Major Depressive Disorder and Chronic Fatigue Syndrome Show Characteristic Heart Rate Variability Profiles Reflecting Autonomic Dysregulations: Differentiation by Linear Discriminant Analysis.

Major depressive disorder (MDD) and chronic fatigue syndrome (CFS) have overlapping symptoms, and differentiation is important to administer the proper treatment. The present study aimed to assess the usefulness of heart rate variability (HRV) indices. Frequency-domain HRV indices, including high-frequency (HF) and low-frequency (LF) components, their sum (LF+HF), and their ratio (LF/HF), were measured in a three-behavioral-state paradigm composed of initial rest (Rest), task load (Task), and post-task rest (After) periods to examine autonomic regulation. It was found that HF was low at Rest in both disorders, but was lower in MDD than in CFS. LF and LF+HF at Rest were low only in MDD. Attenuated responses of LF, HF, LF+HF, and LF/HF to task load and an excessive increase in HF at After were found in both disorders. The results indicate that an overall HRV reduction at Rest may support a diagnosis of MDD. HF reduction was found in CFS, but with a lesser severity. Response disturbances of HRV to Task were observed in both disorders, and would suggest the presence of CFS when the baseline HRV has not been reduced. Linear discriminant analysis using HRV indices was able to differentiate MDD from CFS, with a sensitivity and specificity of 91.8% and 100%, respectively. HRV indices in MDD and CFS show both common and different profiles, and can be useful for the differential diagnosis.

Post-COVID-More than chronic fatigue?

After the first COVID-19 survivors were medically treated in Germany from spring 2020 onwards, various courses of the disease emerged that, in addition to the acute infection, led to prolonged symptoms (long COVID), but also to a symptomatic course beyond 12 weeks, which is referred to as "post-COVID syndrome" (PCS). Currently, the incidence of PCS is estimated to be approximately 15% of all symptomatically infected patients, although over- or underestimations may occur due to the soft definition and lack of control groups. The etiology of PCS is currently unknown. The following pathogenetic processes are discussed in particular: an endothelial dysfunction with microcirculatory disturbances and subsequent organ damage, a residual virus or virus particles, and/or an excessive autoimmune process. Due to the large number of organs that may be affected, PCS presents as a very complex clinical picture with up to 200 described symptoms. An evidence-based causal therapy for PCS has not yet been established. The guideline-based inpatient rehabilitation measures adapted to the individual patient resources have proven to be an effective therapy and should therefore be involved in the therapeutic concept at an early stage. Post-COVID syndrome is a multicomplex disease that can have a considerable impact on the quality of life, but also on the professional performance of the affected patients. Thus, it is clearly more than just a chronic fatigue syndrome. In the interest of our patients, treating physicians should take this disease seriously, clarify the differential diagnoses, and provide sensitive therapeutic care.

Towards a Better Understanding of the Complexities of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Long COVID.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex condition arising in susceptible people, predominantly following viral infection, but also other stressful events. The susceptibility factors discussed here are both genetic and environmental although not well understood. While the dysfunctional physiology in ME/CFS is becoming clearer, understanding has been hampered by different combinations of symptoms in each affected person. A common core set of mainly neurological symptoms forms the modern clinical case definition, in the absence of an accessible molecular diagnostic test. This landscape has prompted interest in whether ME/CFS patients can be classified into a particular phenotype/subtype that might assist better management of their illness and suggest preferred therapeutic options. Currently, the same promising drugs, nutraceuticals, or behavioral therapies available can be beneficial, have no effect, or be detrimental to each individual patient. We have shown that individuals with the same disease profile exhibit unique molecular changes and physiological responses to stress, exercise and even vaccination. Key features of ME/CFS discussed here are the possible mechanisms determining the shift of an immune/inflammatory response from transient to chronic in ME/CFS, and how the brain and CNS manifests the neurological symptoms, likely with activation of its specific immune system and resulting neuroinflammation. The many cases of the post viral ME/CFS-like condition, Long COVID, following SARS-CoV-2 infection, and the intense research interest and investment in understanding this condition, provide exciting opportunities for the development of new therapeutics that will benefit ME/CFS patients.

My experience with ME/CFS and implications: A personal narrative.

 Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic, debilitating health condition characterized by overwhelming fatigue and post-exertional malaise, or exacerbation of symptoms following physical, mental, or emotional exertion. ME/CFS often impacts every aspect of an individual's life, and one's new reality may be much different from the daily life experienced before the onset of the condition. Though the long-term effects of COVID-19 have brought increased attention to chronic fatigue and related disorders, ME/CFS is still vastly understudied and frequently misunderstood. People with ME/CFS are often passed between various healthcare providers as evidence-based treatments remain scarce. These patients are sometimes sent to rehabilitation professionals, who often lack appropriate education and experience with this patient population. This article describes the experience of a young woman and physical therapist with ME/CFS following COVID-19 infection, as well as potential implications for rehabilitation professionals and those who care for those with this condition.

Cardiovascular and haematological pathology in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): A role for viruses.

ME/CFS is a debilitating chronic condition that often develops after viral or bacterial infection. Insight from the study of Long COVID/Post Acute Sequelae of COVID-19 (PASC), the post-viral syndrome associated with SARS-CoV-2 infection, might prove to be useful for understanding pathophysiological mechanisms of ME/CFS. Disease presentation is similar between the two conditions, and a subset of Long COVID patients meet the diagnostic criteria for ME/CFS. Since Long COVID is characterized by significant vascular pathology - including endothelial dysfunction, coagulopathy, and vascular dysregulation - the question of whether or not the same biological abnormalities are of significance in ME/CFS arises. Cardiac abnormalities have for a while now been documented in ME/CFS cohorts, with recent studies demonstrating major deficits in cerebral blood flow, and hence vascular dysregulation. A growing body of research is demonstrating that ME/CFS is accompanied by platelet hyperactivation, anomalous clotting, a procoagulant phenotype, and endothelial dysfunction. Endothelial damage and dysregulated clotting can impair substance exchange between blood and tissues, and result in hypoperfusion, which may contribute to the manifestation of certain ME/CFS symptoms. Here we review the ME/CFS literature to summarize cardiovascular and haematological findings documented in patients with the condition, and, in this context, briefly discuss the potential role of previously-implicated pathogens. Overall, cardiac and haematological abnormalities are present within ME/CFS cohorts. While atherosclerotic heart disease is not significantly associated with ME/CFS, suboptimal cardiovascular function defined by reduced cardiac output, impaired cerebral blood flow, and vascular dysregulation are, and these abnormalities do not appear to be influenced by deconditioning. Rather, these cardiac abnormalities may result from dysfunction in the (autonomic) nervous system. Plenty of recently published studies are demonstrating significant platelet hyperactivity and endothelial dysfunction in ME/CFS, as well as anomalous clotting processes. It is of particular importance to determine to what extent these cardiovascular and haematological abnormalities contribute to symptom severity, and if these two systems can be targeted for therapeutic purposes. Viral reservoirs of herpesviruses exist in ME/CFS, and most likely contribute to cardiovascular and haematological dysfunction directly or indirectly. This review highlights the potential of studying cardiac functioning, the vasculature, and coagulation system in ME/CFS.

Feasibility Assessment of a School Nurse-Led Approach Using Chronic Absenteeism to Establish the School-Based Active Surveillance Process.

This article shares what was learned from the feasibility assessment of a nurse-led school-based active surveillance (SBAS) pilot to track chronic absenteeism using myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) as an exemplar. This pilot encompassed a 3-year period with training and feedback from school nurses (SNs) on data collection and ME/CFS. SNs found that the SBAS process helped them effectively identifying undiagnosed conditions. The assessment revealed the importance of focusing outreach efforts and establishing relationships with the school leadership in developing health policies and programs in the school setting. The pilot data were used to develop a manual to guide SNs for the SBAS process. This can be viewed as a model for SNs in establishing a surveillance to identify and track conditions like ME/CFS. With overlapping symptoms of Long COVID to ME/CFS, this assessment may provide insights for additional efforts to understand the impact of Long COVID on students' education.

Possible Application of Melatonin in Long COVID.

Clinical sequelae and symptoms for a considerable number of COVID-19 patients can linger for months beyond the acute stage of SARS-CoV-2 infection, "long COVID". Among the long-term consequences of SARS-CoV-2 infection, cognitive issues (especially memory loss or "brain fog"), chronic fatigue, myalgia, and muscular weakness resembling myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are of importance. Melatonin may be particularly effective at reducing the signs and symptoms of SARS-CoV-2 infection due to its functions as an antioxidant, anti-inflammatory, and immuno-modulatory agent. Melatonin is also a chronobiotic medication effective in treating delirium and restoring the circadian imbalance seen in COVID patients in the intensive care unit. Additionally, as a cytoprotector, melatonin aids in the prevention of several COVID-19 comorbidities, including diabetes, metabolic syndrome, and ischemic and non-ischemic cardiovascular diseases. This narrative review discusses the application of melatonin as a neuroprotective agent to control cognitive deterioration ("brain fog") and pain in the ME/CFS syndrome-like documented in long COVID. Further studies on the therapeutic use of melatonin in the neurological sequelae of SARS-CoV-2 infection are warranted.

