Tag: long covid symptoms

Cardiac Autonomic Function in Long COVID-19 Using Heart Rate Variability: An Observational Cross-Sectional Study

Abstract:

Background: Heart rate variability is a non-invasive, measurable, and established autonomic nervous system test. Long-term COVID-19 sequelae are unclear; however, acute symptoms have been studied.

Objectives: To determine autonomic cardiac differences between long COVID-19 patients and healthy controls and evaluate associations among symptoms, comorbidities, and laboratory findings.

Methods: This single-center study included long COVID-19 patients and healthy controls. The heart rate variability (HRV), a quantitative marker of autonomic activity, was monitored for 24 h using an ambulatory electrocardiogram system. HRV indices were compared between case and control groups. Symptom frequency and inflammatory markers were evaluated. A significant statistical level of 5% (p-value 0.05) was adopted.

Results: A total of 47 long COVID-19 patients were compared to 42 healthy controls. Patients averaged 43.8 (SD14.8) years old, and 60.3% were female. In total, 52.5% of patients had moderate illness. Post-exercise dyspnea was most common (71.6%), and 53.2% lacked comorbidities. CNP, D-dimer, and CRP levels were elevated (p-values of 0.0098, 0.0023, and 0.0015, respectively). The control group had greater SDNN24 and SDANNI (OR = 0.98 (0.97 to 0.99; p = 0.01)). Increased low-frequency (LF) indices in COVID-19 patients (OR = 1.002 (1.0001 to 1.004; p = 0.030)) and high-frequency (HF) indices in the control group (OR = 0.987 (0.98 to 0.995; p = 0.001)) were also associated.

Conclusions: Patients with long COVID-19 had lower HF values than healthy individuals. These variations are associated with increased parasympathetic activity, which may be related to long COVID-19 symptoms and inflammatory laboratory findings.

Source: Menezes Junior ADS, Schröder AA, Botelho SM, Resende AL. Cardiac Autonomic Function in Long COVID-19 Using Heart Rate Variability: An Observational Cross-Sectional Study. J Clin Med. 2022 Dec 22;12(1):100. doi: 10.3390/jcm12010100. PMID: 36614901; PMCID: PMC9821736. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9821736/ (Full text)

Improvement of Long COVID symptoms over one year

Abstract:

Importance: Early and accurate diagnosis and treatment of Long COVID, clinically known as post-acute sequelae of COVID-19 (PASC), may mitigate progression to chronic diseases such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Our objective was to determine the utility of the DePaul Symptom Questionnaire (DSQ) to assess the frequency and severity of common symptoms of ME/CFS, to diagnose and monitor symptoms in patients with PASC.

Methods: This prospective, observational cohort study enrolled 185 people that included 34 patients with PASC that had positive COVID-19 test and persistent symptoms of >3 months and 151 patients diagnosed with ME/CFS. PASC patients were followed over 1 year and responded to the DSQ at baseline and 12 months. ME/CFS patients responded to the DSQ at baseline and 1 year later. Changes in symptoms over time were analyzed using a fixed-effects model to compute difference-in-differences estimates between baseline and 1-year follow-up assessments.

Participants: Patients were defined as having PASC if they had a previous positive COVID-19 test, were experiencing symptoms of fatigue, post-exertional malaise, or other unwellness for at least 3 months, were not hospitalized for COVID-19, had no documented major medical or psychiatric diseases prior to COVID-19, and had no other active and untreated disease processes that could explain their symptoms. PASC patients were recruited in 2021. ME/CFS patients were recruited in 2017.

Results: At baseline, patients with PASC had similar symptom severity and frequency as patients with ME/CFS and satisfied ME/CFS diagnostic criteria. ME/CFS patients experienced significantly more severe unrefreshing sleep and flu-like symptoms. Five symptoms improved significantly over the course of 1 year for PASC patients including fatigue, post-exertional malaise, brain fog, irritable bowel symptoms and feeling unsteady. In contrast, there were no significant symptom improvements for ME/CFS patients.

