Autonomic dysfunction in 'long COVID': rationale, physiology and management strategies

A Post-Pandemic Enigma: The Cardiovascular Impact of Post-Acute Sequelae of SARS-CoV-2

COVID-19 has become the first modern-day pandemic of historic proportion, affecting >600 million individuals worldwide and causing >6.5 million deaths. While acute infection has had devastating consequences, postacute sequelae of SARS-CoV-2 infection appears to be a pandemic of its own, impacting up to one-third of survivors and often causing symptoms suggestive of cardiovascular phenomena. This review will highlight the suspected pathophysiology of postacute sequelae of SARS-CoV-2, its influence on the cardiovascular system, and potential treatment strategies.

Cardiorespiratory Response to Six-Minute Step Test in Post COVID-19 Patients-A Cross Sectional Study

BACKGROUND AND PURPOSE

New coronavirus disease 2019 (COVID-19) can cause persistent symptoms and physical weakness that can lead to a limitation in activities of daily living (ADL). There is a lack of evidence about the performance in the six-minute step test (6MST) of post-COVID-19 patients and healthy subjects. The aim of this study is to investigate the cardiorespiratory response induced by the 6MST in post-COVID-19 patients and compare it with the response of the six-minute walk test (6MWT).

METHODS

This cross-sectional study was conducted on 34 post-COVID-19 patients and 33 healthy subjects. The assessment was performed at one month from a non-severe SARS-CoV-2 infection. Both groups were assessed by using the 6MST, 6MWT, and the pulmonary function test (PFT). Post COVID functional status (PCFS) scale was used for the post-COVID-19 group to assess functional status. Physiological responses; heart rate (HR), respiratory rate (RR), oxygen saturation (SpO₂), blood pressure (BP), and Borg scale for fatigue and dyspnea were recorded before and after the 6MST and 6MWT.

RESULTS

the performance of the post-COVID-19 group was worse than the healthy group in both tests. In 6MWT, the distance walked by the post-COVID-19 group (423 ± 7) was 94 m less than the healthy group, and the number of climbed steps in the 6MST (121 ± 4) was 34 steps less than the healthy group. Both results were statistically significant (p < 0.001). There was a moderate positive correlation between the 6MST and 6MWT in walked distance versus steps number (r = 0.5, p < 0.001). In addition, there was a moderate correlation between the two tests in the post (HR, RR, SpO₂, systolic blood pressure SBP, diastolic blood pressure DBP, dyspnea, and fatigue) with p < 0.001.

CONCLUSIONS

Six-minute step tests produced similar cardiorespiratory responses when compared to a 6MWT. The 6MST can be used as an assessment tool for COVID-19 patients to evaluate their functional capacity and ADL.

Clinical surrogates of dysautonomia predict lethal outcome in COVID-19 on intensive care unit

BACKGROUND

Unpredictable vegetative deteriorations made the treatment of patients with acute COVID-19 on intensive care unit particularly challenging during the first waves of the pandemic. Clinical correlates of dysautonomia and their impact on the disease course in critically ill COVID-19 patients are unknown.

METHODS

We retrospectively analyzed data collected during a single-center observational study (March 2020-November 2021) which was performed at the University Medical Center Hamburg-Eppendorf, a large tertiary medical center in Germany. All patients admitted to ICU due to acute COVID-19 disease during the study period were included (n = 361). Heart rate variability (HRV) and blood pressure variability (BPV) per day were used as clinical surrogates of dysautonomia and compared between survivors and non-survivors at different time points after admission. Intraindividual correlation of vital signs with laboratory parameters were calculated and corrected for age, sex and disease severity.

RESULTS

Patients who deceased in ICU had a longer stay (median days ± IQR, survivors 11.0 ± 27.3, non-survivors 14.1 ± 18.7, P = 0.85), in contrast time spent under invasive ventilation was not significantly different (median hours ± IQR, survivors 322 ± 782, non-survivors 286 ± 434, P = 0.29). Reduced HRV and BPV predicted lethal outcome in patients staying on ICU longer than 10 days after adjustment for age, sex, and disease severity. Accordingly, HRV was significantly less correlated with inflammatory markers (e.g. CRP and Procalcitonin) and blood carbon dioxide in non-survivors in comparison to survivors indicating uncoupling between autonomic function and inflammation in non-survivors.

CONCLUSIONS

Our study suggests autonomic dysfunction as a contributor to mortality in critically ill COVID-19 patients during the first waves of the pandemic. Serving as a surrogate for disease progression, these findings could contribute to the clinical management of COVID-19 patients admitted to the ICU. Furthermore, the suggested measure of dysautonomia and correlation with other laboratory parameters is non-invasive, simple, and cost-effective and should be evaluated as an additional outcome parameter in septic patients treated in the ICU in the future.

[Outpatient rehabilitative care for patients with Long-COVID - a guideline-based clinical practice guideline]

BACKGROUND

Even after weeks and months, persisting and also newly occurring symptoms after SARS-CoV-2 infection are common and lead in many cases to a broad spectrum of impairments and participation restrictions in all areas of daily life. Scientific evidence on therapeutic options still is limited. The aim of this work is therefore to provide pragmatic treatment recommendations analogous to the current therapeutic appliances guideline.

METHOD

In addition to a search in six electronic databases, the experiences from the treatment of more than hundred affected persons from the post-COVID outpatient rehabilitation service were used. Additionally, experiences with patients with similar symptoms from other diseases were included. All authors worked together to develop the pragmatic recommendations for the treatment of the main symptoms within the framework of outpatient therapy measures. A list of recommended diagnostics and functional assessments prior to therapy was also developed.

RESULTS

For the main symptoms fatigue, dyspnoea and cognitive impairment, the catalog of therapeutic products offers a wide range of therapeutic options under the diagnosis U09.9. The therapy packages should be composed individually and adapted to the patient's performance level that regularly should be (re-)assessed. Informing the patient about possible relapses and deteriorations and how to deal with them should be also part of the treatment regimen.

DISCUSSION

Physical modalities and rehabilitation interventions should be used in out-patient rehabilitation setting for the treatment of Long-COVID. In this regard, it is also important to take into account and treat serious complications after the disease, such as post-intensive care syndrome. Due to the rapid evolution of the knowledge a frequent review of scientific papers and recommendations should be conducted. High-quality intervention studies are necessary to achieve greater evidence in this field.

Changing Face of Inflammatory Activation in Complex Coronary Artery Disease during the COVID-19 Pandemic

INTRODUCTION

The COVID-19 pandemic has changed the immunological status of the population, indicating increased activation. The aim of the study was to compare the degree of inflammatory activation in patients admitted for surgical revascularization in the period before and during the COVID-19 pandemic.

MATERIALS AND METHODS

This retrospective analysis included an analysis of inflammatory activation assessed on the basis of whole blood counts in 533 patients (435 (82%) male and 98 (18%) female) with a median age of 66 (61-71) years who underwent surgical revascularization, including 343 and 190 patients operated on in 2018 and 2022, respectively.

RESULTS

The compared groups were matched by propensity score matching analysis, obtaining 190 patients in each group. Significantly higher values of preoperative monocyte count (p = 0.015), monocyte-to-lymphocyte ratio (p = 0.004) and systemic inflammatory response index (p = 0.022) were found in the during-COVID subgroup. The perioperative and 12-month mortality rates were comparable, with 1% (n = 4) in 2018 vs. 1% (n = 2) in 2022 (p = 0.911), and 5.6 % (n = 11 patients) vs. 7% (n = 13 patients) (p = 0.413), in the pre-COVID and during-COVID subgroups, respectively.

CONCLUSIONS

Simple whole blood analysis in patients with complex coronary artery disease performed before and during the COVID-19 pandemic indicates excessive inflammatory activation. However, the immune variation did not interfere with one-year mortality rate after surgical revascularization.