Systemic antibody responses against human microbiota flagellins are overrepresented in chronic fatigue syndrome patients.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease with an unclear etiology and pathogenesis. Both an involvement of the immune system and gut microbiota dysbiosis have been implicated in its pathophysiology. However, potential interactions between adaptive immune responses and the microbiota in ME/CFS have been incompletely characterized. Here, we profiled antibody responses of patients with severe ME/CFS and healthy controls against microbiota and viral antigens represented as a phage-displayed 244,000 variant library. Patients with severe ME/CFS exhibited distinct serum antibody epitope repertoires against flagellins of Lachnospiraceae bacteria. Training machine learning algorithms on this antibody-binding data demonstrated that immune responses against gut microbiota represent a unique layer of information beyond standard blood tests, providing improved molecular diagnostics for ME/CFS. Together, our results point toward an involvement of the microbiota-immune axis in ME/CFS and lay the foundation for comparative studies with inflammatory bowel diseases and illnesses characterized by long-term fatigue symptoms, including post-COVID-19 syndrome.

[When COVID does not heal: post-COVID courses with fatigue and exercise intolerance]. / Wenn COVID nicht aufhört: Post-COVID-Verläufe mit Fatigue und Belastungsintoleranz.

Post-COVID-Syndrome consists of several pathobiologically different entities, ranging from damage to specific organs to new onset autoimmune diseases. This article focuses on post-COVID courses with the leading symptoms of fatigue and exercise intolerance. This category is also known from other infectious diseases and includes myalgic encephalomyelitis/chronic fatigue syndrome.

Post-viral fatigue in COVID-19: A review of symptom assessment methods, mental, cognitive, and physical impairment.

Coronavirus 2 is responsible for Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2), and the main sequela is persistent fatigue. Post-viral fatigue is common and affects patients with mild, asymptomatic coronavirus disease-2019 (COVID-19). However, the exact mechanisms involved in developing post-COVID-19 fatigue remain unclear. Furthermore, physical and cognitive impairments in these individuals have been widely described. Therefore, this review aims to summarize and propose tools from a multifaceted perspective to assess COVID-19 infection. Herein, we point out the instruments that can be used to assess fatigue in long-term COVID-19: fatigue in a subjective manner or fatigability in an objective manner. For physical and mental fatigue, structured questionnaires were used to assess perceived symptoms, and physical and cognitive performance assessment tests were used to measure fatigability using reduced performance.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: First Described Complication after Gam-COVID-Vac Vaccine.

BACKGROUND: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe, debilitating chronic disease characterized by marked tiredness and fatigue, cognitive dysfunction, sleep disturbances, pain, and autonomic, immunological, and metabolic dysfunctions, in which all symptoms are usually exacerbated by physical and/or psychological stress. SUBJECTS AND METHODS: We report a case of ME/CFS with severe myalgia and severe locomotor disorders in a 25-year-old female after Gam-COVID-Vac vaccine (Sputnik V) ten days before the manifestation of the symptoms. RESULTS: This is the first report of such a complication from the Gam-COVID-Vac vaccine.

Long-term neuromuscular consequences of SARS-Cov-2 and their similarities with myalgic encephalomyelitis/chronic fatigue syndrome: results of the retrospective CoLGEM study.