Conclusion and relevance: There were considerable similarities between patients with PASC and ME/CFS at baseline. However, symptoms improved for PASC patients over the course of a year but not for ME/CFS patients. PASC patients with significant symptom improvement no longer met ME/CFS clinical diagnostic criteria. These findings indicate that the DSQ can be used to reliably assess and monitor PASC symptoms.

Source: Oliveira CR, Jason LA, Unutmaz D, Bateman L, Vernon SD. Improvement of Long COVID symptoms over one year. Front Med (Lausanne). 2023 Jan 9;9:1065620. doi: 10.3389/fmed.2022.1065620. PMID: 36698810; PMCID: PMC9868805. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9868805/ (Full text)

Hyperbaric oxygen therapy for long COVID (HOT-LoCO), an interim safety report from a randomised controlled trial

Abstract:

Background: With ~ 50 million individuals suffering from post-COVID condition (PCC), low health related quality of life (HRQoL) is a vast problem. Common symptoms of PCC, that persists 3 months from the onset of COVID-19 are fatigue, shortness of breath and cognitive dysfunction. No effective treatment options have been widely adopted in clinical practice. Hyperbaric oxygen (HBO2) is a candidate drug.

Methods: The objective of this interim analysis is to describe our cohort and evaluate the safety of HBO2 for post covid condition. In an ongoing randomised, placebo-controlled, double blind, clinical trial, 20 previously healthy subjects with PCC were assigned to HBO2 or placebo. Primary endpoints are physical domains in RAND-36; Physical functioning (PF) and Role Physical (RP) at 13 weeks. Secondary endpoints include objective physical tests. Safety endpoints are occurrence, frequency, and seriousness of Adverse Events (AEs). An independent data safety monitoring board (DSMB) reviewed unblinded data. The trial complies with Good Clinical Practice. Safety endpoints are evaluated descriptively. Comparisons against norm data was done using t-test.

Results: Twenty subjects were randomised, they had very low HRQoL compared to norm data. Mean (SD) PF 31.75 (19.55) (95% Confidence interval; 22.60-40.90) vs 83.5 (23.9) p < 0.001 in Rand-36 PF and mean 0.00 (0.00) in RP. Very low physical performance compared to norm data. 6MWT 442 (180) (95% CI 358-525) vs 662 (18) meters p < 0.001. 31 AEs occurred in 60% of subjects. In 20 AEs, there were at least a possible relationship with the study drug, most commonly cough and chest pain/discomfort.

Conclusions: An (unexpectedly) high frequency of AEs was observed but the DSMB assessed HBO2 to have a favourable safety profile. Our data may help other researchers in designing trials.

Trial Registration ClinicalTrials.gov: NCT04842448. Registered 13 April 2021, https://clinicaltrials.gov/ct2/show/NCT04842448 . EudraCT: 2021-000764-30. Registered 21 May 2021, https://www.clinicaltrialsregister.eu/ctr-search/trial/2021-000764-30/SE.

Source: Kjellberg A, Hassler A, Boström E, El Gharbi S, Al-Ezerjawi S, Kowalski J, Rodriguez-Wallberg KA, Bruchfeld J, Ståhlberg M, Nygren-Bonnier M, Runold M, Lindholm P. Hyperbaric oxygen therapy for long COVID (HOT-LoCO), an interim safety report from a randomised controlled trial. BMC Infect Dis. 2023 Jan 20;23(1):33. doi: 10.1186/s12879-023-08002-8. PMID: 36670365; PMCID: PMC9854077. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9854077/ (Full text)

Two-Years Follow-Up of Symptoms and Return to Work in Complex Post-COVID-19 Patients

Abstract:

Introduction: Many COVID-19 patients present with severe long-lasting symptoms. They might benefit from a coordination team to manage such complex situations, but late efficacy still needs to be determined.
Population and Methods: Out of 105 contacts, 45 patients had two phone consultations separated by personalized support 15 and 22 months, respectively, after COVID infection. Self-reported symptoms, feelings of improvement and ability to return to work allowed us to determine the efficacy of the therapeutic strategy proposed.
Results: Unlike what was expected, many post-COVID-19 patients directly contacted the coordination team and had significant pre-existing comorbidities. Despite exercise, respiratory, olfactory rehabilitations, cognition/speech therapy and/or psychological support, the more frequent self-reported symptoms (fatigue, neurocognitive disorders, muscles and joint pain) did not resolve. However, dyspnea, anxiety and chest pain were significantly reduced. Finally, 2/3 of the patients felt some degree of improvement and returned to work either partially or fully, but 1/3 remained complaining of symptoms and out of work as late as 22 months after COVID occurrence. All patients greatly appreciated the second phone consultation.
Conclusions: In such complex situations, besides early and adapted rehabilitations and psychological help allowing better symptom management, relatively simple actions such as a phone call might be very useful to reduce patients’ feelings of abandonment.
Source: Van Wambeke E, Bezler C, Kasprowicz A-M, Charles A-L, Andres E, Geny B. Two-Years Follow-Up of Symptoms and Return to Work in Complex Post-COVID-19 Patients. Journal of Clinical Medicine. 2023; 12(3):741. https://doi.org/10.3390/jcm12030741 https://www.mdpi.com/2077-0383/12/3/741 (Full text)

Long-COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): Potential neurophysiological biomarkers for these enigmatic entities

Since early in the pandemic, fatigue has been recognized as one of the most common persistent complaints in individuals infected with SARS-CoV-2, and constitutes one main symptom of the so-called long-COVID syndrome. The term fatigue refers to a sustained feeling of tiredness, which can be present at rest; it is not directly related to physical activity, but can be exacerbated disproportionally by exertion.

Survivors of other recent coronavirus outbreaks, such as severe acute respiratory syndrome (SARS) in 2002 and Middle East respiratory syndrome (MERS) in 2012 also developed chronic fatigue. These ‘post-infectious’ fatigue syndromes, including long-COVID, resemble myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a chronic disorder of unknown physiopathology characterized by fatigue, post-exertional malaise, chronic muscle or skeletal pain, and cognitive impairment (‘brain fog’).

Despite it being an extremely disabling symptom, the results of routine examinations are often normal in patients complaining of lingering fatigue, a phenomenon that has also led the medical-scientific community to view this condition with skepticism.

In physiology, fatigue is defined as a decrease in the maximal force-generating capacity of a muscle during exercise. It may result from peripheral processes distal to the neuromuscular junction and from central processes controlling the discharge rate of motoneurons.

Physical fatigue related to both central and peripheral nervous system dysfunction can be assessed with neurophysiological techniques including transcranial magnetic stimulation (TMS) of the motor cortex, electrical stimulation of nerve trunks or intramuscular nerve fibers, and electromyography (EMG) recordings.

In August 2021, the first study showing myopathic changes in quantitative EMG (qEMG) in long-COVID patients with musculoskeletal symptoms was published (). The same authors demonstrated myopathic qEMG features and histopathological changes in skeletal muscle biopsies in 16 patients with complaints of fatigue, myalgia, and/or weakness persisting for up to 14 months after mild to moderate COVID-19 (). The wide variety of histological changes in this study, including muscle fiber atrophy, mitochondrial changes, subsarcolemmal accumulation, inflammation, capillaries alteration, suggests that skeletal muscle may be a major target of SARS-CoV-2.

On the opposite side of the neuroaxis, dysfunction in the activity of the primary motor cortex and reduced corticomotor output may underlie fatigue.

The first TMS study on motor cortex physiology was conducted on 12 patients with long-term fatigue and ‘brain fog’ after severe COVID-19 (). It showed disruption of the physiological mechanism of post-contraction depression, i.e., the transient decrease in the amplitude of motor evoked potentials and prolongation of the cortical silent period after a fatiguing motor task, which depends on cortical inhibitory mechanisms and has the protective purpose of preventing muscle overload. Impairment of intracortical GABAergic activity, as indicated by disrupted long-interval intracortical inhibition, together with reduced excitability of the primary motor cortex was subsequently demonstrated in 67 patients with fatigue and cognitive difficulties after mild COVID-19 (). These patients also presented selective deficits in executive functions. Based on these findings, the authors proposed that fatigue depends on altered excitability and neurotransmission within the motor cortex at rest, and on abnormal reactivity to muscular exercise. In addition, reduced executive control may contribute to exacerbating poor physical performance and fatigue tolerance ().

