Autonomic dysfunction in post-COVID patients with and witfhout neurological symptoms: a prospective multidomain observational study

Neurological long-COVID: Associations among fatigue, dysautonomia, depression, and subjective memory complaints

INTRODUCTION

Long-COVID is a multisystem disease characterized by a varied presentation of symptoms. According to most recent research, the most common symptom of long-COVID is fatigue, which up to this date lacks a universally accepted definition. This study aimed to investigate neurocognitive and physical manifestations of neurological long-COVID, particularly fatigue and its relation with autonomic disfunction, cognitive impairment (known as, brain fog), and depressive symptoms. Furthermore, the study provided insights into predictors of fatigue in long-COVID.

METHODS

The included patients (n=141) were referred to the neuro-long-COVID ambulatory service of Trieste from 30 September 2021-02 March 2022. Patients were given self-reporting questionnaires to screen for fatigue, autonomic dysfunction, cognitive impairment and depressive symptoms. The questionnaires adopted for these conditions to be assessed were Fatigue Severity Scale (FSS), COMPASS-31, Prospective-Retrospective Memory Questionnaire (PRMQ), and Beck Depression Inventory (BDI). Participants were divided into two groups, fatigued and non-fatigued patients, based on FSS scoring (scores > 4.67 indicate fatigued patients). The questionnaire scores of the two groups were then compared.

RESULTS

Fatigued patients had significantly higher scores in COMPASS (p<0.001, Cohen's d=1.077), BDI (p<0.001, Cohen's d=0.862), and PRMQ ( p<0.001, Cohen's d=1.159). Furthermore, the multivariate regression analysis showed that predictors of fatigue in long-COVID were symptomatological burden in acute infection (OR=1.38, 95 % CI 1.020-1.887, p=0.037) and in long-COVID (OR=1.78, 95 % CI 1.133-2.2824, p=0.013), COMPASS-31>16 (OR=3.44, 95 % CI 1240-9.560, p=0.018) and BDI>15 (OR=5.1, 95 % CI 1.715-15.164, p=0.003).

CONCLUSION

This study showed associations between fatigue, dysautonomia and depression, as well as with symptom burden in acute and long-COVID.

How to understand the overlap of long COVID, chronic fatigue syndrome/myalgic encephalomyelitis, fibromyalgia and irritable bowel syndromes

Long COVID should be limited to patients with multiple, persistent symptoms not related to well-defined organ damage. Once redefined, a focused review of long COVID demonstrates striking similarity to chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), fibromyalgia (FM) and irritable bowel syndrome (IBS). Research in long COVID has revealed similar findings to those noted in CFS/ME and FM, characterized by central nervous system organ dysfunction. Long COVID, like CFS/ME, FM and IBS, is best understood as a bidirectional mind-body, neuroimmune illness.

Composite Autonomic Symptom Score-31 for the diagnosis of cardiovascular autonomic dysfunction in long-term coronavirus disease 2019

BACKGROUND

Composite Autonomic Symptom Score-31 (COMPASS-31) is an easy-to-use screening tool for the evaluation of autonomic dysfunction in various diseases affecting neural function but has rarely been used in the assessment of long coronavirus disease 2019 (COVID-19). This study aimed to evaluate the diagnostic accuracy of the COMPASS-31 score in detecting dysfunction of the autonomic nervous system in patients 3 months after COVID-19 infection.

MATERIALS AND METHODS

Fifty-nine subjects were recruited and grouped into 2: (a) controls (n = 31) who had never had positive polymerase chain reaction results for COVID-19 before and (b) the post-COVID-19 patients (n = 28) who had confirmed COVID-19 infection 3-6 months before recruitment. COMPASS-31 questionnaire was utilized to evaluate subjective symptoms or evidence of autonomic dysfunction. Autonomic dysfunction was assessed objectively by cardiovascular autonomic reflex tests (CARTs) and heart rate variability (HRV). For comparison of quantitative variables between two groups, t-test or Mann-Whitney U test, as appropriate, were used. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), negative likelihood ratio (LR), and positive LR were used as measures of diagnostic accuracy. Receiver operating characteristic (ROC) curve analysis determined the overall accuracy of COMPASS-31.

RESULTS

The median COMPASS score was found to be significantly higher in post-COVID-19 participants than controls (15.5 vs. 10, P = 0.021). The median total CART score was also significantly higher in post-COVID-19 participants (0 vs. 1, P < 0.001). Out of 6 domains of the COMPASS score, the median value for orthostatic dysfunction was found to be significantly higher in post-COVID-19 participants than controls (12 vs. 0, P = 0.008). There was significantly fair accuracy of the COMPASS score with an area under the receiver operating curve 0.68 (0.54-0.82) following the total CART score ≥2 as the gold standard in the diagnosis of autonomic dysfunction (P = 0.021). The best cutoff point of the total COMPASS score was 12.5, where the optimal values of sensitivity, specificity, and positive and negative predictive values were achieved. Nonsignificant and weak correlations between CARTs, HRV parameters, and COMPASS score were found.

CONCLUSION

COMPASS-31 could be used as a user-friendly screening tool to detect autonomic dysfunction in post-COVID-19 cases with acceptable sensitivity and specificity.

Exploration of COVID-19 associated bradycardia using heart rate variability analysis in a case-control study of ARDS patients

BACKGROUND

Bradycardia and dysautonomia observed during SARS-Cov2 infection suggests involvement of the autonomic nervous system (ANS). Limited data exists on ANS dysregulation and its association with outcomes in patients with acute respiratory distress syndrome (ARDS) related to COVID-19 (C-ARDS) or other etiologies (NC-ARDS).

OBJECTIVES

We aimed to explore sympathovagal balance, assessed by heart rate variability (HRV), and its clinical prognostic value in C-ARDS compared with NC-ARDS.

METHODS

A single-center, prospective case-control study was conducted. Consecutive patients meeting ARDS criteria between 2020 and 2022 were included. HRV was assessed using 1-hour electrographic tracing during a stable, daytime period.

RESULTS

Twenty-four patients with C-ARDS and 19 with NC-ARDS were included. Age, sex and ARDS severity were similar between groups. The median heart rate was markedly lower in the C-ARDS group than in the NC-ARDS group (60 [53-72] versus 101 [91-112] bpm, p<.001). Most of HRV parameters were significantly increased in patients with C-ARDS. HRV correlated with heart rate only in patients with C-ARDS. A positive correlation was found between the low-to high-frequency ratio (LF/HF) and length of intensive care unit stay (r = 0.576, p<.001).

CONCLUSION

This study confirmed that C-ARDS was associated with marked bradycardia and severe ANS impairment, suggesting a sympathovagal imbalance with vagal overtone. Poor outcomes appeared to be more related to sympathetic rather than parasympathetic hyperactivation.