Pre-pandemic autonomic function as a predictor of the COVID clinical course in young adults

Long coronavirus disease (COVID) is emerging as a common clinical entity in the current era. Autonomic dysfunction is one of the frequently reported post-COVID complications. We hypothesize a bi-directional relationship between the autonomic function and the COVID course. This postulation has been inadequately addressed in the literature. A retrospective cohort (pre and post-comparison) study was conducted on 30 young adults whose pre-COVID autonomic function test results were available. They were divided into case and control groups based on whether they tested reverse transcription polymerase chain reaction positive for COVID-19. Autonomic function tests were performed in both the case and control groups. COVID infection in healthy young adults shifts the sympatho-vagal balance from the pre-disease state. Postural orthostatic tachycardia syndrome was present in 35% of the COVID-affected group. COVID course parameters were found to be associated with parasympathetic reactivity and the baroreflex function. Baseline autonomic function (parasympathetic reactivity represented by Δ heart rate changes during deep breathing and 30:15 ratio during lying-to-standing test) was also associated with the COVID course, the post-COVID symptoms and the post-COVID autonomic function profile. Additionally, multiple regression analysis found that the baseline parasympathetic reactivity was a very important determinant of the clinical course of COVID, the post-COVID symptoms and the post-COVID autonomic profile. Sympatho-vagal balance shifts to parasympathetic withdrawal with sympathetic predominance due to COVID infection in healthy young adults. There is a bi-directional relationship between the autonomic function and the COVID course.

Long COVID: a review and proposed visualization of the complexity of long COVID

Post-Acute Sequelae of Severe Acute Respiratory Syndrome Coronavirus - 2 (SARS-CoV-2) infection, or Long COVID, is a prevailing second pandemic with nearly 100 million affected individuals globally and counting. We propose a visual description of the complexity of Long COVID and its pathogenesis that can be used by researchers, clinicians, and public health officials to guide the global effort toward an improved understanding of Long COVID and the eventual mechanism-based provision of care to afflicted patients. The proposed visualization or framework for Long COVID should be an evidence-based, dynamic, modular, and systems-level approach to the condition. Furthermore, with further research such a framework could establish the strength of the relationships between pre-existing conditions (or risk factors), biological mechanisms, and resulting clinical phenotypes and outcomes of Long COVID. Notwithstanding the significant contribution that disparities in access to care and social determinants of health have on outcomes and disease course of long COVID, our model focuses primarily on biological mechanisms. Accordingly, the proposed visualization sets out to guide scientific, clinical, and public health efforts to better understand and abrogate the health burden imposed by long COVID.

Long COVID: pathophysiological factors and abnormalities of coagulation

Acute COVID-19 infection is followed by prolonged symptoms in approximately one in ten cases: known as Long COVID. The disease affects ~65 million individuals worldwide. Many pathophysiological processes appear to underlie Long COVID, including viral factors (persistence, reactivation, and bacteriophagic action of SARS CoV-2); host factors (chronic inflammation, metabolic and endocrine dysregulation, immune dysregulation, and autoimmunity); and downstream impacts (tissue damage from the initial infection, tissue hypoxia, host dysbiosis, and autonomic nervous system dysfunction). These mechanisms culminate in the long-term persistence of the disorder characterized by a thrombotic endothelialitis, endothelial inflammation, hyperactivated platelets, and fibrinaloid microclots. These abnormalities of blood vessels and coagulation affect every organ system and represent a unifying pathway for the various symptoms of Long COVID.

Long-Term Impact of COVID-19 on Heart Rate Variability: A Systematic Review of Observational Studies

Coronavirus disease 2019 (COVID-19) sequelae (or long COVID) has become a clinically significant concern. Several studies have reported the relationship between heart rate variability (HRV) parameters and COVID-19. This review investigates the long-term association between COVID-19 and HRV parameters. Four electronic databases were searched up to 29 July 2022. We included observational studies comparing HRV parameters (measurement durations: 1 min or more) in participants with and without a history of COVID-19. We used assessment tools developed by the National Heart, Lung, and Blood Institute group to evaluate the methodological quality of included studies. Eleven cross-sectional studies compared HRV parameters in individuals who recovered from acute COVID-19 infection to controls (n = 2197). Most studies reported standard deviation of normal-to-normal intervals (SDNN) and root mean square of the successive differences. The methodological quality of the included studies was not optimal. The included studies generally found decreased SDNN and parasympathetic activity in post-COVID-19 individuals. Compared to controls, decreases in SDNN were observed in individuals who recovered from COVID-19 or had long COVID. Most of the included studies emphasized parasympathetic inhibition in post-COVID-19 conditions. Due to the methodological limitations of measuring HRV parameters, the findings should be further validated by robust prospective longitudinal studies.

A review of cytokine-based pathophysiology of Long COVID symptoms

The Long COVID/Post Acute Sequelae of COVID-19 (PASC) group includes patients with initial mild-to-moderate symptoms during the acute phase of the illness, in whom recovery is prolonged, or new symptoms are developed over months. Here, we propose a description of the pathophysiology of the Long COVID presentation based on inflammatory cytokine cascades and the p38 MAP kinase signaling pathways that regulate cytokine production. In this model, the SARS-CoV-2 viral infection is hypothesized to trigger a dysregulated peripheral immune system activation with subsequent cytokine release. Chronic low-grade inflammation leads to dysregulated brain microglia with an exaggerated release of central cytokines, producing neuroinflammation. Immunothrombosis linked to chronic inflammation with microclot formation leads to decreased tissue perfusion and ischemia. Intermittent fatigue, Post Exertional Malaise (PEM), CNS symptoms with "brain fog," arthralgias, paresthesias, dysautonomia, and GI and ophthalmic problems can consequently arise as result of the elevated peripheral and central cytokines. There are abundant similarities between symptoms in Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). DNA polymorphisms and viral-induced epigenetic changes to cytokine gene expression may lead to chronic inflammation in Long COVID patients, predisposing some to develop autoimmunity, which may be the gateway to ME/CFS.

COVID-19 Induced Postural Orthostatic Tachycardia Syndrome (POTS): A Review

POTS (Postural Orthostatic Tachycardia Syndrome) is a multisystem disorder characterized by the abnormal autonomic response to an upright posture, causing orthostatic intolerance and excessive tachycardia without hypotension. Recent reports suggest that a significant percentage of COVID-19 survivors develop POTS within 6 to 8 months of infection. Prominent symptoms of POTS include fatigue, orthostatic intolerance, tachycardia, and cognitive impairment. The exact mechanisms of post-COVID-19 POTS are unclear. Still, different hypotheses have been given, including autoantibody production against autonomic nerve fibers, direct toxic effects of SARS-CoV-2, or sympathetic nervous system stimulation secondary to infection. Physicians should have a high suspicion of POTS in COVID-19 survival when presented with symptoms of autonomic dysfunction and should conduct diagnostic tests like the Tilt table and others to confirm it. The management of COVID-19-related POTS requires a comprehensive approach. Most patients respond to initial non-pharmacological options, but when the symptoms become more severe and they do not respond to the non-pharmacological approach, pharmacological options are considered. We have limited understanding and knowledge of post-COVID-19 POTS, and further research is warranted to improve our understanding and formulate a better management plan.

Headache in long COVID as disabling condition: A clinical approach

Background and purpose

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can exacerbate previous headache disorders or change the type of pain experienced from headaches. This study aimed to investigate the clinical features of Long COVID headaches.

Method

This was a cross-sectional, descriptive, and analytical observational study that included 102 patients (with previous headache, n = 50; without previous headache, n = 52) with long COVID and headache complaints. The Migraine Disability Assessment Test and Visual Analog Pain Scale were used to collect participants' headache data according to a standardized protocol.

Results

The patients in this study who reported experiencing headaches before COVID-19 had longer headache duration in the long COVID phase than that in the pre-long COVID phase (p = 0.031), exhibited partial improvement in headache symptoms with analgesics (p = 0.045), and had a duration of long COVID of <1 year (p = 0.030). Patients with moderate or severe disability and those classified as having severe headaches in the long COVID phase were highly likely to develop chronic headaches. Hospital admission [odds ratio (OR) = 3.0082; 95% confidence interval (95% CI): 1.10-8.26], back pain (OR = 4.0017; 95% CI: 1.13-14.17), insomnia (OR = 3.1339; 95% CI: 1.39-7.06), and paraesthesia (OR = 2.7600; 95% CI: 1.20-6.33) were associated with headache in these patients.