These objective neurophysiological and histopathological findings showed for the first time that fatigue may due both to pathological processes in the muscle (the effector of the motor command) and/or at the site of motor command processing. The mechanisms of chronic dysfunction of neural and muscle cells may be sustained by inflammation or dysimmunity, triggered by SARS-COV-2 in predisposed individuals.

Immune-inflammatory and neuroendocrine mechanisms have also been implicated in ME/CFS. In particular, increased production of autoantibodies against CNS and autonomic nervous system targets, such as the ß2 adrenergic receptor (ß2AdR), have been documented (). As ß2AdR are important vasodilators, their functional disturbance may result in vasoconstriction and hypoxemia with chronic muscular and cerebral hypoperfusion.

The COVID-19 pandemic is likely to greatly increase the incidence of ME/CFS, so that the intense research on the pathophysiological mechanisms of fatigue in long-COVID can help to shed light on a poorly understood and underestimated syndrome.

Source: Versace V, Tankisi H. Long-COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): Potential neurophysiological biomarkers for these enigmatic entities. Clin Neurophysiol. 2023 Jan 13;147:58-59. doi: 10.1016/j.clinph.2023.01.001. Epub ahead of print. PMID: 36657309; PMCID: PMC9838078. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9838078/ (Full text)

Epidemiology, symptomatology, and risk factors for long COVID symptoms: Multi-centre study

Abstract:

Background: Long COVID induces a substantial global burden of disease. The pathogenesis, complications, epidemiological and clinical characteristics of COVID-19 patients in the acute phase have been evaluated, while few studies have characterized the epidemiology, symptomatology and risk factors of long COVID symptoms. Its characteristics among coronavirus disease 2019 (COVID-19) patients in the general population remain unaddressed.

Objective: We examined the prevalence of long COVID symptoms, its symptom patterns, and its risk factors. we aimed to fill the knowledge gaps by evaluating the prevalence of long COVID symptoms in four major Chinese cities.

Methods: We performed a population-based, multi-centre survey by a representative sampling strategy via the Qualtrics platform in Beijing, Shanghai, Guangzhou and Hong Kong (June 2022). We included 2,712 community-dwelling, COVID-19 patients, and measured the prevalence of long COVID symptoms defined by the WHO, and their risk factors. The primary outcomes were the symptoms of long COVID with various levels of impact. A descriptive analysis was conducted on the prevalence and distribution of the long COVID symptoms according to disease severity. A sensitivity analysis of increasing the number of long COVID symptoms was also conducted. A univariate and multivariate regression analysis was performed to examine the risk factors of severe long COVID symptoms, including age, gender, marital status, current occupation, educational level, living status, smoking habits, monthly household income, self-perceived health status, presence of chronic diseases, use of chronic medication, COVID-19 vaccination status, and severity of COVID-19.

Results: The response rate was 63.6%. The prevalence of long COVID, moderate or severe long COVID, and severe long COVID was 90.4%, 62.4%, and 31.0%, respectively. Fatigue (33.7%), cough (31.9%), sore throat (31.0%), difficulty in concentration (30.5%), feeling of anxiety (30.2%), myalgia (29.9%), and arthralgia (29.9%) were the most common severe long COVID symptoms. From multivariate regression analysis, female gender (adjusted odds ratio [aOR]=1.49, 95% C.I.=1.13-1.95), engagement in transportation, logistics, or discipline workforce (aOR=2.52, 95% C.I.=1.58-4.03), living with domestic workers (aOR=2.37, 95% C.I.=1.39-4.03), smoking (aOR=1.55, 95% C.I.=1.17-2.05), poor self-perceived health status (aOR 5.06 to 15.38), chronic diseases (aOR 1.92 to 2.71), chronic medication use (aOR=4.38, 95% C.I.=1.66-11.53), and critical severity of COVID-19 (aOR=1.52, 95% C.I.=1.07-2.15) were associated with severe long COVID. Prior vaccination for ≥2 doses of COVID-19 was a protective factor (aOR=0.35-0.22, 95% C.I.=0.08-0.90).