Long-COVID autonomic syndrome in working age and work ability impairment

Long-COVID19 has been recently associated with long-sick leave and unemployment. The autonomic nervous system functioning may be also affected by SARS-CoV-2, leading to a chronic autonomic syndrome. This latter remains widely unrecognized in clinical practice. In the present study, we assessed the occurrence of Long-COVID19 Autonomic Syndrome in a group of active workers as well as the relationships between their autonomic dysfunction and work ability. This prospective observational study was conducted during the 2nd wave of the pandemic in Italy. Forty-five patients (53.6 ± 8.4 years; 32 M) hospitalized for COVID19, were consecutively enrolled at the time of their hospital discharge (T0) and followed-up for 6 months. Autonomic symptoms and work ability were assessed by COMPASS31 and Work Ability Index questionnaires at T0, one (T1), three and six (T6) months after hospital discharge and compared to those retrospectively collected for a period preceding SARS-CoV-2 infection. Clinical examination and standing test were also performed at T1 and T6. One in three working-age people developed a new autonomic syndrome that was still evident 6 months after the acute infection resolution. This was associated with a significant reduction in the work ability. Recognition of Long-COVID19 Autonomic Syndrome may promote early intervention to facilitate return to work and prevent unemployment.

Long COVID in Children, Adults, and Vulnerable Populations: A Comprehensive Overview for an Integrated Approach

Long COVID affects both children and adults, including subjects who experienced severe, mild, or even asymptomatic SARS-CoV-2 infection. We have provided a comprehensive overview of the incidence, clinical characteristics, risk factors, and outcomes of persistent COVID-19 symptoms in both children and adults, encompassing vulnerable populations, such as pregnant women and oncological patients. Our objective is to emphasize the critical significance of adopting an integrated approach for the early detection and appropriate management of long COVID. The incidence and severity of long COVID symptoms can have a significant impact on the quality of life of patients and the course of disease in the case of pre-existing pathologies. Particularly, in fragile and vulnerable patients, the presence of PASC is related to significantly worse survival, independent from pre-existing vulnerabilities and treatment. It is important try to achieve an early recognition and management. Various mechanisms are implicated, resulting in a wide range of clinical presentations. Understanding the specific mechanisms and risk factors involved in long COVID is crucial for tailoring effective interventions and support strategies. Management approaches involve comprehensive biopsychosocial assessments and treatment of symptoms and comorbidities, such as autonomic dysfunction, as well as multidisciplinary rehabilitation. The overall course of long COVID is one of gradual improvement, with recovery observed in the majority, though not all, of patients. As the research on long-COVID continues to evolve, ongoing studies are likely to shed more light on the intricate relationship between chronic diseases, such as oncological status, cardiovascular diseases, psychiatric disorders, and the persistent effects of SARS-CoV-2 infection. This information could guide healthcare providers, researchers, and policymakers in developing targeted interventions.

Efficacy of dual-task augmented reality rehabilitation in non-hospitalized adults with self-reported long COVID fatigue and cognitive impairment: a pilot study

BACKGROUND

Cognitive impairment and chronic fatigue represent common characteristics of the long COVID syndrome. Different non-pharmacological treatments have been proposed, and physiotherapy has been proposed to improve the symptoms. This study aimed to evaluate the effects of a dual-task augmented reality rehabilitation protocol in people with long COVID fatigue and cognitive impairment.

METHODS AND MATERIALS

Ten non-hospitalized adults with reported fatigue and "brain fog" symptoms after COVID (7/10 females, 50 years, range 41-58) who participated in 20 sessions of a 1-h "dual-task" training, were compared to 10 long COVID individuals with similar demographics and symptoms (9/10 females, 56 years, range 43-65), who did not participate to any rehabilitation protocol. Cognitive performance was assessed with the Trail Making Test (TMT-A and -B) and Frontal Assessment Battery (FAB), and cardiovascular and muscular fatigue were assessed with the fatigue severity scale (FSS), six-minute walking test and handgrip endurance. Finally, transcranial magnetic stimulation (TMS) investigated cortical excitability.

RESULTS

The mixed-factors analysis of variance found a significant interaction effect only in cognitive performance evaluation, suggesting TMT-B execution time decreased (- 15.9 s, 95% CI 7.6-24.1, P = 0.001) and FAB score improved (1.88, 95% CI 2.93-0.82, P = 0.002) only in the physiotherapy group. For the remaining outcomes, no interaction effect was found, and most parameters similarly improved in the two groups.

CONCLUSION

The preliminary results from this study suggest that dual-task rehabilitation could be a feasible protocol to support cognitive symptoms recovery after COVID-19 and could be helpful in those individuals suffering from persisting and invalidating symptoms.

Identification of predictive patient characteristics for assessing the probability of COVID-19 in-hospital mortality

As the world emerges from the COVID-19 pandemic, there is an urgent need to understand patient factors that may be used to predict the occurrence of severe cases and patient mortality. Approximately 20% of SARS-CoV-2 infections lead to acute respiratory distress syndrome caused by the harmful actions of inflammatory mediators. Patients with severe COVID-19 are often afflicted with neurologic symptoms, and individuals with pre-existing neurodegenerative disease have an increased risk of severe COVID-19. Although collectively, these observations point to a bidirectional relationship between severe COVID-19 and neurologic disorders, little is known about the underlying mechanisms. Here, we analyzed the electronic health records of 471 patients with severe COVID-19 to identify clinical characteristics most predictive of mortality. Feature discovery was conducted by training a regularized logistic regression classifier that serves as a machine-learning model with an embedded feature selection capability. SHAP analysis using the trained classifier revealed that a small ensemble of readily observable clinical features, including characteristics associated with cognitive impairment, could predict in-hospital mortality with an accuracy greater than 0.85 (expressed as the area under the ROC curve of the classifier). These findings have important implications for the prioritization of clinical measures used to identify patients with COVID-19 (and, potentially, other forms of acute respiratory distress syndrome) having an elevated risk of death.

Autoimmune Autonomic Neuropathy: From Pathogenesis to Diagnosis

Autoimmune autonomic ganglionopathy (AAG) is a disease of autonomic failure caused by ganglionic acetylcholine receptor (gAChR) autoantibodies. Although the detection of autoantibodies is important for distinguishing the disease from other neuropathies that present with autonomic dysfunction, other factors are important for accurate diagnosis. Here, we provide a comprehensive review of the clinical features of AAG, highlighting differences in clinical course, clinical presentation, and laboratory findings from other neuropathies presenting with autonomic symptoms. The first step in diagnosing AAG is careful history taking, which should reveal whether the mode of onset is acute or chronic, followed by an examination of the time course of disease progression, including the presentation of autonomic and extra-autonomic symptoms. AAG is a neuropathy that should be differentiated from other neuropathies when the patient presents with autonomic dysfunction. Immune-mediated neuropathies, such as acute autonomic sensory neuropathy, are sometimes difficult to differentiate, and therefore, differences in clinical and laboratory findings should be well understood. Other non-neuropathic conditions, such as postural orthostatic tachycardia syndrome, chronic fatigue syndrome, and long COVID, also present with symptoms similar to those of AAG. Although often challenging, efforts should be made to differentiate among the disease candidates.

Different but the Same: Common Themes in Illness Experience Among People With Diverse Long COVID Symptoms and the Potential Benefits of Virtual Group Medical Visits

Long coronavirus disease 2019 (COVID-19) is poorly understood, widespread and debilitating. Integrative medical group visits (IMGVs) provide group medical care virtually or in person and are reimbursed by insurance payors. IMGV introduces integrative modalities such as mindfulness, nutrition, and acupressure in a person-centered, supportive, and educational environment. To evaluate a telehealth IMGV program called Nourish to Flourish (N2F) for patients with long COVID, three researchers conducted a qualitative analysis of pre- and post-group individual interviews. Twenty-five patients provided interviews, of which fifteen included pre- and post-group individual interviews. Main themes were unpredictable symptom patterns, a common range of emotions associated with long COVID experience, reconceptualizing self-identity, multiple barriers to care in conventional settings, and connections formed in N2F. Although symptoms varied, N2F participants found commonalities in their experiences of living with long COVID. They empathized with one another regarding changing symptoms, inconsistent social support, shifting identities, and barriers to effective medical care.

