Warning Signals of Post-Exertional Malaise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Retrospective Analysis of 197 Patients

Abstract:

Post-exertional malaise (PEM), the key feature of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), is characterized by baseline symptom exacerbation after exposure to a stressor, and some patients can experience new or non-typical symptoms. We hypothesized that new or non-typical symptoms occurring long enough before onset of baseline symptom exacerbation could be warning signals predicting PEM.

Adult ME/CFS patients who attended the internal medicine department of Angers University Hospital (France) between October 2011 and December 2019 were included in a retrospective medical records review. Patients who experienced one or more new or non-typical symptoms before baseline symptom exacerbation were compared with the rest of the study population for PEM features, epidemiological characteristics, fatigue features, and comorbidities. New or non-typical symptoms preceded baseline symptom exacerbation in 27/197 (13.7%) patients, and the most frequent ones were mood disorders (37%). When compared to the rest of the study population, only PEM intensity was significantly lower in these patients (p = 0.004), even after adjustment for sex and age at disease onset (p = 0.007).

New or non-typical symptoms preceding baseline symptom exacerbation in some ME/CFS patients could be warning signals for PEM. Their identification could help preventing PEM occurrences or reducing their intensity leading to improving disease prognosis.

Source: Ghali A, Lacout C, Ghali M, Gury A, Delattre E, Lavigne C, Urbanski G. Warning Signals of Post-Exertional Malaise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Retrospective Analysis of 197 Patients. J Clin Med. 2021 Jun 7;10(11):2517. doi: 10.3390/jcm10112517. PMID: 34200126. https://pubmed.ncbi.nlm.nih.gov/34200126/

Comparing Idiopathic Chronic Fatigue and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) in Males: Response to Two-Day Cardiopulmonary Exercise Testing Protocol

Abstract:

(1) Introduction: Multiple studies have shown that peak oxygen consumption is reduced in the majority of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS )patients, using the gold standard for measuring exercise intolerance: cardiopulmonary exercise testing (CPET). A 2-day CPET protocol has shown different results on day 2 in ME/CFS patients compared to sedentary controls. No comparison is known between ME/CFS and idiopathic chronic fatigue (ICF) for 2-day CPET protocols. We compared ME/CFS patients with patients with chronic fatigue who did not fulfill the ME/CFS criteria in a male population and hypothesized a different pattern of response would be present during the 2nd day CPET.

(2) Methods: We compared 25 male patients with ICF who had completed a 2-day CPET protocol to an age-/gender-matched group of 26 male ME/CFS patients. Measures of oxygen consumption (VO2), heart rate (HR), systolic and diastolic blood pressure, workload (Work), and respiratory exchange ratio (RER) were collected at maximal (peak) and ventilatory threshold (VT) intensities.

(3) Results: Baseline characteristics for both groups were similar for age, body mass index (BMI), body surface area, (BSA), and disease duration. A significant difference was present in the number of patients with fibromyalgia (seven ME/CFS patients vs. zero ICF patients). Heart rate at rest and the RER did not differ significantly between CPET 1 and CPET 2. All other CPET parameters at the ventilatory threshold and maximum exercise differed significantly (p-value between 0.002 and <0.0001). ME/CFS patients showed a deterioration of performance on CPET2 as reflected by VO2 and workload at peak exercise and ventilatory threshold, whereas ICF patients showed improved performance on CPET2 with no significant change in peak workload.

(4) Conclusion: This study confirms that male ME/CFS patients have a reduction in exercise capacity in response to a second-day CPET. These results are similar to published results in male ME/CFS populations. Patients diagnosed with ICF show a different response on day 2, more similar to sedentary and healthy controls.

Source: van Campen CLMC, Visser FC. Comparing Idiopathic Chronic Fatigue and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) in Males: Response to Two-Day Cardiopulmonary Exercise Testing Protocol. Healthcare (Basel). 2021 Jun 5;9(6):683. doi: 10.3390/healthcare9060683. PMID: 34198946. https://pubmed.ncbi.nlm.nih.gov/34198946/

Female Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome or Idiopathic Chronic Fatigue: Comparison of Responses to a Two-Day Cardiopulmonary Exercise Testing Protocol

Abstract:

Introduction: Multiple studies have shown that peak oxygen consumption is reduced in the majority of ME/CFS patients, using the golden standard for measuring exercise intolerance: cardiopulmonary exercise testing (CPET). A 2-day CPET protocol has shown different results on day 2 in ME/CFS patients compared to sedentary controls. No comparison is known between ME/CFS and idiopathic chronic fatigue (ICF) for 2-day CPET protocols. We compared ME/CFS patients with patients with chronic fatigue who did not fulfil the ME/CFS criteria in a male population and hypothesized a different pattern of response would be present during the 2nd day CPET.