BACKGROUND: Patients with long-COVID often complain of continuous fatigue, myalgia, sleep problems, cognitive dysfunction, and post-exertional malaise. No data are available on EMG recording of evoked myopotentials (M-waves) or exercise-induced alterations in long-COVID patients, providing evidence of muscle membrane fatigue. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) develops in more than half of patients after an infectious disease, particularly viral diseases. A large proportion (around 70%) of these patients have neuromuscular disorders with M-wave alterations during and after exercise. Our hypothesis was that M-wave alterations would be also found in long-COVID patients, in association with neuromuscular symptoms, similar to ME/CFS. METHODS: This retrospective observational ColGEM (Covid LonG Encéphalomyelite Myalgique) study compared 59 patients with long-COVID and 55 ME/CFS patients with a history of severe infection who presented before the COVID pandemic. All of these patients underwent the same protocol consisting of a questionnaire focusing on neural and neuromuscular disorders and M-wave recording in the rectus femoris muscle before, during, and 10 min after a progressive cycling exercise. Maximal handgrip strength (MHGS) and maximal exercise power were also measured. The frequency of symptoms and magnitude of M-wave changes in the two groups were compared using non-parametric and parametric tests. RESULTS: The frequency of fatigue, myalgia, sleep problems, cognitive dysfunction, and post-exertional malaise as well as the magnitude of exercise-induced M-wave alterations were the same in the two groups. By contrast, digestive problems were less present in long-COVID. M-wave alterations were greater in ME/CFS patients as in those with long-COVID when the highest muscle strength and highest exercise performance were measured. CONCLUSIONS: These high clinical and biological similarities between long-COVID and ME/CFS support the hypothesis that SARS-Cov-2 infection can cause ME/CFS symptoms. Trial registration Registered retrospectively.

Chronic Fatigue Associated with Post-COVID Syndrome versus Transient Fatigue Caused by High-Intensity Exercise: Are They Comparable in Terms of Vascular Effects?

Purpose: The pathophysiology of chronic fatigue associated with post-COVID syndrome is not well recognized. It is assumed that this condition is partly due to vascular dysfunction developed during an acute phase of infection. There is great demand for a diagnostic tool that is able to clinically assess post-COVID syndrome and monitor the rehabilitation process. Patients and Methods: The Flow Mediated Skin Fluorescence (FMSF) technique appears uniquely suitable for the analysis of basal microcirculatory oscillations and reactive hyperemia induced by transient ischemia. The FMSF was used to measure vascular circulation in 45 patients with post-COVID syndrome. The results were compared with those for a group of 26 amateur runners before and after high-intensity exercise as well as for a control group of 32 healthy age-matched individuals. Results: Based on the observed changes in the NOI (Normoxia Oscillatory Index) and RHR (Reactive Hyperemia Response) parameters measured with the FMSF technique, it was found that chronic fatigue associated with post-COVID syndrome is comparable with transient fatigue caused by high-intensity exercise in terms of vascular effects, which are associated with vascular stress in the macrocirculation and microcirculation. Acute and chronic fatigue symptomatology shared similarly altered changes in the NOI and RHR parameters and both can be linked to calcium homeostasis modification. Conclusion: The NOI and RHR parameters measured with the FMSF technique can be used for non-invasive clinical assessment of post-COVID syndrome as well as for monitoring the rehabilitation process.

Understanding myalgic encephalomyelitis.

Myalgic encephalomyelitis and Long Covid have overlapping presentation.

A prospective observational study of post-COVID-19 chronic fatigue syndrome following the first pandemic wave in Germany and biomarkers associated with symptom severity.

A subset of patients has long-lasting symptoms after mild to moderate Coronavirus disease 2019 (COVID-19). In a prospective observational cohort study, we analyze clinical and laboratory parameters in 42 post-COVID-19 syndrome patients (29 female/13 male, median age 36.5 years) with persistent moderate to severe fatigue and exertion intolerance six months following COVID-19. Further we evaluate an age- and sex-matched postinfectious non-COVID-19 myalgic encephalomyelitis/chronic fatigue syndrome cohort comparatively. Most post-COVID-19 syndrome patients are moderately to severely impaired in daily live. 19 post-COVID-19 syndrome patients fulfill the 2003 Canadian Consensus Criteria for myalgic encephalomyelitis/chronic fatigue syndrome. Disease severity and symptom burden is similar in post-COVID-19 syndrome/myalgic encephalomyelitis/chronic fatigue syndrome and non-COVID-19/myalgic encephalomyelitis/chronic fatigue syndrome patients. Hand grip strength is diminished in most patients compared to normal values in healthy. Association of hand grip strength with hemoglobin, interleukin 8 and C-reactive protein in post-COVID-19 syndrome/non-myalgic encephalomyelitis/chronic fatigue syndrome and with hemoglobin, N-terminal prohormone of brain natriuretic peptide, bilirubin, and ferritin in post-COVID-19 syndrome/myalgic encephalomyelitis/chronic fatigue syndrome may indicate low level inflammation and hypoperfusion as potential pathomechanisms.

[Post-COVID syndrome with fatigue and exercise intolerance: myalgic encephalomyelitis/chronic fatigue syndrome]. / Post-COVID-Syndrom mit Fatigue und Belastungsintoleranz: Myalgische Enzephalomyelitis bzw. Chronisches Fatigue-Syndrom.