Cardiovascular effects of the post-COVID-19 condition

Throughout the COVID-19 pandemic, the new clinical entity of the post-COVID-19 condition, defined as a multisystemic condition of persistent symptoms following resolution of an acute severe acute respiratory syndrome coronavirus 2 infection, has emerged as an important area of clinical focus. While this syndrome spans multiple organ systems, cardiovascular complications are often the most prominent features. These include, but are not limited to, myocardial injury, heart failure, arrhythmias, vascular injury/thrombosis and dysautonomia. As the number of individuals with the post-COVID-19 condition continues to climb and overwhelm medical systems, summarizing existing information and knowledge gaps in the complex cardiovascular effects of the post-COVID-19 condition has become critical for patient care. In this Review, we explore the current state of knowledge of the post-COVID-19 condition and identify areas where additional research is warranted. This will provide a framework for better understanding the cardiovascular manifestations of the post-COVID-19 condition with a focus on pathophysiology, diagnosis and management.

Post-COVID dysautonomias: what we know and (mainly) what we don't know

Following on from the COVID-19 pandemic is another worldwide public health challenge that is referred to variously as long COVID, post-COVID syndrome or post-acute sequelae of SARS-CoV-2 infection (PASC). PASC comes in many forms and affects all body organs. This heterogeneous presentation suggests involvement of the autonomic nervous system (ANS), which has numerous roles in the maintenance of homeostasis and coordination of responses to various stressors. Thus far, studies of ANS dysregulation in people with PASC have been largely observational and descriptive, based on symptom inventories or objective but indirect measures of cardiovascular function, and have paid little attention to the adrenomedullary, hormonal and enteric nervous components of the ANS. Such investigations do not consider the syndromic nature of autonomic dysfunction. This Review provides an update on the literature relating to ANS abnormalities in people with post-COVID syndrome and presents a theoretical perspective on how the ANS might participate in common features of PASC.

Analysis of characteristics of and risk factors for otological symptoms after COVID-19 infection

The purpose of this study was to explore the characteristics of and risk factors for otological symptoms after contracting COVID-19. We invited 468 participants who had been infected with COVID-19 to participate in a survey. 310 (66.2%) were women and 158 (33.8%) were men. The mean age is 38.73 (12.21) years. The questionnaire included their basic information, symptoms and symptom duration after SARS-CoV-2 infection, number of vaccine doses received, and details regarding otological symptoms. In total, 106/468 (22.6%) participants experienced tinnitus, 66/468 (14.1%) hearing loss, 103/468 (22.0%) aural fullness, and 71/468 (15.2%) dizziness. Women were more prone to experience tinnitus (P = 0.022) and dizziness (P = 0.001) than men. The group with hearing loss were older (P = 0.025), and their initial COVID-19 symptoms lasted longer (P = 0.028) than those of patients without. Patients with aural fullness were more likely to experience fatigue than patients without (P = 0.002). Patients experiencing dizziness were more likely to experience pharyngalgia (P = 0.040) and fatigue (P = 0.005) than those without. The number of vaccine doses was positively associated with the resolution of otological symptoms (P = 0.035). Multiple logistic regression analysis revealed that sex was an independent risk factor for tinnitus (odds ratio [OR], 1.802; 95% confidence interval [CI], 1.099-2.953; P = 0.020), the duration of initial COVID-19 symptoms for hearing loss (OR, 1.055; 95% CI, 1.008-1.105; P = 0.023), and sex for dizziness (OR, 2.870; 95% CI, 1.489-5.535; P = 0.002). Sex, age, COVID-19-related fatigue, and the duration of initial COVID-19 symptoms may affect the occurrence of otological symptoms, and vaccines may aid their resolution.

The Impact of Long COVID-19 on the Cardiovascular System

Long coronavirus disease (COVID) is the development or persistence of symptoms after an acute SARS-CoV-2 (COVID-19) infection. Fewer patients are developing acute COVID-19 infections, but patients with long COVID continue to have alarming long-term sequelae. Many cardiac magnetic resonance imaging studies show significant changes in cardiac structure after a COVID-19 infection, suggestive of an increased burden of many cardiovascular diseases, notably myocarditis. The pathophysiology of COVID-19 requires viral binding to angiotensin-converting enzyme 2 protein receptors throughout the body, which are upregulated by inflammation. Consequently, the numerous preexisting conditions that worsen or prolong inflammation enhance this binding and have differing effects on patients based on their unique immune systems. These pathophysiological changes drive long COVID cardiac sequelae such as inappropriate sinus tachycardia, postural orthostatic tachycardia, and other types of orthostatic intolerance. Increased screening for long COVID and low-risk interventions such as exercise regimens could alleviate the suffering endured by patients with long COVID. Many studies such as the Researching COVID to Enhance Recovery Initiative (RECOVER) trials at the National Institutes of Health are exploring potential treatments for long COVID patients.

Autonomic Manifestations of Long-COVID Syndrome

PURPOSE OF REVIEW

Long-COVID is a novel condition emerging from the COVID-19 pandemic. Long-COVID is characterized by symptoms commonly seen in autonomic disorders including fatigue, brain fog, light-headedness, and palpitations. This article will critically evaluate recent findings and studies on Long-COVID and its physiological autonomic manifestations.

RECENT FINDINGS

Studies have reported on the prevalence of different symptoms and autonomic disorders in Long-COVID cohorts. Autonomic nervous system function, including both the parasympathetic and sympathetic limbs, has been studied using different testing techniques in Long-COVID patients. While numerous mechanisms may contribute to Long-COVID autonomic pathophysiology, it is currently unclear which ones lead to a Long-COVID presentation. To date, studies have not tested treatment options for autonomic disorders in Long-COVID patients. Long-COVID is associated with autonomic abnormalities. There is a high prevalence of clinical autonomic disorders among Long-COVID patients, with limited knowledge of the underlying mechanisms and the effectiveness of treatment options.

Recognizing postural orthostatic tachycardia syndrome in primary care

ABSTRACT

Postural orthostatic tachycardia syndrome (POTS) is a complex autonomic disorder characterized by abnormal tachycardia on standing. This disorder predominantly affects young women, with a peak incidence between ages 20 and 30 years. POTS often is associated with a variety of symptoms, including dizziness, palpitations, fatigue, generalized weakness, anxiety, and exercise intolerance, which can significantly impair patient quality of life. Primary care providers (PCPs) often are the first healthcare professionals to whom patients present. This article provides an overview of POTS, including diagnostic criteria and the importance of a thorough clinical evaluation to rule out other causes of symptoms. PCPs play a critical role in the comprehensive approach to care, involving patient education, lifestyle modifications, and treatment to improve outcomes and enhance patient quality of life.

Analysis of the correlation between heart rate variability and palpitation symptoms in female patients with long COVID

Objectives

To analyze the correlation between heart rate variability (HRV) and palpitation symptoms in female patients with long COVID.