Conclusion

Headache is a disabling condition in patients with long COVID-19, exacerbating the conditions of those with headaches prior to contracting COVID-19.

Long COVID prevalence and physiology-centered risks: population-based study in Ukraine

AIM

Multifaceted long COVID caused by SARS-COV-2 affects all populations in the World and takes priority over any other research topics for health care. The purpose of study is to identify physiology-centered risks, prevalence, symptoms and laboratory findings in patients with long COVID in Ukraine.

METHODS

A prospective, cohort study was carried out on 332 patients with long COVID after 4 weeks and more after acute infection COVID-19 from Jul 1, 2021, to Jul 1, 2022. Physiology-centered risks related to age, gender, body mass index (BMI), marital status and educational capacity, smoking, lifestyle, physical activity, and laboratory findings (before disease), and symptom distribution were analyzed.

RESULTS

The cohort for the study consisted of 166 females and 107 males (mean age = 42; including young 18 (5.4%) and middle- and old-aged adults 314 (96.4%)). Increased BMI was in 61%, and less physical activity-65%. There were 4 clusters of symptoms related to physical, neurocognitive, pulmonary, and pain conditions. 95% of participants had ≥ 3 symptoms. The most common symptoms were fatigue (90%), muscular pain (85%), anosmia (70%), hair loss (70%), sleep disorders (70%), dyspnea (30%), and brain fog (25%). Among laboratory finding increased CRP (92.6%) and fibrinogen (82.7%) dominated. There are no differences between hospitalized and non-hospitalized patients in distribution symptoms.

CONCLUSIONS

The prevalence of long COVID is 23%, and its physiology-centered risk factors are related to age more 38 years, female sex, unhealthy lifestyle, increased BMI, and increased inflammatory markers during COVID-19. The most common symptoms are associated with neurocognitive and pain clusters.

Patients' lived experience and reflections on long COVID: an interpretive phenomenological analysis within an integrated adult primary care psychology NHS service

BACKGROUND

Long Covid is an unknown illness which has been shown to affect sufferers regardless of mild initial COVID-19 or age. There is still a lot unknown about long COVID illness. There has been a call to understand this illness not only from a professional standpoint but also through the lived experience of patients. Patient reported outcomes through lived experience research is one such angle. To date, no research has explored the overall lived experiences and long COVID illness trajectory perspectives of the patients. This study aimed to gather patient reported outcomes of their long COVID through lived experience research. It recruited adult participants aged 18-years and over who had been referred to a primary care integrated psychology service. The study employed qualitative research using semi-structured interviews and Interpretive Phenomenological Analysis methodology.

RESULTS

A total of eighteen participants completed the study. From their lived experiences, the participants uncovered the varied symptoms of long COVID. They also uncovered their lived progression of living with an unknown chronic illness. Common themes included uncertainty, mental and social impacts, and the processes of self-advocacy, mastering their symptoms, subjective recovery and future coping.

CONCLUSION

This study uncovered the lived experience of long COVID in participants. The results from this study uncovered the lived subjective biopsychosocial experiences of long COVID chronic illness. Traditionally, patients receive care and recommendations from healthcare professionals. However, as long COVID is a new illness, this care model was limited. The participants in the current study described being left with a sense of uncertainty and role confusion. However, participants were able to realize their locus of control over their long COVID illness progression. This illustrates that patients have the resources to uncover the unknowns of this new illness which could inform clinical practice and further research. This suggests that that long COVID needs to be approached from a biopsychosocial perspective which emphasises patient involvement.

The potential role of SARS‐CoV‐2 infection in acute coronary syndrome and type 2 myocardial infarction (T2MI): Intertwining spread

Coronavirus disease 2019 (COVID‐19) is a novel pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). It has been shown that SARS‐CoV‐2 infection‐induced inflammatory and oxidative stress and associated endothelial dysfunction may lead to the development of acute coronary syndrome (ACS). Therefore, this review aimed to ascertain the link between severe SARS‐CoV‐2 infection and ACS. ACS is a spectrum of acute myocardial ischemia due to a sudden decrease in coronary blood flow, ranging from unstable angina to myocardial infarction (MI). Primary or type 1 MI (T1MI) is mainly caused by coronary plaque rupture and/or erosion with subsequent occlusive thrombosis. Secondary or type 2 MI (T2MI) is due to cardiac and systemic disorders without acute coronary atherothrombotic disruption. Acute SARS‐CoV‐2 infection is linked with the development of nonobstructive coronary disorders such as coronary vasospasm, dilated cardiomyopathy, myocardial fibrosis, and myocarditis. Furthermore, SARS‐CoV‐2 infection is associated with systemic inflammation that might affect coronary atherosclerotic plaque stability through augmentation of cardiac preload and afterload. Nevertheless, major coronary vessels with atherosclerotic plaques develop minor inflammation during COVID‐19 since coronary arteries are not initially and primarily targeted by SARS‐CoV‐2 due to low expression of angiotensin‐converting enzyme 2 in coronary vessels. In conclusion, SARS‐CoV‐2 infection through hypercytokinemia, direct cardiomyocyte injury, and dysregulation of the renin‐angiotensin system may aggravate underlying ACS or cause new‐onset T2MI. As well, arrhythmias induced by anti‐COVID‐19 medications could worsen underlying ACS.

An Unusual Case of Blackout in a COVID-19 Patient: COVID-19 Brain Fog

This case report highlights a unique case of brain fog in a COVID-19 patient suggesting COVID-19's neurotropic nature. COVID-19 is associated with a long-COVID syndrome that presents with cognitive decline and fatigue. Recent studies show the emergence of a novel syndrome known as post-acute COVID syndrome or long COVID, which constitutes a variety of symptoms that continue for four weeks following the onset of a COVID-19 diagnosis. Numerous post-COVID patients experience both short and long-lasting symptoms affecting several organs, including the brain, which includes being unconscious, bradyphrenia, or amnesia. This long COVID status comprises of "brain fog", which, coupled with neuro-cognitive effects, has a significant role in prolonging the recovery phase. The pathogenesis of brain fog is currently unknown. One of the leading causes might be the involvement of neuroinflammation due to mast cells stimulated by pathogenic and stress stimuli. This in turn, triggers the release of mediators that activate microglia, causing inflammation in the hypothalamus. Its ability to invade the nervous system through trans-neural or hematogenous mechanisms is possibly the chief cause behind the presenting symptoms. This case report highlights a unique case of brain fog in a COVID-19 patient suggesting COVID-19's neurotropic nature and how it may lead to neurologic complications such as meningitis, encephalitis, and Guillain-Barré syndrome.

Autoimmunity in Long Covid and POTS

Orthostatic intolerance and other autonomic dysfunction syndromes are emerging as distinct symptom clusters in Long Covid. Often accompanying these are common, multi-system constitutional features such as fatigue, malaise and skin rashes which can signify generalized immune dysregulation. At the same time, multiple autoantibodies are identified in both Covid-related autonomic disorders and non-Covid autonomic disorders, implying a possible underlying autoimmune pathology. The lack of specificity of these findings precludes direct interpretations of cause and association, but their prevalence with its supporting evidence is compelling.

Post-exertional malaise among people with long COVID compared to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

BACKGROUND

Long COVID describes a condition with symptoms that linger for months to years following acute COVID-19. Many of these Long COVID symptoms are like those experienced by patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

OBJECTIVE

We wanted to determine if people with Long COVID experienced post-exertional malaise (PEM), the hallmark symptom of ME/CFS, and if so, how it compared to PEM experienced by patients with ME/CFS.

