFS in these two ethnic groups. The implications of these findings are discussed.

Source: Jason LA, Torres C. Differences in Symptoms among Black and White Patients with ME/CFS. J Clin Med. 2022 Nov 12;11(22):6708. doi: 10.3390/jcm11226708. PMID: 36431185. https://www.mdpi.com/2077-0383/11/22/6708 (Full text)

The autoimmune aetiology of unexplained chronic pain

Abstract:

Chronic pain is the leading cause of life years lived with disability worldwide. The aetiology of most chronic pain conditions has remained poorly understood and there is a dearth of effective therapies. The WHO ICD-11 has categorised unexplained chronic pain states as ‘chronic primary pains’ (CPP), which are further defined by their association with significant distress and/or dysfunction. The new mechanistic term, ‘nociplasticic pain’ has been developed to illustrate their presumed generation by a structurally intact, but abnormally functioning nociceptive system.

Recently, researchers have unravelled the surprising, ubiquitous presence of pain-sensitising autoantibodies in four investigated CPP indicating autoimmune causation. In persistent complex regional pain syndrome, fibromyalgia syndrome, chronic post-traumatic limb pain, and non-inflammatory joint pain associated with rheumatoid arthritis, passive transfer experiments have shown that either IgG or IgM antibodies from patient-donors cause symptoms upon injection to rodents that closely resemble those of the clinical disorders. Targets of antibody-binding and downstream effects vary between conditions, and more research is needed to elucidate the molecular and cellular details.

The central nervous system appears largely unaffected by antibody binding, suggesting that the clinically evident CNS symptoms associated with CPP might arise downstream of peripheral processes. In this narrative review pertinent findings are described, and it is suggested that additional symptom-based disorders might be examined for the contribution of antibody-mediated autoimmune mechanisms.

Source: Goebel A, Andersson D, Helyes Z, Clark JD, Dulake D, Svensson C. The autoimmune aetiology of unexplained chronic pain. Autoimmun Rev. 2022 Mar;21(3):103015. doi: 10.1016/j.autrev.2021.103015. Epub 2021 Dec 10. PMID: 34902604. https://www.sciencedirect.com/science/article/abs/pii/S1568997221002974 (Full text)