Methods

A total of 272 female healthcare workers who were infected with SARS-CoV-2 for the first time in December 2022 at Fuzhou First Hospital affiliated with Fujian Medical University, were selected as study subjects. These subjects were divided into three groups based on their symptoms: a group with palpitations (70 cases), a group without palpitations but with other symptoms (124 cases), and a group consisting of asymptomatic cases (78 cases). The study compared the general information, COMPASS-31 scores, quality of life scores, and HRV parameters among the three groups. Furthermore, it analyzed the factors influencing palpitation symptoms in female patients with long COVID.

Results

Compared to the other two groups, the HRV parameters SDNN, HRVIndex, LF, and TP were significantly reduced in the group with palpitations (p < 0.05). Multivariate analysis revealed that HRVIndex (p = 0.016; OR: 0.966, 95% CI: 0.940∼0.994) had a significant impact on palpitation symptoms in female patients with long COVID.

Conclusions

The symptoms of palpitations in female patients with long COVID were found to be related to HRV parameters. Autonomic dysfunction may be connected to the occurrence of palpitation symptoms in long COVID.

Evaluation and treatment approaches for neurological post-acute sequelae of COVID-19: A consensus statement and scoping review from the global COVID-19 neuro research coalition

Post-acute neurological sequelae of COVID-19 affect millions of people worldwide, yet little data is available to guide treatment strategies for the most common symptoms. We conducted a scoping review of PubMed/Medline from 1/1/2020-4/1/2023 to identify studies addressing diagnosis and treatment of the most common post-acute neurological sequelae of COVID-19 including: cognitive impairment, sleep disorders, headache, dizziness/lightheadedness, fatigue, weakness, numbness/pain, anxiety, depression and post-traumatic stress disorder. Utilizing the available literature and international disease-specific society guidelines, we constructed symptom-based differential diagnoses, evaluation and management paradigms. This pragmatic, evidence-based consensus document may serve as a guide for a holistic approach to post-COVID neurological care and will complement future clinical trials by outlining best practices in the evaluation and treatment of post-acute neurological signs/symptoms.

Dysautonomia, but Not Cardiac Dysfunction, Is Common in a Cohort of Individuals with Long COVID

Despite the prevalence of dysautonomia in people with Long COVID, it is currently unknown whether Long COVID dysautonomia is routinely accompanied by structural or functional cardiac alterations. In this retrospective observational study, the presence of echocardiographic abnormalities was assessed. Left ventricular (LV) chamber sizes were correlated to diagnostic categories and symptoms via standardized patient-reported outcome (PRO) questionnaires. A total of 203 individuals with Long COVID without pre-existing cardiac disease and with available echocardiograms were included (mean age, 45 years; 67% female). Overall, symptoms and PRO scores for fatigue, breathlessness, quality of life, disability, anxiety and depression were not different between those classified with post-COVID dysautonomia (PCD, 22%) and those unclassified (78%). An LV internal diameter at an end-diastole z score < -2 was observed in 33 (16.5%) individuals, and stroke volume (SV) was lower in the PCD vs. unclassified subgroup (51.6 vs. 59.2 mL, 95% C.I. 47.1-56.1 vs. 56.2-62.3). LV end-diastolic volume (mean diff. (95% CI) -13 [-1--26] mL, p = 0.04) and SV (-10 [-1--20] mL, p = 0.03) were smaller in those individuals reporting a reduction in physical activity post-COVID-19 infection, and smaller LVMI was weakly correlated with worse fatigue (r = 0.23, p = 0.02). The majority of individuals with Long COVID report shared symptoms and did not demonstrate cardiac dysfunction on echocardiography.

Association between COVID-19 and sexual health: an umbrella review

PURPOSE

We conducted this umbrella review to review the current evidence on the relationship between COVID-19 and sexual health in both men and women.

METHODS

We conducted searches in Pubmed, Embase, and the Cochrane dataset for meta-analyses that met our pre-set inclusion criteria. We included studies with detailed information investigating the link between COVID-19 and sexual health in men/women. We did not limit the language.

RESULTS

The results of the included studies frequently relied on the Female Sexual Function Index to assess sexual health in women. For men, the International Index of Male Function and hospital diagnoses were commonly used to assess sexual health. Currently, there is conflicting evidence regarding the impact of COVID-19 on sexual health. However, since most studies were observational in nature, additional study designs are necessary to draw definitive conclusions across different contexts.

CONCLUSION

Our findings highlight the importance of sexual health among COVID-19 patients and people affected due to COVID-19. Further critical studies should investigate the mechanism underlying the association between COVID-19 and sexual health.

Long COVID: Clinical Findings, Pathology, and Endothelial Molecular Mechanisms

Persistence of COVID-19 symptoms may follow severe acute respiratory syndrome coronavirus 2 infection. The incidence of long COVID increases with the severity of acute disease, but even mild disease can be associated with sequelae. The symptoms vary widely, with fatigue, shortness of breath, and cognitive dysfunction the most common. Abnormalities of multiple organs have been documented, and histopathology has revealed widespread microthrombi. Elevated levels of complement are present in acute COVID-19 patients and may persist at lower levels in long COVID. Evidence supports complement activation, with endotheliopathy-associated disease as the molecular mechanism causing both acute and long COVID.

Prevalence, pathogenesis and spectrum of neurological symptoms in COVID-19 and post-COVID-19 syndrome: a narrative review

Neurological symptoms are not uncommon during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and reflect a broad spectrum of neurological disorders of which clinicians should be aware. The underlying pathogenesis of neurological disease in coronavirus disease 2019 (COVID-19) may be due to four mechanisms of nervous system dysfunction and injury: i) direct viral neurological invasion; ii) immune dysregulation; iii) endothelial dysfunction and coagulopathy; and iv) severe systemic COVID-19 disease. Neurological manifestations of acute COVID-19 include headache, peripheral neuropathies, seizures, encephalitis, Guillain-Barré syndrome, and cerebrovascular disease. Commonly reported long term neurological sequelae of COVID-19 are cognitive dysfunction and dysautonomia, which despite being associated with severe acute disease are also seen in people with mild disease. Assessment of cognitive dysfunction after COVID-19 is confounded by a high prevalence of comorbid fatigue, anxiety, and mood disorders. However, other markers of neuroaxonal breakdown suggest no significant neuronal injury apart from during severe acute COVID-19. The long term impact of COVID-19 on neurological diseases remains uncertain and requires ongoing vigilance.

Cardiovascular autonomic dysfunction in "Long COVID": pathophysiology, heart rate variability, and inflammatory markers

Long COVID is characterized by persistent signs and symptoms that continue or develop for more than 4 weeks after acute COVID-19 infection. Patients with Long COVID experience a cardiovascular autonomic imbalance known as dysautonomia. However, the underlying autonomic pathophysiological mechanisms behind this remain unclear. Current hypotheses include neurotropism, cytokine storms, and inflammatory persistence. Certain immunological factors indicate autoimmune dysfunction, which can be used to identify patients at a higher risk of Long COVID. Heart rate variability can indicate autonomic imbalances in individuals suffering from Long COVID, and measurement is a non-invasive and low-cost method for assessing cardiovascular autonomic modulation. Additionally, biochemical inflammatory markers are used for diagnosing and monitoring Long COVID. These inflammatory markers can be used to improve the understanding of the mechanisms driving the inflammatory response and its effects on the sympathetic and parasympathetic pathways of the autonomic nervous system. Autonomic imbalances in patients with Long COVID may result in lower heart rate variability, impaired vagal activity, and substantial sympathovagal imbalance. New research on this subject must be encouraged to enhance the understanding of the long-term risks that cardiovascular autonomic imbalances can cause in individuals with Long COVID.