METHODS

A questionnaire that asked about the domains of PEM including triggers, experience, recovery, and prevention was administered to 80 people seeking care for Long COVID at Bateman Horne Center. Their responses were compared to responses about PEM given by 151 patients with ME/CFS using chi-square tests of independence.

RESULTS

All but one Long COVID respondent reported having PEM. There were many significant differences in the types of PEM triggers, symptoms experienced during PEM, and ways to recover and prevent PEM between Long COVID and ME/CFS. Similarities between Long COVID and ME/CFS included low and medium physical and cognitive exertion to trigger PEM, symptoms of fatigue, pain, immune reaction, neurologic, orthostatic intolerance, and gastrointestinal symptoms during PEM, rest to recover from PEM, and pacing to prevent PEM.

CONCLUSION

People with Long COVID experience PEM. There were significant differences in PEM experienced by people with Long COVID compared to patients with ME/CFS. This may be due to the newness of Long COVID, not knowing what exertional intolerance is or how to manage it.

Prognosis value of pupillometry in COVID-19 patients admitted in intensive care unit

INTRODUCTION

ICU patients with SARS-CoV-2-related pneumonia are at risk to develop a central dysautonomia which can contribute to mortality and respiratory failure. The pupillary size and its reactivity to light are controlled by the autonomic nervous system. Pupillometry parameters (PP) allow to predict outcomes in various acute brain injuries. We aim at assessing the most predictive PP of in-hospital mortality and the need for invasive mechanical ventilation (IV).

MATERIAL AND METHODS

We led a prospective, two centers, observational study. We recruited adult patients admitted to ICU for a severe SARS-CoV-2 related pneumonia between April and August 2020. The pupillometry was performed at admission including the measurement of baseline pupillary diameter (PD), PD variations (PDV), pupillary constriction velocity (PCV) and latency (PDL).

RESULTS

Fifty patients, 90 % males, aged 66 (60-70) years were included. Seven (14 %) patients died in hospital. The baseline PD (4.1 mm [3.5; 4.8] vs 2.6 mm [2.4; 4.0], P = 0.009), PDV (33 % [27; 39] vs 25 % [15; 36], P = 0.03) and PCV (3.5 mm.s^-1 [2.8; 4.4] vs 2.0 mm.s^-1 [1.9; 3.8], P = 0.02) were significantly lower in patients who will die. A PD value <2.75 mm was the most predictive parameter of in-hospital mortality, with an AUC = 0.81, CI 95 % [0.63; 0.99]. Twenty-four (48 %) patients required IV. PD and PDV were significantly lower in patients who were intubated (3.5 mm [2.8; 4.4] vs 4.2 mm [3.9; 5.2], P = 0.03; 28 % [25; 36 %] vs 35 % [32; 40], P = 0.049, respectively).

CONCLUSIONS

A reduced baseline PD is associated with bad outcomes in COVID-19 patients admitted in ICU. It is likely to reflect a brainstem autonomic dysfunction.

Investigating the possible mechanisms of autonomic dysfunction post-COVID-19

Patients with long COVID suffer from many neurological manifestations that persist for 3 months following infection by SARS-CoV-2. Autonomic dysfunction (AD) or dysautonomia is one complication of long COVID that causes patients to experience fatigue, dizziness, syncope, dyspnea, orthostatic intolerance, nausea, vomiting, and heart palpitations. The pathophysiology behind AD onset post-COVID is largely unknown. As such, this review aims to highlight the potential mechanisms by which AD occurs in patients with long COVID. The first proposed mechanism includes the direct invasion of the hypothalamus or the medulla by SARS-CoV-2. Entry to these autonomic centers may occur through the neuronal or hematogenous routes. However, evidence so far indicates that neurological manifestations such as AD are caused indirectly. Another mechanism is autoimmunity whereby autoantibodies against different receptors and glycoproteins expressed on cellular membranes are produced. Additionally, persistent inflammation and hypoxia can work separately or together to promote sympathetic overactivation in a bidirectional interaction. Renin-angiotensin system imbalance can also drive AD in long COVID through the downregulation of relevant receptors and formation of autoantibodies. Understanding the pathophysiology of AD post-COVID-19 may help provide early diagnosis and better therapy for patients.

A patient who recovered from post-COVID myalgic encephalomyelitis/chronic fatigue syndrome: a case report

BACKGROUND

Some patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) complain of persistent fatigue, dyspnea, pain, and cognitive dysfunction. These symptoms are often described as "long COVID". Whether a patient with long COVID might develop myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is of interest, as is the treatment and management of ME/CFS in a post-COVID patient. Here I report a patient, who, after an infection with SARS-CoV-2, developed ME/CFS and recovered after treatment.

CASE PRESENTATION

The patient was a previously healthy 55-year-old woman who worked as a nurse and became ill with COVID-19 pneumonia. She then presented with severe fatigue, post-exertional malaise, dyspnea, pain, cognitive dysfunction, tachycardia, and exacerbation of fatigue on physical exertion, which persisted for more than 6 months after her recovery from COVID-19 pneumonia. She was bedridden for more than half of each day. The patient was treated from multiple perspectives, which included (1) instructions on eating habits and supplements; (2) cognitive and behavioral modifications for coping with physical, emotional, and cognitive fatigue; (3) instructions on conditioning exercises to improve deconditioning due to fatigue and dyspnea; and (4) pharmacotherapy with amitriptyline and hochuekkito, a Japanese herbal (Kampo) medicine. The patient made a complete recovery after completing the prescribed regimen and was able to return to work as a nurse.

CONCLUSIONS

To the best of my knowledge, this is the first detailed report on a patient infected with SARS-CoV-2 followed by long COVID with the signs/symptoms of ME/CFS who recovered after treatment. I hope this case report will be helpful to health care practitioners by its presentation of some of the therapeutic options for alleviating disabling signs/symptoms in patients with post-COVID ME/CFS.

[Clinical and neurophysiological parameters in patients with epilepsy in the long-term period after COVID-19]

OBJECTIVE

Clinical and psychophysiological assessment of the dynamics of the condition of patients with epilepsy in 4-6 months after the coronavirus infection.

MATERIAL AND METHODS

An open controlled prospective comparative outpatient clinical and physiological study of patients diagnosed with epilepsy after suffering from COVID-19 (after 4-6 months) of moderate severity (n=16), patients diagnosed with epilepsy who did not suffer from COVID-19 (n=7), a control group (n=11) after confirmed COVID-19 (after 4-6 months). All groups were in the age range 23 to 50 years. Clinical/neurological and somatic research included: anamnesis, neurological examination, questioning, ECG, EEG, clinical and psychometric tests.

RESULTS

There was an increase in the representation of epileptiform activity in the background EEG and more pronounced activity in provoking samples compared with background recording in 26.5% of patients who had suffered COVID-19 compared with the group of patients with epilepsy who had not suffered COVID-19. The detection of rare epileptic seizures in 18.8% of cases in the group of epilepsy patients, who underwent COVID-19, indicates an increase in epileptogenesis and a decrease in therapeutic control over seizures. At the same time, 87.5% of patients in this group showed a statistically significant increase in the influence of the sympathetic nervous system on the regulation of heart rhythm and an increase in anxiety and depression.

CONCLUSION

The results can complement the understanding of the neuropsychiatric status of patients with epilepsy after COVID-19, which provides prerequisites for the development of optimal recovery directions in the rehabilitation period to maintain drug remission of epilepsy and reduce the possible progression of the disease.