Methods: Fifty-one female patients with ICF completed a 2-day CPET protocol and were compared to an age/sex-matched group of 50 female ME/CFS patients. Measures of oxygen consumption (VO2), heart rate (HR), systolic and diastolic blood pressure, workload (Work), and respiratory exchange ratio (RER) were collected at maximal (peak) and ventilatory threshold (VT) intensities.

Results: Baseline characteristics for both groups were similar for age, BMI, BSA, and disease duration. A significance difference was present in the number of patients with fibromyalgia (seven ME/CFS patients vs zero ICF patients). Heart rate at rest and the RER did not differ significantly between CPET 1 and CPET 2. All other CPET parameters at the ventilatory threshold and maximum exercise differed significantly (p-value between 0.002 and <0.0001). ME/CFS patients showed a deterioration of performance on CPET2 as reflected by VO2 and workload at peak exercise and ventilatory threshold, whereas ICF patients showed improved performance on CPET2 with no significant change in peak workload.

Conclusion: This study confirms that female ME/CFS patients have a reduction in exercise capacity in response to a second day CPET. These results are similar to published results in female ME/CFS populations. Patients diagnosed with ICF show a different response on day 2, more similar to sedentary and healthy controls.

Source: van Campen CLMC, Visser FC. Female Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome or Idiopathic Chronic Fatigue: Comparison of Responses to a Two-Day Cardiopulmonary Exercise Testing Protocol. Healthcare (Basel). 2021 Jun 5;9(6):682. doi: 10.3390/healthcare9060682. PMID: 34198913. https://pubmed.ncbi.nlm.nih.gov/34198913/

Post-Acute COVID-19 Syndrome and the cardiovascular system: What is known?

Abstract:

Post-Acute COVID-19 Syndrome (PACS) is defined by persistent symptoms >3-4 weeks after onset of COVID-19. The mechanism of these persistent symptoms is distinct from acute COVID-19 although not completely understood despite the high incidence of PACS. Cardiovascular symptoms such as chest pain and palpitations commonly occur in PACS, but the underlying cause of symptoms is infrequently known. While autopsy studies have shown that the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) rarely causes direct myocardial injury, several syndromes such as myocarditis, pericarditis, and Postural Orthostatic Tachycardia Syndrome have been implicated in PACS. Additionally, patients hospitalized with acute COVID-19 who display biomarker evidence of myocardial injury may have underlying coronary artery disease revealed by the physiological stress of SARS-CoV-2 infection and may benefit from medical optimization. We review what is known about PACS and the cardiovascular system and propose a framework for evaluation and management of related symptoms.

Source: Dixit NM, Churchill A, Nsair A, Hsu JJ. Post-Acute COVID-19 Syndrome and the cardiovascular system: What is known? Am Heart J Plus. 2021 May;5:100025. doi: 10.1016/j.ahjo.2021.100025. Epub 2021 Jun 24. PMID: 34192289; PMCID: PMC8223036. https://pubmed.ncbi.nlm.nih.gov/34192289/

Parent-child discrepancies in health-related quality of life of children and adolescents with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Purpose: Few studies have examined parent-child discrepancies on self-report measures of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) symptomatology and health-related quality of life (HRQOL). The aim of this study was to investigate parent-child reporting discrepancies between a pediatric sample of diagnosed patients with ME/CFS and controls to better understand the role of children and adolescent reporting.

Method: Data for this study were drawn from a community-based epidemiological study of pediatric ME/CFS in the Chicagoland area. A total of 147 parent-child dyads (75 pairs with ME/CFS and 72 control pairs) completed measures assessing HRQOL and ME/CFS symptomatology. At the individual level, agreement was assessed using intra-class correlation coefficient (ICC) scores. Agreement was measured at the group level by a comparison of means using paired-sample t-tests.

Results: Intra-class correlations revealed varied agreement in both parent-child pairs of children who met at least one case definition of ME/CFS and in parent-child pairs in the control group.

Conclusion: The current study provides support for the existence of discrepancies between parent-child reports of ME/CFS symptomatology and HRQOL measures. Limitations and future directions are discussed.