Postural orthostatic tachycardia syndrome and other related dysautonomic disorders after SARS-CoV-2 infection and after COVID-19 messenger RNA vaccination

The COVID-19 pandemic has caused a challenge for our society due to the post-acute sequelae of the disease. Persistent symptoms and long-term multiorgan complications, known as post-acute COVID-19 syndrome, can occur beyond 4 weeks from the onset of the COVID-19 infection. Postural orthostatic tachycardia syndrome (POTS) is considered a variety of dysautonomia, which is characterized by chronic symptoms that occur with standing and a sustained increase in heart rate, without orthostatic hypotension. POTS can lead to debilitating symptoms, significant disability, and impaired quality of life. In this narrative review, the etiopathogenic basis, epidemiology, clinical manifestations, diagnosis, treatment, prognosis, and socioeconomic impact of POTS, as well as other related dysautonomic disorders, after COVID-19 infection and SARS-CoV-2 postvaccination, were discussed. After a search conducted in March 2023, a total of 89 relevant articles were selected from the PubMed, Google Scholar, and Web of Science databases. The review highlights the importance of recognizing and managing POTS after COVID-19 infection and vaccination, and the approach to autonomic disorders should be known by all specialists in different medical areas. The diagnosis of POTS requires a comprehensive clinical assessment, including a detailed medical history, physical examination, orthostatic vital signs, and autonomic function tests. The treatment of POTS after COVID-19 infection or vaccination is mainly focused on lifestyle modifications, such as increased fluid and salt intake, exercise, and graduated compression stockings. Pharmacotherapy, such as beta-blockers, fludrocortisone, midodrine, and ivabradine, may also be used in selected cases. Further research is needed to understand the underlying mechanisms, risk factors, and optimal treatment strategies for this complication.

Exercise Training in Non-Hospitalized Patients with Post-COVID-19 Syndrome-A Narrative Review

Post COVID-19 Syndrome (PCS) is the persistence of symptoms after an infection with SARS-CoV-2 in both hospitalized and non-hospitalized COVID-19 survivors. Exercise was proposed as a rehabilitation measure for PCS and early studies focused on patients post-hospital discharge. The objective of this review is to summarize the results of trials investigating exercise interventions in non-hospitalized subjects with PCS and propose practical recommendations concerning safe exercise programming. A literature search in the databases MEDLINE and Scopus was conducted until 26 July 2023 and resulted in seven studies that met the criteria. In total, 935 subjects with PCS were investigated. Exercise enhanced aerobic fitness and physical function and relieved symptoms of dyspnea, fatigue and depression. Participants reported lower Post COVID-19 Functional Status scores post-intervention. The exercise programs were well tolerated with no adverse events. To ensure safety, medical examinations should take place in advance and there should be a regular evaluation of the individual responses to the training. Caution is advised when working with patients suffering from post-exertional malaise or diagnosed with myalgic encephalomyelitis/chronic fatigue syndrome. There is a growing need for additional randomized controlled trials to investigate the effectiveness and safety of exercise in individuals with PCS.

[Myalgic encephalomyelitis/chronic fatigue syndrome: an overview of current evidence]

Over the past 5 years both media and scientific interest has surged regarding the disorder myalgic encephalomyelitis and chronic fatigue syndrome (ME/CFS), not least because of the clinically similar manifestation in long COVID or post-COVID. In this review we discuss the process of clinical diagnosis and randomized controlled therapeutic studies on ME/CFS, and the similarities or differences to long COVID and post-COVID. So far, neither clear pathophysiologically causal nor therapeutic evidence-based results on ME/CFS have been identified in the many years of scientific research. Given the evident psychiatric comorbidity rates in patients with a diagnosis of ME/CFS, a psychosomatic etiology of this syndrome should be considered. Furthermore, a precise and reliable diagnostic classification based on stricter criteria would benefit both pathophysiological and therapeutic research.

Autonomic modulation, spontaneous baroreflex sensitivity and fatigue in young men after COVID-19

Impaired autonomic modulation and baroreflex sensitivity (BRS) have been reported during and after COVID-19. Both impairments are associated with negative cardiovascular outcomes. If these impairments were to exist undetected in young men after COVID-19, they could lead to negative cardiovascular outcomes. Fatigue is associated with autonomic dysfunction during and after COVID-19. It is unclear if fatigue can be used as an indicator of impaired autonomic modulation and BRS after COVID-19. This study aims to compare parasympathetic modulation, sympathetic modulation, and BRS between young men who had COVID-19 versus controls and to determine if fatigue is associated with impaired autonomic modulation and BRS. Parasympathetic modulation as the high-frequency power of R-R intervals (lnHFR-R), sympathetic modulation as the low-frequency power of systolic blood pressure variability (LFSBP), and BRS as the -index were measured by power spectral density analysis. These variables were compared between 20 young men who had COVID-19 and 24 controls. Independent t-tests and Mann-Whitney U tests indicated no significant difference between the COVID-19 and the control group in: lnHFR-R, P=0.20; LFSBP, P=0.11, and -index, P=0.20. Fatigue was not associated with impaired autonomic modulation or BRS. There is no difference in autonomic modulations or BRS between young men who had COVID-19 compared to controls. Fatigue did not seem to be associated with impaired autonomic modulation or impaired BRS in young men after COVID-19. Findings suggest that young men might not be at increased cardiovascular risk from COVID-19-related dysautonomia and impaired BRS.

Impact of COVID-19 on employment: sociodemographic, medical, psychiatric and neuropsychological correlates

Introduction

Given the nature of the persistent physical and neuropsychiatric symptoms reported in the literature, among individuals after acute COVID illness; there is growing concern about the functional implications of the Post-Acute Sequelae of COVID-19 (PASC). We aim to evaluate associations of sociodemographic, medical, psychiatric and neuropsychological factors with employment status post COVID-19.

Methods

59 participants were administered a neuropsychiatric assessment and queried about employment status and occupational difficulties months after quarantine. Two levels of comparison were conducted: (1) Those who took time off work (TTO) to those with no time off (NTO); (2) Those who reported occupational performance suffered (PS) to those who did not (PDNS).

Results

TTO vs. NTO exhibited extensive differences across medical, psychiatric and neurocognitive domains. PS vs. PDNS differed on subjective measures of physical and cognitive symptoms, but not on objective testing.

Conclusion

Individuals who took time off beyond COVID-19 quarantine experience persistent physical, psychiatric, subjective and objective neurocognitive burden. In contrast, occupational impairment appears to reflect subjective complaints, but not objective measures. Clinical implications are discussed.

Deficient GABABergic and glutamatergic excitability in the motor cortex of patients with long-COVID and cognitive impairment

OBJECTIVE

Attention, working memory and executive processing have been reported to be consistently impaired in Neuro-Long coronavirus disease (COVID). On the hypothesis of abnormal cortical excitability, we investigated the functional state of inhibitory and excitatory cortical regulatory circuits by single "paired-pulse" transcranial magnetic stimulation (ppTMS) and Short-latency Afferent Inhibition (SAI).