Conclusions: We have examined the prevalence of long COVID symptoms in four Chinese cities according to the severity of COVID-19. We also evaluated the pattern of long COVID symptoms, and their risk factors. These findings may inform early identification of COVID-19 patients at risk of long COVID and planning of rehabilitative services.

Source: Wong MC, Huang J, Wong NY, Wong GL, Yip TC, Chan RN, Chau SW, Ng SC, Wing YK, Chan FK. Epidemiology, symptomatology, and risk factors for long COVID symptoms: Multi-centre study. JMIR Public Health Surveill. 2023 Jan 12. doi: 10.2196/42315. Epub ahead of print. PMID: 36645453. https://pubmed.ncbi.nlm.nih.gov/36645453/

Long COVID Symptomatology and Associated Factors in Primary Care Patients: The EPICOVID-AP21 Study

Abstract:

Persistent COVID-19 condition includes a wide variety of symptoms and health problems of indeterminate duration. The present study examined the sociodemographic and clinical characteristics of the population with Long COVID seen in Primary Care using a questionnaire based on the existing scientific literature. It was an observational and descriptive study of the characteristics of the Spanish population with Long COVID over 14 years of age.
The responses were analysed by means of a descriptive analysis of the variables recorded, in addition to a bivariate analysis to determine the existence of a relationship between persistent COVID-19 and variables such as gender, age, vaccination status or concomitant pathology. The results obtained clearly describe the sociodemographic characteristics of the population, highlighting the predominance of female gender and the prevalence of tiredness and fatigue.
Furthermore, relevant information was obtained on the differences in symptomatology according to gender, age, previous pathologies and alterations derived from infection and/or vaccination. These data are important for better detection, diagnosis and treatment of Long COVID and the improvement of the quality of life of this population.
Source: Romero-Rodríguez E, Perula-de-Torres LÁ, González-Lama J, Castro-Jiménez RÁ, Jiménez-García C, Priego-Pérez C, Vélez-Santamaría R, Simón-Vicente L, González-Santos J, González-Bernal JJ. Long COVID Symptomatology and Associated Factors in Primary Care Patients: The EPICOVID-AP21 Study. Healthcare. 2023; 11(2):218. https://doi.org/10.3390/healthcare11020218 https://www.mdpi.com/2227-9032/11/2/218 (Full text)

Long covid outcomes at one year after mild SARS-CoV-2 infection: nationwide cohort study

Abstract:

Objectives: To determine the clinical sequelae of long covid for a year after infection in patients with mild disease and to evaluate its association with age, sex, SARS-CoV-2 variants, and vaccination status.

Design: Retrospective nationwide cohort study.

Setting: Electronic medical records from an Israeli nationwide healthcare organisation.

Population: 1 913 234 Maccabi Healthcare Services members of all ages who did a polymerase chain reaction test for SARS-CoV-2 between 1 March 2020 and 1 October 2021.

Main outcome measures: Risk of an evidence based list of 70 reported long covid outcomes in unvaccinated patients infected with SARS-CoV-2 matched to uninfected people, adjusted for age and sex and stratified by SARS-CoV-2 variants, and risk in patients with a breakthrough SARS-CoV-2 infection compared with unvaccinated infected controls. Risks were compared using hazard ratios and risk differences per 10 000 patients measured during the early (30-180 days) and late (180-360 days) time periods after infection.