The Adaptive Force as a Potential Biomechanical Parameter in the Recovery Process of Patients with Long COVID

Long COVID patients show symptoms, such as fatigue, muscle weakness and pain. Adequate diagnostics are still lacking. Investigating muscle function might be a beneficial approach. The holding capacity (maximal isometric Adaptive Force; AFiso_max) was previously suggested to be especially sensitive for impairments. This longitudinal, non-clinical study aimed to investigate the AF in long COVID patients and their recovery process. AF parameters of elbow and hip flexors were assessed in 17 patients at three time points (pre: long COVID state, post: immediately after first treatment, end: recovery) by an objectified manual muscle test. The tester applied an increasing force on the limb of the patient, who had to resist isometrically for as long as possible. The intensity of 13 common symptoms were queried. At pre, patients started to lengthen their muscles at ~50% of the maximal AF (AF_max), which was then reached during eccentric motion, indicating unstable adaptation. At post and end, AFiso_max increased significantly to ~99% and 100% of AF_max, respectively, reflecting stable adaptation. AF_max was statistically similar for all three time points. Symptom intensity decreased significantly from pre to end. The findings revealed a substantially impaired maximal holding capacity in long COVID patients, which returned to normal function with substantial health improvement. AFiso_max might be a suitable sensitive functional parameter to assess long COVID patients and to support therapy process.

Risk factors for impaired respiratory function post COVID-19: A prospective cohort study of nonhospitalized and hospitalized patients

BACKGROUND

Severe COVID-19 increases the risk for long-term respiratory impairment, but data after mild COVID-19 are scarce. Our aims were to determine risk factors for reduced respiratory function 3-6 months after COVID-19 infection and to investigate if reduced respiratory function would relate to impairment of exercise performance and breathlessness.

METHODS

Patients with COVID-19 were enrolled at the University Hospitals of Umeå and Örebro, and Karlstad Central Hospital, Sweden. Disease severity was defined as mild (nonhospitalized), moderate (hospitalized with or without oxygen treatment), and severe (intensive care). Spirometry, including diffusion capacity (DL_CO ), was performed 3-6 months after hospital discharge or study enrollment (for nonhospitalized patients). Breathlessness (defined as ≥1 according to the modified Medical Research Council scale) and functional exercise capacity (1-min sit-to-stand test; 1-MSTST) were assessed.

RESULTS

Between April 2020 and May 2021, 337 patients were enrolled in the study. Forced vital capacity and DL_CO were significantly lower in patients with severe COVID-19. Among hospitalized patients, 20% had reduced DL_CO , versus 4% in nonhospitalized. Breathlessness was found in 40.6% of the participants and was associated with impaired DL_CO . A pathological desaturation or heart rate response was observed in 17% of participants during the 1-MSTST. However, this response was not associated with reduced DL_CO .

CONCLUSION

Reduced DL_CO was the major respiratory impairment 3-6 months following COVID-19, with hospitalization as the most important risk factor. The lack of association between impaired DL_CO and pathological physiological responses to exertion suggests that these physiological responses are not primarily related to decreased lung function.

Association of Heart Rate Variability with Pulmonary Function Impairment and Symptomatology Post-COVID-19 Hospitalization

The persistence of symptoms beyond three months after COVID-19 infection, often referred to as post-COVID-19 condition (PCC), is commonly experienced. It is hypothesized that PCC results from autonomic dysfunction with decreased vagal nerve activity, which can be indexed by low heart rate variability (HRV). The aim of this study was to assess the association of HRV upon admission with pulmonary function impairment and the number of reported symptoms beyond three months after initial hospitalization for COVID-19 between February and December 2020. Follow-up took place three to five months after discharge and included pulmonary function tests and the assessment of persistent symptoms. HRV analysis was performed on one 10 s electrocardiogram obtained upon admission. Analyses were performed using multivariable and multinomial logistic regression models. Among 171 patients who received follow-up, and with an electrocardiogram at admission, decreased diffusion capacity of the lung for carbon monoxide (DLCO) (41%) was most frequently found. After a median of 119 days (IQR 101-141), 81% of the participants reported at least one symptom. HRV was not associated with pulmonary function impairment or persistent symptoms three to five months after hospitalization for COVID-19.

Organ and cell-specific biomarkers of Long-COVID identified with targeted proteomics and machine learning

BACKGROUND

Survivors of acute COVID-19 often suffer prolonged, diffuse symptoms post-infection, referred to as "Long-COVID". A lack of Long-COVID biomarkers and pathophysiological mechanisms limits effective diagnosis, treatment and disease surveillance. We performed targeted proteomics and machine learning analyses to identify novel blood biomarkers of Long-COVID.

METHODS

A case-control study comparing the expression of 2925 unique blood proteins in Long-COVID outpatients versus COVID-19 inpatients and healthy control subjects. Targeted proteomics was accomplished with proximity extension assays, and machine learning was used to identify the most important proteins for identifying Long-COVID patients. Organ system and cell type expression patterns were identified with Natural Language Processing (NLP) of the UniProt Knowledgebase.

RESULTS

Machine learning analysis identified 119 relevant proteins for differentiating Long-COVID outpatients (Bonferonni corrected P < 0.01). Protein combinations were narrowed down to two optimal models, with nine and five proteins each, and with both having excellent sensitivity and specificity for Long-COVID status (AUC = 1.00, F1 = 1.00). NLP expression analysis highlighted the diffuse organ system involvement in Long-COVID, as well as the involved cell types, including leukocytes and platelets, as key components associated with Long-COVID.

CONCLUSIONS

Proteomic analysis of plasma from Long-COVID patients identified 119 highly relevant proteins and two optimal models with nine and five proteins, respectively. The identified proteins reflected widespread organ and cell type expression. Optimal protein models, as well as individual proteins, hold the potential for accurate diagnosis of Long-COVID and targeted therapeutics.

A machine learning approach identifies distinct early-symptom cluster phenotypes which correlate with hospitalization, failure to return to activities, and prolonged COVID-19 symptoms

BACKGROUND

Accurate COVID-19 prognosis is a critical aspect of acute and long-term clinical management. We identified discrete clusters of early stage-symptoms which may delineate groups with distinct disease severity phenotypes, including risk of developing long-term symptoms and associated inflammatory profiles.

METHODS

1,273 SARS-CoV-2 positive U.S. Military Health System beneficiaries with quantitative symptom scores (FLU-PRO Plus) were included in this analysis. We employed machine-learning approaches to identify symptom clusters and compared risk of hospitalization, long-term symptoms, as well as peak CRP and IL-6 concentrations.

RESULTS

We identified three distinct clusters of participants based on their FLU-PRO Plus symptoms: cluster 1 ("Nasal cluster") is highly correlated with reporting runny/stuffy nose and sneezing, cluster 2 ("Sensory cluster") is highly correlated with loss of smell or taste, and cluster 3 ("Respiratory/Systemic cluster") is highly correlated with the respiratory (cough, trouble breathing, among others) and systemic (body aches, chills, among others) domain symptoms. Participants in the Respiratory/Systemic cluster were twice as likely as those in the Nasal cluster to have been hospitalized, and 1.5 times as likely to report that they had not returned-to-activities, which remained significant after controlling for confounding covariates (P < 0.01). Respiratory/Systemic and Sensory clusters were more likely to have symptoms at six-months post-symptom-onset (P = 0.03). We observed higher peak CRP and IL-6 in the Respiratory/Systemic cluster (P < 0.01).

CONCLUSIONS

We identified early symptom profiles potentially associated with hospitalization, return-to-activities, long-term symptoms, and inflammatory profiles. These findings may assist in patient prognosis, including prediction of long COVID risk.