METHODS

We compared clinical and neurophysiological data of 18 Long COVID patients complaining of persistent cognitive impairment with 16 Healthy control (HC) subjects. Cognitive status was evaluated by means of the Montreal Cognitive Assessment (MoCA) and a neuropsychological evaluation of the executive function domain; fatigue was scored by the Fatigue Severity Scale (FSS). Resting motor threshold (RMT), the amplitude of the motor evoked potential (MEP), Short Intra-cortical Inhibition (SICI), Intra-cortical Facilitation (ICF), Long-interval Intracortical Inhibition (LICI) and Short-afferent inhibition (SAI) were investigated over the motor (M1) cortex.

RESULTS

MoCA corrected scores were significantly different between the two groups (p = 0.023). The majority of the patients' performed sub-optimally in the neuropsychological assessment of the executive functions. The majority (77.80%) of the patients reported high levels of perceived fatigue in the FSS. RMT, MEPs, SICI and SAI were not significantly different between the two groups. On the other hand, Long COVID patients showed a reduced amount of inhibition in LICI (p = 0.003) and a significant reduction in ICF (p < 0.001).

CONCLUSIONS

Neuro-Long COVID patients performing sub-optimally in the executive functions showed a reduction of LICI related to GABAb inhibition and a reduction of ICF related to glutamatergic regulation. No alteration in cholinergic circuits was found.

SIGNIFICANCE

These findings can help to better understand the neurophysiological characteristics of Neuro-Long COVID, and in particular, motor cortex regulation in people with "brain fog".

High incidence of autonomic dysfunction and postural orthostatic tachycardia syndrome in patients with long-COVID: Implications for management and healthcare planning

BACKGROUND

Autonomic dysfunction including postural orthostatic tachycardia syndrome (POTS) has been reported in individuals with post-acute sequelae of Covid-19 (PASC). However, the degree of dysautonomia in PASC has not been compared to those with POTS and healthy controls.

METHODS

All participants were prospectively enrolled between 5^th August 2021 and 31^st October 2022. Autonomic testing included beat-to-beat hemodynamic monitoring to assess respiratory sinus arrhythmia, Valsalva ratio and orthostatic changes during a 10-minute active standing test as well as Sudomotor assessment. The Composite Autonomic Symptom Score (COMPASS-31) was used to assess symptoms and the Euroquol 5-Dimension survey (EQ-5D-5L) was used to assess health-related quality of life (HrQoL) measures.

RESULTS

A total of 99 participants (n=33 PASC, n=33 POTS and n=33 healthy controls; median age 32 [18], 85.9% females) were included. Compared to healthy controls, the PASC and POTS cohorts demonstrated significantly reduced respiratory sinus arrhythmia (p<0.001), greater heart rate increase during 10-minute active standing test (p<0.001), greater burden of autonomic dysfunction evidenced by higher COMPASS-31 scores across all subdomains (all p<0.001) and poor HrQoL across all EQ-5D-5L domains (all p<0.001), lower median EQ-VAS (p<0.001) and lower utility scores (p<0.001). The majority (79%) of those with PASC met the internationally established criteria for POTS.

CONCLUSION

The prevalence of autonomic symptomology or POTS was high in those with PASC, leading to poor HrQoL and high health disutility. Autonomic testing should be routinely undertaken in those with PASC to aid diagnosis and direct appropriate management to improve health outcomes.

TRIAL REGISTRATION

ANZCTR 12621000476831.

ME/CFS and Long COVID share similar symptoms and biological abnormalities: road map to the literature

Some patients remain unwell for months after "recovering" from acute COVID-19. They develop persistent fatigue, cognitive problems, headaches, disrupted sleep, myalgias and arthralgias, post-exertional malaise, orthostatic intolerance and other symptoms that greatly interfere with their ability to function and that can leave some people housebound and disabled. The illness (Long COVID) is similar to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) as well as to persisting illnesses that can follow a wide variety of other infectious agents and following major traumatic injury. Together, these illnesses are projected to cost the U.S. trillions of dollars. In this review, we first compare the symptoms of ME/CFS and Long COVID, noting the considerable similarities and the few differences. We then compare in extensive detail the underlying pathophysiology of these two conditions, focusing on abnormalities of the central and autonomic nervous system, lungs, heart, vasculature, immune system, gut microbiome, energy metabolism and redox balance. This comparison highlights how strong the evidence is for each abnormality, in each illness, and helps to set priorities for future investigation. The review provides a current road map to the extensive literature on the underlying biology of both illnesses.

Role of the one-minute sit-to-stand test in the diagnosis of post COVID-19 condition: a prospective cohort study

OBJECTIVE

To analyze the relationship between one-minute sit-to-stand test (1MSTST) parameters and a diagnosis of post COVID-19 condition in a cohort of patients who previously had COVID-19.

METHODS

This was a prospective cohort study of patients with post COVID-19 condition referred for body plethysmography at a tertiary university hospital. Post COVID-19 condition was defined in accordance with the current WHO criteria.

RESULTS

Fifty-three patients were analyzed. Of those, 25 (47.2%) met the clinical criteria for post COVID-19 condition. HR was lower in the patients with post COVID-19 condition than in those without it at 30 s after initiation of the 1MSTST (86.2 ± 14.3 bpm vs. 101.2 ± 14.7 bpm; p < 0.001) and at the end of the test (94.4 ± 18.2 bpm vs. 117.3 ± 15.3 bpm; p < 0.001). The ratio between HR at the end of the 1MSTST and age-predicted maximal HR (HRend/HRmax) was lower in the group of patients with post COVID-19 condition (p < 0.001). An HRend/HRmax of < 62.65% showed a sensitivity of 78.6% and a specificity of 82.0% for post COVID-19 condition. Mean SpO2 at the end of the 1MSTST was lower in the patients with post COVID-19 condition than in those without it (94.9 ± 3.6% vs. 96.8 ± 2.4%; p = 0.030). The former group of patients did fewer repetitions on the 1MSTST than did the latter (p = 0.020).

CONCLUSIONS

Lower SpO2 and HR at the end of the 1MSTST, as well as lower HR at 30 s after initiation of the test, were associated with post COVID-19 condition. In the appropriate clinical setting, an HRend/HRmax of < 62.65% should raise awareness for the possibility of post COVID-19 condition.

Parasympathetic autonomic dysfunction is more often evidenced than sympathetic autonomic dysfunction in fluctuating and polymorphic symptoms of "long-COVID" patients

Several disabling symptoms potentially related to dysautonomia have been reported in "long-COVID" patients. Unfortunately, these symptoms are often nonspecific, and autonomic nervous system explorations are rarely performed in these patients. This study aimed to evaluate prospectively a cohort of long-COVID patients presenting severe disabling and non-relapsing symptoms of potential dysautonomia and to identify sensitive tests. Autonomic function was assessed by clinical examination, the Schirmer test; sudomotor evaluation, orthostatic blood pressure (BP) variation, 24-h ambulatory BP monitoring for sympathetic evaluation, and heart rate variation during orthostatism, deep breathing and Valsalva maneuvers for parasympathetic evaluation. Test results were considered abnormal if they reached the lower thresholds defined in publications and in our department. We also compared mean values for autonomic function tests between patients and age-matched controls. Sixteen patients (median age 37 years [31-43 years], 15 women) were included in this study and referred 14.5 months (median) [12.0-16.5 months] after initial infection. Nine had at least one positive SARS-CoV-2 RT-PCR or serology result. Symptoms after SARS-CoV-2 infection were severe, fluctuating and disabling with effort intolerance. Six patients (37.5%) had one or several abnormal test results, affecting the parasympathetic cardiac function in five of them (31%). Mean Valsalva score was significantly lower in patients than in controls. In this cohort of severely disabled long-COVID patients, 37.5% of them had at least one abnormal test result showing a possible contribution of dysautonomia to these nonspecific symptoms. Interestingly, mean values of the Valsalva test were significantly lower in patients than in control subjects, suggesting that normal values thresholds might not be appropriate in this population.