Source: Ekberg KM, Torres C, Jason LA. Parent-child discrepancies in health-related quality of life of children and adolescents with myalgic encephalomyelitis/chronic fatigue syndrome. Qual Life Res. 2021 Jun 30. doi: 10.1007/s11136-021-02919-w. Epub ahead of print. PMID: 34191221. https://pubmed.ncbi.nlm.nih.gov/34191221/

Passive transfer of fibromyalgia symptoms from patients to mice

Abstract:

Fibromyalgia syndrome (FMS) is characterized by widespread pain and tenderness, and patients typically experience fatigue and emotional distress. The etiology and pathophysiology of fibromyalgia are not fully explained and there are no effective drug treatments. Here we show that IgG from FMS patients produced sensory hypersensitivity by sensitizing nociceptive neurons. Mice treated with IgG from FMS patients displayed increased sensitivity to noxious mechanical and cold stimulation, and nociceptive fibers in skin-nerve preparations from mice treated with FMS IgG displayed an increased responsiveness to cold and mechanical stimulation.

These mice also displayed reduced locomotor activity, reduced paw grip strength, and a loss of intraepidermal innervation. In contrast, transfer of IgG-depleted serum from FMS patients or IgG from healthy control subjects had no effect. Patient IgG did not activate naive sensory neurons directly. IgG from FMS patients labeled satellite glial cells and neurons in vivo and in vitro, as well as myelinated fiber tracts and a small number of macrophages and endothelial cells in mouse dorsal root ganglia (DRG), but no cells in the spinal cord. Furthermore, FMS IgG bound to human DRG. Our results demonstrate that IgG from FMS patients produces painful sensory hypersensitivities by sensitizing peripheral nociceptive afferents and suggest that therapies reducing patient IgG titers may be effective for fibromyalgia.

Source: Andreas Goebel, … , Camilla I. Svensson, David A. Andersson. Passive transfer of fibromyalgia symptoms from patients to mice. J Clin Invest. 2021;131(13):e144201. https://doi.org/10.1172/JCI144201. Published July 1, 2021 https://www.jci.org/articles/view/144201?key=51bf6d85e305f6b62f87 (Full text)

An app to help assess the severity of symptoms in chronic fatigue syndrome

Press release Eurekalert:

Chronic fatigue syndrome / myalgic encephalomyelitis (CFS/ME) is a disabling disease, in which people have great difficulties in carrying out their daily activities. Despite its high prevalence, there are still no effective tools for its diagnosis, monitoring and treatment. To better understand and promote follow-up, as well as stratify fatigue in these patients, Vall d’Hebron, the Universitat Autònoma de Barcelona (UAB) and the Universitat Politècnica de Catalunya · BarcelonaTech (UPC) have developed a mobile application that could be useful in the assessment of the severity of fatigue in this syndrome, especially in women. The results of the study in which this technology has been tested have been published in the journal Sensors.

The technology developed by the UAB and UPC researchers consists of a chest strap with a sensor capable of measuring certain cardiac hemodynamic variables, connected via Bluetooth to a mobile app. The mobile application allows you to record and monitor heart rate variability and share the analyzed results with the medical staff who supervise patients.

Specifically, this study analyzed the relationship between heart rate variability and severity of symptoms among women and men with CFS/ME. This parameter is closely related to heart rate, that is, the number of beats per minute of the heart. However, the time that passes between two consecutive beats is not always exactly the same, but small differences that fall within normality can be detected: this is what is known as heart rate variability (HRV).

In previous studies published in the Journal of Translational Medicine, HRV had already been related to the assessment of the severity of fatigue in women with CFS/ME. “Specifically, we had observed that this variability was lower in patients with CFS/ME, especially in the most disabling cases”, explains Dr. Jesús Castro, coordinator of the laboratory in Chronic Fatigue Syndrome / Myalgic Encephalomyelitis of the Rheumatology group of the Vall d’Hebron Research Institute (VHIR). A priori, it is considered positive to have a high variability, as it is an indicator of the proper functioning of the autonomic nervous system. “In this work we wanted to verify the relationship between HRV and the syndrome in both women and men with CFS/ME compared to healthy controls and its usefulness for monitoring patients”, adds Dr. Castro.

In line with previous studies, it was found that HRV measurement with mobile app technology could predict the severity of disabling fatigue in patients with chronic fatigue syndrome/myalgic encephalomyelitis. This was especially observed in the case of women, but this relationship was not so clear in the case of men. “We demonstrated that the use of the app would be especially useful for the monitoring of women suffering from this syndrome, which clearly have a lower variability of heart rate compared to healthy women”, says Dr. Rosa M Escorihuela, from the Department of Psychiatry and Legal Medicine of the UAB. Thus, HRV would be a good predictor marker of the severity of fatigue during the clinical course of the disease.