Individuals with a previous symptomatic COVID-19 infection have altered heart rate and blood pressure variability during acute exercise

Introduction: As the number of COVID-19 cases begin to diminish it is important to turn our attention to any long-term issues that may be associated with a prior infection. Cardiovascular defects have been noted following prior SARS-CoV-2 infections. However, less is known about how a previous infection alters the cardiovascular response to exercise. Further, differences may exist during exercise between previously SARS-CoV-2 positive individuals who had symptoms (symptomatic) relative to those who did not have symptoms (asymptomatic). We hypothesized that previously symptomatic (S) COVID-19 recoveries have an altered cardiovascular response to acute exercise relative to both control (CON; never infected), and previously COVID-19 positive asymptomatic (AS) individuals. Methods: Twenty-seven subjects (CON = 9; AS = 9; S = 9) underwent 30 min of submaximal treadmill exercise. During exercise, blood pressure was recorded on the brachial artery every 5 min and 3-lead electrocardiography was measured continuously. Indirect indicators of autonomic nervous system health: heart rate variability and blood pressure variability were measured during each session. Baseline mean arterial pressure (MAP) was taken prior to exercise in seated, standing and supine positions. Results: Blood pressure was similar (p > 0.05) amongst all three groups. There were no differences between average heart rate (HR; CON = 104 ± 4 BPM vs AS = 118 ± 6 BPM vs. S = 112 ± 3 BPM), mean arterial pressure (MAP; CON = 108 ± 4 mmHg vs. AS = 105 ± 13 mmHg vs. S = 108 ± 7 mmHg) or oxygen consumption (VO₂) between groups during a bout of exercise. However, the standard deviation of the inter beat intervals of normal sinus beats, a measure of heart rate variability (HRV) (CON = 138 ± 2.8 m vs. AS = 156 ± 6 m vs. S = 77.7 ± 11 m; p < 0.05) and blood pressure variability (BPV; CON = 5.18 ± 1.1 vs. AS = 12.1 ± 0.88 mmHg vs. S = 10.2 ± 10.7 mmHg; p < 0.05) were different in our S group. Further, when HRV was assessed in the frequency domain the very low frequency was different during exercise in the S group relative to the other groups. Discussion: Collectively, these data suggest that a previous symptomatic SARS-CoV-2 infection may alter heart rate and blood pressure regulation during exercise.

Hyaluronan in the pathogenesis of acute and post-acute COVID-19 infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recently emerged as the cause of a global pandemic. Infection with SARS-CoV-2 can result in COVID-19 with both acute and chronic disease manifestations that continue to impact many patients long after the resolution of viral replication. There is therefore great interest in understanding the host factors that contribute to COVID-19 pathogenesis. In this review, we address the role of hyaluronan (HA), an extracellular matrix polymer with roles in inflammation and cellular metabolism, in COVID-19 and critically evaluate the hypothesis that HA promotes COVID-19 pathogenesis. We first provide a brief overview of COVID-19 infection. Then we briefly summarize the known roles of HA in airway inflammation and immunity. We then address what is known about HA and the pathogenesis of COVID-19 acute respiratory distress syndrome (COVID-19 ARDS). Next, we examine potential roles for HA in post-acute SARS-CoV-2 infection (PASC), also known as "long COVID" as well as in COVID-associated fibrosis. Finally, we discuss the potential therapeutics that target HA as a means to treat COVID-19, including the repurposed drug hymecromone (4-methylumbelliferone). We conclude that HA is a promising potential therapeutic target for the treatment of COVID-19.

Long-COVID post-viral chronic fatigue and affective symptoms are associated with oxidative damage, lowered antioxidant defenses and inflammation: a proof of concept and mechanism study

The immune-inflammatory response during the acute phase of COVID-19, as assessed using peak body temperature (PBT) and peripheral oxygen saturation (SpO2), predicts the severity of chronic fatigue, depression and anxiety symptoms 3-4 months later. The present study was performed to examine the effects of SpO2 and PBT during acute infection on immune, oxidative and nitrosative stress (IO&NS) pathways and neuropsychiatric symptoms of Long COVID. This study assayed SpO2 and PBT during acute COVID-19, and C-reactive protein (CRP), malondialdehyde (MDA), protein carbonyls (PCs), myeloperoxidase (MPO), nitric oxide (NO), zinc, and glutathione peroxidase (Gpx) in 120 Long COVID individuals and 36 controls. Cluster analysis showed that 31.7% of the Long COVID patients had severe abnormalities in SpO2, body temperature, increased oxidative toxicity (OSTOX) and lowered antioxidant defenses (ANTIOX), and increased total Hamilton Depression (HAMD) and Anxiety (HAMA) and Fibromylagia-Fatigue (FF) scores. Around 60% of the variance in the neuropsychiatric symptoms of Long COVID (a factor extracted from HAMD, HAMA and FF scores) was explained by OSTOX/ANTIOX ratio, PBT and SpO2. Increased PBT predicted increased CRP and lowered ANTIOX and zinc levels, while lowered SpO2 predicted lowered Gpx and increased NO production. Lowered SpO2 strongly predicts OSTOX/ANTIOX during Long COVID. In conclusion, the impact of acute COVID-19 on the symptoms of Long COVID is partly mediated by OSTOX/ANTIOX, especially lowered Gpx and zinc, increased MPO and NO production and lipid peroxidation-associated aldehyde formation. The results suggest that post-viral somatic and mental symptoms have a neuroimmune and neuro-oxidative origin.

Neurological symptoms and comorbidity profile of hospitalized patients with COVID-19

BACKGROUND

 The neurological manifestations in COVID-19 adversely impact acute illness and post-disease quality of life. Limited data exist regarding the association of neurological symptoms and comorbid individuals.

OBJECTIVE

 To assess neurological symptoms in hospitalized patients with acute COVID-19 and multicomorbidities.

METHODS

 Between June 2020 and July 2020, inpatients aged 18 or older, with laboratory-confirmed COVID-19, admitted to the Hospital São Paulo (Federal University of São Paulo), a tertiary referral center for high complexity cases, were questioned about neurological symptoms. The Composite Autonomic Symptom Score 31 (COMPASS-31) questionnaire was used. The data were analyzed as a whole and whether subjective olfactory dysfunction was present or not.

RESULTS

 The mean age of the sample was 55 ± 15.12 years, and 58 patients were male. The neurological symptoms were mostly xerostomia (71%), ageusia/hypogeusia (50%), orthostatic intolerance (49%), anosmia/hyposmia (44%), myalgia (31%), dizziness (24%), xerophthalmia (20%), impaired consciousness (18%), and headache (16%). Furthermore, 91% of the patients had a premorbidity. The 44 patients with subjective olfactory dysfunction were more likely to have hypertension, diabetes, weakness, shortness of breath, ageusia/hypogeusia, dizziness, orthostatic intolerance, and xerophthalmia. The COMPASS-31 score was higher than that of previously published controls (14.85 ± 12.06 vs. 8.9 ± 8.7). The frequency of orthostatic intolerance was 49% in sample and 63.6% in those with subjective olfactory dysfunction (2.9-fold higher risk compared to those without).

CONCLUSION

 A total of 80% of inpatients with multimorbidity and acute COVID-19 had neurological symptoms. Chemical sense and autonomic symptoms stood out. Orthostatic intolerance occurred in around two-thirds of the patients with anosmia/hyposmia. Hypertension and diabetes were common, mainly in those with anosmia/hyposmia.

Neurological post-acute sequelae of SARS-CoV-2 infection

The novel coronavirus disease 19 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can have two phases: acute (generally 4 weeks after onset) and chronic (>4 weeks after onset). Both phases include a wide variety of signs and symptoms including neurological and psychiatric symptoms. The signs and symptoms that are considered sequelae of COVID-19 are termed post-COVID condition, long COVID-19, and post-acute sequelae of SARS-CoV-2 infection (PASC). PASC symptoms include fatigue, dyspnea, palpitation, dysosmia, subfever, hypertension, alopecia, sleep problems, loss of concentration, amnesia, numbness, pain, gastrointestinal symptoms, depression, and anxiety. Because the specific pathophysiology of PASC has not yet been clarified, there are no definite criteria of the condition, hence the World Health Organization's definition is quite broad. Consequently, it is difficult to correctly diagnose PASC. Approximately 50% of patients may show at least one PASC symptom up to 12 months after COVID-19 infection; however, the exact prevalence of PASC has not been determined. Despite extensive research in progress worldwide, there are currently no clear diagnostic methodologies or treatments for PASC. In this review, we discuss the currently available information on PASC and highlight the neurological sequelae of COVID-19 infection. Furthermore, we provide clinical suggestions for diagnosing and caring for patients with PASC based on our outpatient clinic experience.