Imbalance of Peripheral Temperature, Sympathovagal, and Cytokine Profile in Long COVID

A persistent state of inflammation has been reported during the COVID-19 pandemic. This study aimed to assess short-term heart rate variability (HRV), peripheral body temperature, and serum cytokine levels in patients with long COVID. We evaluated 202 patients with long COVID symptoms categorized them according to the duration of their COVID symptoms (≤120 days, n = 81; >120 days, n = 121), in addition to 95 healthy individuals selected as controls. All HRV variables differed significantly between the control group and patients with long COVID in the ≤120 days group (p < 0.05), and participants in the long COVID ≤120 days group had higher temperatures than those in the long COVID >120 days group in all regions analysed (p < 0.05). Cytokine analysis showed higher levels of interleukin 17 (IL-17) and interleukin 2 (IL-2), and lower levels of interleukin 4 (IL-4) (p < 0.05). Our results suggest a reduction in parasympathetic activation during long COVID and an increase in body temperature due to possible endothelial damage caused by the maintenance of elevated levels of inflammatory mediators. Furthermore, high serum levels of IL-17 and IL-2 and low levels of IL-4 appear to constitute a long-term profile of COVID-19 cytokines, and these markers are potential targets for long COVID-treatment and prevention strategies.

Detecting Orthostatic Intolerance in Long COVID in a Clinic Setting

INTRODUCTION

A likely mechanism of Long COVID (LC) is dysautonomia, manifesting as orthostatic intolerance (OI). In our LC service, all patients underwent a National Aeronautics and Space Administration (NASA) Lean Test (NLT), which can detect OI syndromes of Postural Tachycardia Syndrome (PoTS) or Orthostatic Hypotension (OH) in a clinic setting. Patients also completed the COVID-19 Yorkshire Rehabilitation Scale (C19-YRS), a validated LC outcome measure. Our objectives in this retrospective study were (1) to report on the findings of the NLT; and (2) to compare findings from the NLT with LC symptoms reported on the C19-YRS.

METHODS

NLT data, including maximum heart rate increase, blood pressure decrease, number of minutes completed and symptoms experienced during the NLT were extracted retrospectively, together with palpitation and dizziness scores from the C19-YRS. Mann-Witney U tests were used to examine for statistical difference in palpitation or dizziness scores between patients with normal NLT and those with abnormal NLT. Spearman's rank was used to examine the correlation between the degree of postural HR and BP change with C19-YRS symptom severity score.

RESULTS

Of the 100 patients with LC recruited, 38 experienced symptoms of OI during the NLT; 13 met the haemodynamic screening criteria for PoTS and 9 for OH. On the C19-YRS, 81 reported dizziness as at least a mild problem, and 68 for palpitations being at least a mild problem. There was no significant statistical difference between reported dizziness or palpitation scores in those with normal NLT and those with abnormal NLT. The correlation between symptom severity score and NLT findings was <0.16 (poor).

CONCLUSIONS

We have found evidence of OI, both symptomatically and haemodynamically in patients with LC. The severity of palpitations and dizziness reported on the C19-YRS does not appear to correlate with NLT findings. We would recommend using the NLT in all LC patients in a clinic setting, regardless of presenting LC symptoms, due to this inconsistency.

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.

Italian good practice recommendations on management of persons with Long-COVID

A significant number of people, following acute SARS-CoV-2 infection, report persistent symptoms or new symptoms that are sustained over time, often affecting different body systems. This condition, commonly referred to as Long-COVID, requires a complex clinical management. In Italy new health facilities specifically dedicated to the diagnosis and care of Long-COVID were implemented. However, the activity of these clinical centers is highly heterogeneous, with wide variation in the type of services provided, specialistic expertise and, ultimately, in the clinical care provided. Recommendations for a uniform management of Long-COVID were therefore needed. Professionals from different disciplines (including general practitioners, specialists in respiratory diseases, infectious diseases, internal medicine, geriatrics, cardiology, neurology, pediatrics, and odontostomatology) were invited to participate, together with a patient representative, in a multidisciplinary Panel appointed to draft Good Practices on clinical management of Long-COVID. The Panel, after extensive literature review, issued recommendations on 3 thematic areas: access to Long-COVID services, clinical evaluation, and organization of the services. The Panel highlighted the importance of providing integrated multidisciplinary care in the management of patients after SARS-CoV-2 infection, and agreed that a multidisciplinary service, one-stop clinic approach could avoid multiple referrals and reduce the number of appointments. In areas where multidisciplinary services are not available, services may be provided through integrated and coordinated primary, community, rehabilitation and mental health services. Management should be adapted according to the patient's needs and should promptly address possible life-threatening complications. The present recommendations could provide guidance and support in standardizing the care provided to Long-COVID patients.

Cerebral hypoperfusion in post-COVID-19 cognitively impaired subjects revealed by arterial spin labeling MRI

Cognitive impairment is one of the most prevalent symptoms of post Severe Acute Respiratory Syndrome COronaVirus 2 (SARS-CoV-2) state, which is known as Long COVID. Advanced neuroimaging techniques may contribute to a better understanding of the pathophysiological brain changes and the underlying mechanisms in post-COVID-19 subjects. We aimed at investigating regional cerebral perfusion alterations in post-COVID-19 subjects who reported a subjective cognitive impairment after a mild SARS-CoV-2 infection, using a non-invasive Arterial Spin Labeling (ASL) MRI technique and analysis. Using MRI-ASL image processing, we investigated the brain perfusion alterations in 24 patients (53.0 ± 14.5 years, 15F/9M) with persistent cognitive complaints in the post COVID-19 period. Voxelwise and region-of-interest analyses were performed to identify statistically significant differences in cerebral blood flow (CBF) maps between post-COVID-19 patients, and age and sex matched healthy controls (54.8 ± 9.1 years, 13F/9M). The results showed a significant hypoperfusion in a widespread cerebral network in the post-COVID-19 group, predominantly affecting the frontal cortex, as well as the parietal and temporal cortex, as identified by a non-parametric permutation testing (p < 0.05, FWE-corrected with TFCE). The hypoperfusion areas identified in the right hemisphere regions were more extensive. These findings support the hypothesis of a large network dysfunction in post-COVID subjects with cognitive complaints. The non-invasive nature of the ASL-MRI method may play an important role in the monitoring and prognosis of post-COVID-19 subjects.

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.

Prefrontal tDCS modulates autonomic responses in COVID-19 inpatients

BACKGROUND

maladaptive changes in the autonomic nervous system (ANS) have been observed in short and long-term phases of COVID-19 infection. Identifying effective treatments to modulate autonomic imbalance could be a strategy for preventing and reducing disease severity and induced complications.