The study was carried out with 77 patients with this CFS/ME (32 men and 45 women) and their results were compared with those of a control group. The HRV evaluation was carried out in 3 sessions of 5 minutes, separated between one and three weeks and under controlled conditions.

This study has been carried out, in part, thanks to the R&D project PID2019-107473RB-C21, coordinated by researchers from the UAB and the UPC, and funded by the Ministry of Science and Innovation.

An improved non-invasive technology

Dr. Juan Ramos Castro, from the Electronic and Biomedical Instrumentation group and the Department of Electronic Engineering at the UPC, comments that “the experience of the UAB and UPC research groups has made it possible to correct the most important limitations presented by this technology such as errors in the measurement of cardiac variability produced by incorrect placement of the chest strap and / or the movement and breathing of the patient during recording, and obtaining the records under controlled conditions to reduce the influence of other external factors. The results of the analysis are stored in a single and secure server and can be consulted through a specific platform”. Dr. Lluís Capdevila, researcher at the Department of Basic, Evolutionary and Educational Psychology and the Sports Research Institute of the UAB, adds that “it is a non-invasive technology that is easy to use by patients or users, through your mobile device. In this way, they can perform self-assessments in ecological situations and could be monitored in real time”.

As Dr. Lluís Capdevila comments, “the same system originated and has been used successfully for real-time monitoring and follow-up of the relationship between physical effort and recovery, both in athletes and in the general population. For example, sports clubs such as Futbol Club Barcelona (women’s basketball and soccer sections) or New York City FC have used this system, and national teams such as the Spanish Basketball Federation, the Spanish Field Hockey Federation (men’s and female), or the Spanish Federation of Mountain Sports and Climbing”.

Vall d’Hebron, member of the European Network on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

In Catalonia it is estimated that there are currently between 350,000 and 500,000 people affected by chronic fatigue syndrome / myalgic encephalomyelitis, and 2 out of 3 affected people are women. Worldwide, a prevalence of between 17 and 25 million people with this affectation is estimated. In addition, these numbers are predicted to double by 2030 due to persistent COVID-19, a condition in which patients have similar symptoms: this is known as postviral chronic fatigue syndrome, which has been previously described in other coronaviruses (SARS-CoV-1 and MERS) for other viruses such as Ebola, Epstein-Barr and Cytomegalovirus.

Severe fatigue is the main symptom of CFS/ME, in addition to problems with immediate memory and speed of information processing and concentration, intolerance to physical / mental exercise, pain and dizziness. This syndrome can be very disabling, but even so, there are currently no diagnostic biomarkers or specific therapeutic options, so it is important that experts in the field work in a coordinated way to improve the care and management of these patients.

In this sense, Drs. José Alegre and Jesús Castro, both from Vall d’Hebron, are members for Spain in the European Network on Chronic Fatigue Syndrome / Myalgic Encephalomyelitis (EUROMENE), which includes 55 professionals from 22 European countries. A consensus document on therapeutic and diagnostic approaches for this syndrome was recently published in the journal Medicina.

This document brings together the diagnostic criteria used in the participating countries as well as the experience of professionals in the management and treatment of patients, taking into account both pharmacological and non-pharmacological therapies. In addition, experts present recommendations, from Europe and internationally, for the care of these patients. “It is necessary to have a health system that takes into account patients with chronic fatigue syndrome / myalgic encephalomyelitis, a pathology that has a great socioeconomic impact”, says Dr. José Alegre, from the Experience Unit in Syndromes of Central Awareness of the Rheumatology Service of the Vall d’Hebron University Hospital. Experts consider that it would be necessary to have between 2 and 4 specialist doctors for every million inhabitants with the support of a multidisciplinary team, such as nurses, physiotherapists, rehabilitators, occupational therapists, psychologists, nutritionists, social workers, etc.

It should be noted that not all countries have the same services for the care of patients with CFS/ME. In this sense, Catalonia is leading in terms of the care of these patients, since in our territory there are various units formed in this area to diagnose and treat this syndrome. Specifically, Vall d’Hebron has an Experience Unit in Central Sensitization Syndromes, within the Rheumatology Service, which works on both chronic fatigue syndrome / myalgic encephalomyelitis and fibromyalgia.