Results: Covid-19 infection was significantly associated with increased risks in early and late periods for anosmia and dysgeusia (hazard ratio 4.59 (95% confidence interval 3.63 to 5.80), risk difference 19.6 (95% confidence interval 16.9 to 22.4) in early period; 2.96 (2.29 to 3.82), 11.0 (8.5 to 13.6) in late period), cognitive impairment (1.85 (1.58 to 2.17), 12.8, (9.6 to 16.1); 1.69 (1.45 to 1.96), 13.3 (9.4 to 17.3)), dyspnoea (1.79 (1.68 to 1.90), 85.7 (76.9 to 94.5); 1.30 (1.22 to 1.38), 35.4 (26.3 to 44.6)), weakness (1.78 (1.69 to 1.88), 108.5, 98.4 to 118.6; 1.30 (1.22 to 1.37), 50.2 (39.4 to 61.1)), and palpitations (1.49 (1.35 to 1.64), 22.1 (16.8 to 27.4); 1.16 (1.05 to 1.27), 8.3 (2.4 to 14.1)) and with significant but lower excess risk for streptococcal tonsillitis and dizziness. Hair loss, chest pain, cough, myalgia, and respiratory disorders were significantly increased only during the early phase. Male and female patients showed minor differences, and children had fewer outcomes than adults during the early phase of covid-19, which mostly resolved in the late period. Findings remained consistent across SARS-CoV-2 variants. Vaccinated patients with a breakthrough SARS-CoV-2 infection had a lower risk for dyspnoea and similar risk for other outcomes compared with unvaccinated infected patients.

Conclusions: This nationwide study suggests that patients with mild covid-19 are at risk for a small number of health outcomes, most of which are resolved within a year from diagnosis.

Source: Mizrahi B, Sudry T, Flaks-Manov N, Yehezkelli Y, Kalkstein N, Akiva P, Ekka-Zohar A, Ben David SS, Lerner U, Bivas-Benita M, Greenfeld S. Long covid outcomes at one year after mild SARS-CoV-2 infection: nationwide cohort study. BMJ. 2023 Jan 11;380:e072529. doi: 10.1136/bmj-2022-072529. PMID: 36631153; PMCID: PMC9832503. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9832503/ (Full text)

Clinical Characteristics in the Acute Phase of COVID-19 That Predict Long COVID: Tachycardia, Myalgias, Severity, and Use of Antibiotics as Main Risk Factors, While Education and Blood Group B Are Protective

Abstract:

Background: Risk factors for developing long COVID are not clearly established. The present study was designed to determine if any sign, symptom, or treatment of the acute phase, or personal characteristics of the patient, is associated with the development of long COVID.
Methods: A cohort study was carried out, randomly selecting symptomatic COVID-19 patients and not vaccinated. The severity of the acute illness was assessed through the number of compatible COVID-19 symptoms, hospitalizations, and the symptom severity score using a 10-point visual analog scale.
Results: After multivariate analysis, a severity score ≥8 (RR 2.0, 95%CI 1.1–3.5, p = 0.022), hospitalization (RR 2.1, 95%CI 1.0–4.4, p = 0.039), myalgia (RR 1.9, 95%CI 1.08–3.6, p = 0.027), tachycardia (RR 10.4, 95%CI 2.2–47.7, p = 0.003), and use of antibiotics (RR 2.0, 95%CI 1.1–3.5, p = 0.022), was positively associated with the risk of having long COVID. Higher levels of education (RR 0.6, 95%CI 0.4–0.9, p = 0.029) and type positive B blood group (B + AB, RR 0.44, 95%CI 0.2–0.9, p = 0.044) were protective factors. The most important population attributable fractions (PAFs) for long COVID were myalgia (37%), severity score ≥8 (31%), and use of antibiotics (27%).
Conclusions: Further studies in diverse populations over time are needed to expand the knowledge that could lead us to prevent and/or treat long COVID.
Source: Guzman-Esquivel J, Mendoza-Hernandez MA, Guzman-Solorzano HP, Sarmiento-Hernandez KA, Rodriguez-Sanchez IP, Martinez-Fierro ML, Paz-Michel BA, Murillo-Zamora E, Rojas-Larios F, Lugo-Trampe A, Plata-Florenzano JE, Delgado-Machuca M, Delgado-Enciso I. Clinical Characteristics in the Acute Phase of COVID-19 That Predict Long COVID: Tachycardia, Myalgias, Severity, and Use of Antibiotics as Main Risk Factors, While Education and Blood Group B Are Protective. Healthcare. 2023; 11(2):197. https://doi.org/10.3390/healthcare11020197 https://www.mdpi.com/2227-9032/11/2/197 (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)