BACKGROUND: A sizable part of post-COVID syndrome meets the diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). A doubling of cases of ME/CFS within the next years is therefore projected. OBJECTIVES: Presentation of the current state of knowledge on ME/CFS. MATERIALS AND METHODS: Unsystematic review of the literature and of own contributions in research and patient care. RESULTS AND CONCLUSIONS: ME/CFS is a neuroimmunological disease, mostly infection-induced, usually persisting throughout life. Clinically it is characterized by fatigue lasting at least 6 months and the defining core feature of exercise intolerance (post-exertional malaise, PEM). Exercise intolerance is defined as a worsening of symptoms after (even mild) everyday exertion, which usually begins after several hours or on the following day, is still noticeable at least 14 h after exertion, and often lasts for several days (up to weeks or longer). Furthermore, ME/CFS is characterized by pain, disturbances of sleep, thinking and memory, and dysregulation of the circulatory, endocrine, and immune systems. As a separate clinical entity, ME/CFS should be distinguished from chronic fatigue, which occurs as a symptom of a range of very different diseases. The diagnosis of ME/CFS is made clinically using established international diagnostic criteria and requires careful stepwise diagnosis to exclude other diagnoses. A causal therapy for ME/CFS has not been established; the focus is on symptoms relief, treatment of the often accompanying orthostatic intolerance, and assistance with anticipatory energy management (pacing).

Clinical Characteristics of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Diagnosed in Patients with Long COVID.

Background and Objectives: COVID-19 can be serious not only in the acute phase but also after the acute phase and some patients develop ME/CFS. There have been few studies on patients with long COVID in whom ME/CFS was diagnosed by physicians based on standardized criteria after examinations and exclusion diagnosis and not based on only subjective symptoms. The purpose of this study was to elucidate the detailed characteristics of ME/CFS in patients with long COVID. Materials and Methods: A retrospective descriptive study was performed for patients who visited a COVID-19 aftercare clinic established in Okayama University Hospital during the period was from February 2021 to April 2022. Results: Clinical data were obtained from medical records for 281 patients, and 279 patients who met the definition of long COVID were included. The overall prevalence rate of ME/CFS diagnosed by three sets of ME/CFS criteria (Fukuda, Canadian and IOM criteria) was 16.8% (48.9% in male and 51.1% in females). The most frequent symptoms in ME/CFS patients were general fatigue and post-exertional malaise (89.4% of the patients), headache (34.0%), insomnia (23.4%), dysosmia (21.3%) and dysgeusia (19.1%). Dizziness, chest pain, insomnia and headache were characteristic symptoms related to ME/CFS. The male to female ratio in ME/CFS patients was equal in the present study, although ME/CFS was generally more common in women in previous studies. Given that patients with ME/CFS had more severe conditions in the acute phase of COVID-19, the severity of the acute infectious state might be involved in the pathophysiology of ME/CFS. Conclusions: The prevalence rate of ME/CFS and the characteristic sequelae in the long COVID condition were revealed in this study.

[Post-COVID syndrome-Focus fatigue]. / Post-COVID-Syndrom ­ Fokus Fatigue.

The World Health Organization (WHO) defines post-coronavirus disease 2019 (COVID-19) as a condition which occurs in individuals with a history of probable or confirmed severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection 3 months after the onset of COVID-19 symptoms, lasts for at least 2 months and cannot be explained by an alternative diagnosis. Core symptoms of post-COVID syndrome are fatigue, dyspnea and cognitive dysfunction, which have an impact on everyday functional level. Neuropsychiatric late sequelae are common in COVID-19 patients, with incidence rates over 30%. Beside the abovementioned core symptoms, sleep disorders, depression and anxiety show increased incidences. According to current opinion, associated neuropsychiatric symptoms are subsumed under the term post-COVID syndrome but are also interpreted as comorbidities, which can promote the manifestation of a post-COVID syndrome. The key symptom fatigue shows symptom overlapping and comorbidity with psychiatric disorders. Imaging studies indicate an organic correlate of fatigue in post-COVID patients. Furthermore, psychosocial aspects and psychiatric comorbidities, such as depression and anxiety disorders as modulating and therefore potentially treatable factors were identified. Treatment of fatigue consists of pharmacological management with stimulants and antidepressants as well as nonpharmacological strategies, most notably cognitive behavioral therapy and exercise-focused interventions. The evidence for this comes from meta-analyses of tumor-associated or post-viral fatigue.