Insights from myalgic encephalomyelitis/chronic fatigue syndrome may help unravel the pathogenesis of postacute COVID-19 syndrome

Abstract:

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause chronic and acute disease. Postacute sequelae of SARS-CoV-2 infection (PASC) include injury to the lungs, heart, kidneys, and brain that may produce a variety of symptoms. PASC also includes a post-coronavirus disease 2019 (COVID-19) syndrome (‘long COVID’) with features that can follow other acute infectious diseases and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Here we summarize what is known about the pathogenesis of ME/CFS and of ‘acute’ COVID-19, and we speculate that the pathogenesis of post-COVID-19 syndrome in some people may be similar to that of ME/CFS. We propose molecular mechanisms that might explain the fatigue and related symptoms in both illnesses, and we suggest a research agenda for both ME/CFS and post-COVID-19 syndrome.

Source: Komaroff AL, Lipkin WI. Insights from myalgic encephalomyelitis/chronic fatigue syndrome may help unravel the pathogenesis of postacute COVID-19 syndrome. Trends Mol Med. 2021 Jun 7:S1471-4914(21)00134-9. doi: 10.1016/j.molmed.2021.06.002. Epub ahead of print. PMID: 34175230. https://pubmed.ncbi.nlm.nih.gov/34175230/

Broadband electrical impedance as a novel characterization of oxidative stress in single L6 skeletal muscle cells

Abstract:

Oxidative stress (OS) is one of the leading causes of cytotoxicity and is linked to many human physio-pathological conditions. In particular, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) induced by OS is debilitating to quality of life, while no clear biological markers have been identified for diagnostic measures. Recently, impedance measurements of peripheral blood cells of ME/CFS patients have been shown as a promising approach to diagnose the disease. Inspired by this study and aiming to interrogate muscle cells directly, we investigated if broadband measurements of single muscle cells could differentiate normal and oxidatively stressed cell populations.

We first optimized a protocol through H2O2 treatment to introduce oxidative stress to cultured rat L6 skeletal muscle cells. The treated cells were further characterized through broadband impedance spectroscopy of single cells using a microfluidic lab-on-a-chip system. The resulting dielectric properties of cytoplasm permittivity and conductivity are electrically distinct from normally cultured cells. The reflection and transmission coefficients, ΔS11 and ΔS21, of the normal cells are tightly clustered and closely resemble those of the cell-free solution across the frequency range of 9 kHz to 9 GHz. On the other hand, dielectric properties of the oxidized cells have a wide distribution in the GHz range, deviating both in the positive and negative directions from the normally cultured cells.

Simulation results guide our hypothesis that the dielectric differences could be linked to ion alterations, while calcium imaging directly supports the contribution of calcium flux to the observed deviation of S parameters. The unique electrical profile associated with oxidized cells in the GHz frequencies provide a framework for future development of technologies to diagnose oxidative-stress related diseases such as ME/CFS.

Source: Ferguson C, Pini N, Du X, Farina M, Hwang JMC, Pietrangelo T, Cheng X. Broadband electrical impedance as a novel characterization of oxidative stress in single L6 skeletal muscle cells. Anal Chim Acta. 2021 Aug 15;1173:338678. doi: 10.1016/j.aca.2021.338678. Epub 2021 May 25. PMID: 34172152. https://pubmed.ncbi.nlm.nih.gov/34172152/

Documenting disability in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

BACKGROUND: According to the 2015 National Academy of Medicine report, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) “is a serious, chronic, complex, and systemic disease that frequently and dramatically limits the activities of affected patients.” ME/CFS affects between 1 and 2.5 million Americans, leaving as many as 75% unable to work due to physical, cognitive and functional impairment. Unfortunately, many doctors and lawyers lack the knowledge of how to properly document an ME/CFS disability claim, leaving patients unable to access disability benefits.

OBJECTIVE: The goal of this article is to summarize the approaches used by experienced clinicians and lawyers in successful ME/CFS disability claims.

METHODS: The authors reviewed the types of US disability insurance programs and the evidence commonly required by these programs to demonstrate ME/CFS disability.

RESULTS: This article summarizes the range of methods used in successful US disability claims, which include documentation of the functional impact of post-exertional malaise and the use of methods that provide objective evidence of impairment.

CONCLUSIONS: Medical providers and lawyers can use these tested methods to obtain disability benefits for people with ME/CFS. Physical therapists, occupational therapists, and other specialists play an important role in providing objective evidence for ME/CFS disability claims.

Source: Podell, Richard, Dimmock, Mary E., and Comerford, Barbara B. ‘Documenting Disability in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)’. 1 Jan. 2020 : 339 – 352. https://content.iospress.com/articles/work/wor203178 (Full text)