OBJECTIVE

to investigate the efficacy, safety, and feasibility of a single session of bihemispheric prefrontal tDCS on indicators of cardiac autonomic regulation and mood of COVID-19 inpatients.

METHODS

patients were randomized to receive a single 30-minute session of bihemispheric active tDCS over the dorsolateral prefrontal cortex (2mA; n = 20) or sham (n = 20). Changes in time [post-pre intervention] in heart rate variability (HRV), mood, heart rate, respiratory rate, and oxygen saturation were compared between groups. Additionally, clinical worsening indicators and the occurrence of falls and skin injuries were evaluated. The Brunoni Adverse Effects Questionary was employed after the intervention.

RESULTS

there was a large effect size (Hedges' g = 0.7) of intervention on HRV frequency parameters, suggesting alterations in cardiac autonomic regulation. An increment in oxygen saturation was observed in the active group but not in the sham after the intervention (P = 0.045). There were no group differences regarding mood, incidence and intensity of adverse effects, no occurrence of skin lesions, falls, or clinical worsening.

CONCLUSIONS

a single prefrontal tDCS session is safe and feasible to modulate indicators of cardiac autonomic regulation in acute COVID-19 inpatients. Further research comprising a thorough assessment of autonomic function and inflammatory biomarkers is required to verify its potential to manage autonomic dysfunctions, mitigate inflammatory responses and enhance clinical outcomes.

The effects of COVID-19 on the vestibular system

Introduction

The symptoms and severity of SARS-CoV-2 infection vary greatly across the spectrum, from asymptomatic infection to severe pneumonia with acute respiratory distress syndrome and even death. Dizziness is a frequently reported symptom of SARS-CoV-2 viral infection. However, the extent to which this symptom results from the effect of SARS-CoV-2 on the vestibular system remains unclear.

Materials and methods

In the present single-center, prospective cohort study, patients with a previous SARS-CoV-2 infection underwent a vestibular assessment consisting of the Dizziness Handicap Inventory to assess dizziness during and after infection, a clinical examination, the video head impulse test, and the subjective visual vertical test. When the subjective visual vertical test result was abnormal, vestibular-evoked myogenic potentials were performed. Vestibular testing results were compared to pre-existing normative data of healthy controls. In addition, we performed a retrospective data analysis of patients admitted to hospital presenting with acute symptoms of dizziness who were also diagnosed with acute SARS-CoV-2 infection.

Results

A total of 50 participants have been enrolled. During and after the SARS-CoV-2 infection, women were significantly more likely than men to suffer from dizziness. A significantly reduced semicircular canal or otolith function was not observed in either women or men. Acute SARS-CoV-2 infection was diagnosed in nine patients who presented to the emergency room with acute vestibular syndrome. Six of the patients exhibited acute unilateral peripheral vestibulopathy upon diagnosis. A different patient was diagnosed with vestibular migraine, and two individuals had a posterior inferior cerebellar artery infarct revealed by magnetic resonance imaging.

Discussion/conclusion

Overall, a persisting structural affection of the vestibular system by SARS-CoV-2 seems to be unlikely and could not be confirmed by vHIT, SVV, and VEMPS in our study. It seems possible but unlikely that SARS-CoV-2 induces acute vestibulopathy. Nevertheless, dizziness is a common symptom in patients with COVID-19, which should be taken and worked through seriously.

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.

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.

Demonstrating new-onset or worsened sudomotor function post-COVID-19 on comparative analysis of autonomic function pre-and post-SARS-CoV-2 infection

Background

Autonomic dysfunction including sudomotor abnormalities have been reported in association with SARS-CoV-2 infection.

Objective

There are no previous studies that have compared autonomic function objectively in patients pre- and post- SARS-CoV-2 infection.We aimed to identify if SARS-CoV-2 virus is triggering and/or worsening dysautonomia by comparing autonomic function tests in a group of patients pre-and post-SARS-CoV-2 infection.

Design/methods

Six participants were enrolled and divided into two groups. The first group of 4 participants reported worsened autonomic symptoms post-SARS-CoV-2 infection. These individuals had their first autonomic test prior to COVID-19 pandemic outbreak (July 2019-December 2019). Autonomic function testing was repeated in these participants, 6 months to 1-year post-SARS-CoV-2 infection (June 2021).The second group of 2 participants reported new-onset autonomic symptoms post-COVID-19 infection and were also tested within 6 months post-SARS-CoV-2 infection.All participants had mild COVID-19 infection per WHO criteria. They had no evidence of large fiber neuropathy as demonstrated by normal neurophysiological studies (EMG/NCS). They were all screened for known causes of autonomic dysfunction and without risk factors of hypertension/hyperlipidemia, thyroid dysfunction, diabetes/prediabetes, vitamin deficiencies, history of HIV, hepatitis, or syphilis, prior radiation or chemical exposure or evidence of monoclonal gammopathy, or autoimmune condition.

Results

Participants were female (age: 21-37y) and all endorsed orthostatic intolerance (6/6). Gastrointestinal symptoms (⅚), new-onset paresthesias, (3/6), and sexual dysfunction (2/6) were reported. Parasympathetic autonomic function remained stable 6-months to 1-year post-COVID-19 infection and no parasympathetic dysfunction was demonstrated in participants with new-onset dysautonomia symptoms. Postural orthostatic tachycardia was noted in half of the patients, being observed in one patient pre- SARS-CoV-2 infection and persisting post-SARS-CoV-2 infection; while new-onset postural tachycardia was observed in 1/3rd of patients. Sympathetic cholinergic (sudomotor) dysfunction was demonstrated in ALL participants. Worsened, or new-onset, sudomotor dysfunction was demonstrated in those with mild or normal sudomotor function on pre-COVID-19 autonomic testing.

Conclusions

Sympathetic adrenergic and cholinergic dysautonomia probably account for some of the symptoms of Long COVID-19. Sudomotor dysfunction was demonstrated as consistently worsened or new-sequelae to COVID-19 infection. COVID-19 may be responsible for triggering new-onset or worsened small-fiber neuropathy in this sample, supporting previously reported studies with similar findings. However, the findings in our study are preliminary, and studies with larger sample size are needed to confirm these observations.

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.

Cognitive deficit in post-acute COVID-19: an opportunity for EEG evaluation?

BACKGROUND AND PURPOSE

Among the most common post-COVID symptoms, many patients experienced subjective cognitive deficit, commonly named "brain fog," that might be present also in those individuals without severe acute COVID-19 respiratory involvement. Some studies have investigated some of the mechanisms that might be associated with the brain fog with objective techniques including transcranial magnetic stimulation and neuroimaging.

METHODS

The aim of this study was to investigate the presence of electroencephalographic (EEG) alterations in people with post-COVID self-reported cognitive deficit.

RESULTS

Out of the 90 patients attending the post-COVID neurology ambulatory service, twenty patients presenting brain fog at least 4 weeks after acute non-severe COVID-19 infection, and without previous history of epilepsy, were investigated with 19-channel EEG, Montreal Cognitive Assessment (MoCA), and magnetic resonance imaging (MRI). EEG was found altered in 65% of the sample, among which 69% presented a slowing activity and 31% were characterized by epileptic discharges principally in the frontal areas. None of the patients showed DWI MRI lesions.

CONCLUSIONS

These findings highlight the usefulness of EEG analysis to objectively describe possible neurophysiological abnormalities in post-COVID patients presenting subjective cognitive deficit.