The unpredictability of labile blood pressure: Afferent baroreflex failure in a critical patient with multiple thyroid surgeries and COVID-19 infection

The carotid sinus-arterial baroreflex is essential in maintaining blood pressure (BP) regulation. Afferent baroreflex failure (ABF) can present with labile changes in BP within seconds and can be secondary to neck surgery or radiation. We present here the first case, to our knowledge, of ABF precipitated by thyroidectomy, in a patient with active COVID-19 pneumonia, causing difficult control of severely labile BP in a critical care unit. Contributing factors included her critical illness state with upregulation of IL-6 leading to pituitary-adrenal axis alteration, her thyroidectomy further exacerbating autonomic dysfunction, as well as downregulation of ACE2 via COVID-19 infection. Management was achieved with a combination of midodrine and clonidine catered to specific BP thresholds. Additional research with a multidisciplinary approach is warranted to fully optimize the treatment of ABF in patients with neck surgery and or inflammatory conditions such as COVID-19.

European Working Group on SARS-CoV-2: Current Understanding, Unknowns, and Recommendations on the Neurological Complications of COVID-19

The emergence of COVID-19 was rapidly followed by infection and the deaths of millions of people across the globe. With much of the research and scientific advancement rightly focused on reducing the burden of severe and critical acute COVID-19 infection, the long-term effects endured by those who survived the acute infection has been previously overlooked. Now, an appreciation for the post-COVID-19 condition, including its neurological manifestations, is growing, although there remain many unknowns regarding the aetiology and risk factors of the condition, as well as how to effectively diagnose and treat it. Here, drawing upon the experiences and expertise of the clinicians and academics of the European working group on COVID-19, we have reviewed the current literature to provide a comprehensive overview of the neurological sequalae of the post-COVID-19 condition. In this review, we provide a summary of the neurological symptoms associated with the post-COVID-19 condition, before discussing the possible mechanisms which may underly and manifest these symptoms. Following this, we explore the risk factors for developing neurological symptoms as a result of COVID-19 and the post-COVID-19 condition, as well as how COVID-19 infection may itself be a risk factor for the development of neurological disease in the future. Lastly, we evaluate how the post-COVID condition could be accurately diagnosed and effectively treated, including examples of the current guidelines, clinical outcomes and tools that have been developed to aid in this process, as well as addressing the protection provided by COVID-19 vaccines against post-COVID-19 condition. Overall, this review provides a comprehensive overview of the neurological sequalae of the post-COVID-19 condition.

Autonomic Function Recovery and Physical Activity Levels in Post-COVID-19 Young Adults after Immunization: An Observational Follow-Up Case-Control Study

Coronavirus disease 2019 (COVID-19) has detrimental multi-system consequences. Symptoms may appear during the acute phase of infection, but the literature on long-term recovery of young adults after mild to moderate infection is lacking. Heart rate variability (HRV) allows for the observation of autonomic nervous system (ANS) modulation post-SARS-CoV-2 infection. Since physical activity (PA) can help improve ANS modulation, investigating factors that can influence HRV outcomes after COVID-19 is essential to advancements in care and intervention strategies. Clinicians may use this research to aid in the development of non-medication interventions. At baseline, 18 control (CT) and 20 post-COVID-19 (PCOV) participants were observed where general anamnesis was performed, followed by HRV and PA assessment. Thus, 10 CT and 7 PCOV subjects returned for follow-up (FU) evaluation 6 weeks after complete immunization (two doses) and assessments were repeated. Over the follow-up period, a decrease in sympathetic (SNS) activity (mean heart rate: p = 0.0024, CI = -24.67--3.26; SNS index: p = 0.0068, CI = -2.50--0.32) and increase in parasympathetic (PNS) activity (mean RR: p = 0.0097, CI = 33.72-225.51; PNS index: p = 0.0091, CI = -0.20-1.47) were observed. At follow-up, HRV was not different between groups (p > 0.05). Additionally, no differences were observed in PA between moments and groups. This study provides evidence of ANS recovery after SARS-CoV-2 insult in young adults over a follow-up period, independent of changes in PA.

Mechanisms, Effects, and Management of Neurological Complications of Post-Acute Sequelae of COVID-19 (NC-PASC)

With a growing number of patients entering the recovery phase following infection with SARS-CoV-2, understanding the long-term neurological consequences of the disease is important to their care. The neurological complications of post-acute sequelae of SARS-CoV-2 infection (NC-PASC) represent a myriad of symptoms including headaches, brain fog, numbness/tingling, and other neurological symptoms that many people report long after their acute infection has resolved. Emerging reports are being published concerning COVID-19 and its chronic effects, yet limited knowledge of disease mechanisms has challenged therapeutic efforts. To address these issues, we review broadly the literature spanning 2020-2022 concerning the proposed mechanisms underlying NC-PASC, outline the long-term neurological sequelae associated with COVID-19, and discuss potential clinical interventions.

Post-COVID-19 Condition

An estimated 10-15% of those infected with SARS-CoV-2 may have post-COVID-19 condition. Common lingering signs and symptoms include shortness of breath, fatigue, high heart rate, and memory and cognitive dysfunction even several months after infection, often impacting survivors' quality of life. The prevalence and duration of individual symptoms remain difficult to ascertain due to the lack of standardized research methods across various studies and limited patient follow-up in clinical studies. Nonetheless, data indicate post-COVID-19 condition may occur independent of acuity of initial infection, hospitalization status, age, or pre-existing comorbidities. Risk factors may include female sex and underlying respiratory or psychiatric disease. Supportive therapies to mitigate symptoms remain the mainstay of treatment. Reassuringly, most patients experience a reduction in symptoms by 1 year. The use of a universal case definition and shared research methods will allow for further clarity regarding the pervasiveness of this entity and its long-term health consequences.

A case of dysautonomia after COVID-19 infection in a patient with poorly controlled type I diabetes

COVID-19 has been linked to dysautonomia in the current literature, as has uncontrolled diabetes. Here, we present a case report of severe dysautonomia following a COVID-19 infection in a patient with pre-existing poorly controlled type-1 diabetes. This patient exhibited symptoms consistent with both postural orthostatic tachycardia syndrome (POTS), as well as orthostatic hypotension. His symptoms became so severe that he was unable to come to a standing position without experiencing syncope. Extensive workup was completed to identify an alternative cause of his dysautonomia with inconclusive results. Dysautonomia can have devastating consequences in regard to physical, social, and psychological health. Counseling individuals with poorly controlled diabetes about the importance of maintaining tight blood glucose control and avoiding COVID-19 infection should be primary interventions when treating patients with this DM1. Early detection and management of diabetes mellitus, COVID-19, and of possible resultant dysautonomia through medical interventions, as well as lifestyle changes, are extremely important measures to avoid development of dangerous and potentially life-threatening consequences.

Is the post-COVID-19 syndrome a severe impairment of acetylcholine-orchestrated neuromodulation that responds to nicotine administration?

Following a SARS-CoV-2 infection, many individuals suffer from post-COVID-19 syndrome. It makes them unable to proceed with common everyday activities due to weakness, memory lapses, pain, dyspnea and other unspecific physical complaints. Several investigators could demonstrate that the SARS-CoV-2 related spike glycoprotein (SGP) attaches not only to ACE-2 receptors but also shows DNA sections highly affine to nicotinic acetylcholine receptors (nAChRs). The nAChR is the principal structure of cholinergic neuromodulation and is responsible for coordinated neuronal network interaction. Non-intrinsic viral nAChR attachment compromises integrative interneuronal communication substantially. This explains the cognitive, neuromuscular and mood impairment, as well as the vegetative symptoms, characterizing post-COVID-19 syndrome. The agonist ligand nicotine shows an up to 30-fold higher affinity to nACHRs than acetylcholine (ACh). We therefore hypothesize that this molecule could displace the virus from nAChR attachment and pave the way for unimpaired cholinergic signal transmission. Treating several individuals suffering from post-COVID-19 syndrome with a nicotine patch application, we witnessed improvements ranging from immediate and substantial to complete remission in a matter of days.

Sociodemographic, economic, physical, and mental health status of previously hospitalised patients with COVID-19 symptoms in Bangladesh: Protocol for a mixed-method study

Introduction

Not much is known about the long-term consequences of COVID-19, popularly known as long COVID. This is particularly so in terms of patterns and clusters of symptoms over time, sociodemographic and economic characteristics of patients, and related clinical history. This is crucial for resource-constrained health systems such as Bangladesh to address long COVID as a forthcoming challenge. This protocol aims to investigate the consequences of COVID-19 over time for physical and mental health and how these are associated with demographic and socio-economic factors.

Methods and analysis

This mixed-method study collected information on all patients with symptoms of COVID-19 admitted to and discharged after recovery from a COVID-19-dedicated hospital in Bangladesh (N = 942), from April to December 2020. The sources of data were admission records and discharge certificates from the hospital for clinical history, cross-sectional survey on physical and mental health (assessed by DASS21 scale)-related symptoms and socioeconomic changes after recovery, and qualitative in-depth interviews on experiences of COVID-19. Interviews were conducted over the phone. Quantitative analysis was done to estimate the prevalence of physical and mental health consequences of COVID-19 after recovery and the association with socio-economic and demographic information. The qualitative analysis was performed using a thematic analysis approach.

Discussion

It is imperative to understand the post-COVID consequences and related health and non-health aspects to inform evidence-based policymaking, especially for resource-poor contexts such as Bangladesh. Given the dearth of evidence in this regard, the proposed study will contribute to bridging this knowledge gap. It is important to note that this study is one of the few which presents information on post-COVID-19 consequences in the context of low- and middle-income countries and the first in Bangladesh.

[Impact of COVID-19 on some neurological and psychological features in epilepsy]

The new coronavirus infection spread around the world in a very short time and turned into a pandemic with a wave-like flow for more than two years. COVID-19infection affects selectively various organs and systems, including the nervous system; neurological manifestations have been reported, including anosmia, encephalopathy, stroke, epileptogenic disorders, which necessitates studies of the course of brain diseases, among which epilepsy occupies a significant place.

Cholinergic deficiency in the cholinergic system as a pathogenetic link in the formation of various syndromes in COVID-19

According to recent data, several mechanisms of viral invasion of the central nervous system (CNS) have been proposed, one of which is both direct penetration of the virus through afferent nerve fibers and damage to the endothelium of cerebral vessels. It has been proven that the SARS-CoV-2 virus affects pathologically not only the human cardiorespiratory system but is also associated with a wide range of neurological diseases, cerebrovascular accidents, and neuromuscular pathologies. However, the observed post-COVID symptom complex in patients, manifested in the form of headache, "fog in the head," high temperature, muscle weakness, lowering blood pressure, does it make us think about the pathophysiological mechanisms that contribute to the development of this clinical picture? One possible explanation is a disruption in the signaling of the acetylcholine system (AChS) in the body. Viral invasions, and in particular COVID-19, can negatively affect the work of the AChS, disrupting its coordination activities. Therefore, the main goal of this literature review is to analyze the information and substantiate the possible mechanisms for the occurrence of post-COVID syndrome in people who have had COVID-19 from the standpoint of AChS dysfunctions.

Cardiovascular Implications of microRNAs in Coronavirus Disease 2019

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic continues to be a global challenge due to resulting morbidity and mortality. Cardiovascular (CV) involvement is a crucial complication in coronavirus disease 2019 (COVID-19), and no strategies are available to prevent or specifically address CV events in COVID-19 patients. The identification of molecular partners contributing to CV manifestations in COVID-19 patients is crucial for providing early biomarkers, prognostic predictors, and new therapeutic targets. The current report will focus on the role of microRNAs (miRNAs) in CV complications associated with COVID-19. Indeed, miRNAs have been proposed as valuable biomarkers and predictors of both cardiac and vascular damage occurring in SARS-CoV-2 infection. SIGNIFICANCE STATEMENT: It is essential to identify the molecular mediators of coronavirus disease 2019 (COVID-19) cardiovascular (CV) complications. This report focused on the role of microRNAs in CV complications associated with COVID-19, discussing their potential use as biomarkers, prognostic predictors, and therapeutic targets.

Within and between-day variation and associations of symptoms in Long Covid: Intensive longitudinal study

BACKGROUND

People with Long Covid (Post Covid-19 Condition) describe multiple symptoms which vary between and within individuals over relatively short time intervals. We aimed to describe the real-time associations between different symptoms and between symptoms and physical activity at the individual patient level.

METHODS AND FINDINGS

Intensive longitudinal study of 82 adults with self-reported Long Covid (median duration 12-18 months). Data collection involved a smartphone app with 5 daily entries over 14 days and continuous wearing of a wrist accelerometer. Data items included 7 symptoms (Visual Analog Scales) and perceived demands in the preceding period (Likert scales). Activity was measured using mean acceleration in the 3-hour periods preceding and following app data entry. Analysis used within-person correlations of symptoms pairs and both pooled and individual symptom networks derived from graphical vector autoregression. App data was suitable for analysis from 74 participants (90%) comprising 4022 entries representing 77.6% of possible entries. Symptoms varied substantially within individuals and were only weakly autocorrelated. The strongest between-subject symptom correlations were of fatigue with pain (partial coefficient 0.5) and cognitive difficulty with light-headedness (0.41). Pooled within-subject correlations showed fatigue correlated with cognitive difficulty (partial coefficient 0.2) pain (0.19) breathlessness (0.15) and light-headedness (0.12) but not anxiety. Cognitive difficulty was correlated with anxiety and light-headedness (partial coefficients 0.16 and 0.17). Individual participant correlation heatmaps and symptom networks showed no clear patterns indicative of distinct phenotypes. Symptoms, including fatigue, were inconsistently correlated with prior or subsequent physical activity: this may reflect adjustment of activity in response to symptoms. Delayed worsening of symptoms after the highest activity peak was observed in 7 participants.

CONCLUSION

Symptoms of Long Covid vary within individuals over short time scales, with heterogenous patterns of symptom correlation. The findings are compatible with altered central symptom processing as an additional factor in Long Covid.

Role of Wearable Sensing Technology to Manage Long COVID

Long COVID consequences have changed the perception towards disease management, and it is moving towards personal healthcare monitoring. In this regard, wearable devices have revolutionized the personal healthcare sector to track and monitor physiological parameters of the human body continuously. This would be largely beneficial for early detection (asymptomatic and pre-symptomatic cases of COVID-19), live patient conditions, and long COVID monitoring (COVID recovered patients and healthy individuals) for better COVID-19 management. There are multitude of wearable devices that can observe various human body parameters for remotely monitoring patients and self-monitoring mode for individuals. Smart watches, smart tattoos, rings, smart facemasks, nano-patches, etc., have emerged as the monitoring devices for key physiological parameters, such as body temperature, respiration rate, heart rate, oxygen level, etc. This review includes long COVID challenges for frequent monitoring of biometrics and its possible solution with wearable device technologies for diagnosis and post-therapy of diseases.

Cardiovascular Manifestations of Long COVID: A Review

The acute phase of severe acute respiratory syndrome coronavirus 2 [coronavirus disease (COVID)] infection has many well-documented cardiovascular manifestations, however, the long-term sequelae are less understood. In this focused review, we explore the risk factors, character, and rates of cardiovascular events in patients with Long COVID, which is defined as symptoms occurring more than 4 weeks following initial infection. Research has identified increased rates of cerebrovascular disease, dysrhythmias, ischemic and inflammatory heart disease, cardiopulmonary symptoms, and thrombotic events among those with Long COVID, though the risk rates and potential mechanisms behind each cardiovascular event vary. Finally, we discuss the current gaps in the literature as well as how COVID compares to other viral infections when it comes to causing long-term cardiovascular sequelae.

Neurological Signs of Postcovid Syndrome

The challenge of postcovid syndrome (PCS) is of great interest due to its wide distribution and variety of clinical signs. The main neurological signs of PCS are discussed. Data on the presumptive mechanisms forming PCS are presented. The potential for using the drug Mexidol to treat patients with PCS is addressed.