Nervous system consequences of COVID-19

Assessing the Impact of Post-COVID Clinics on 6-Month Health Care Utilization for Patients With Long COVID: A Single-Center Experience

Objective

To assess the impact of post-COVID clinics by examining the association between their early usage and downstream health care utilization.

Patients and Methods

In a case-control study spanning data from March 11, 2020 to June 1, 2023, patients with Long COVID were identified from a major health system using diagnosis codes. The Fast, Large-Scale Almost Matching Exactly algorithm was used to match patients who presented early to post-COVID clinics with patients with Long COVID who did not attend such clinics. Matching was performed on demographic characteristics, acute COVID severity, comorbidities, diagnosis date, and vaccination, to reduce confounders for the comparison of the health care utilization and mortality between cohorts.

Results

When exactly matching on all 46 features, the algorithm yielded 2814 matched patients, of whom 692 (24.6%; 66.6% females; mean [SD] age, 48.8 [14.5] years) were seen in post-COVID clinics within the first 6 months and 2122 (75.4%; 64.1% females; mean [SD] age, 49.7 [15.2] years) who were not. The average treatment effect (95% CI) of early post-COVID clinic usage was -0.60 (-0.83 to -0.39) on inpatient visits, -0.19 (-0.26 to -0.11) on emergency department visits, 7.62 (6.96-8.56) on outpatient visits, -$3467 (-$6267 to -$754) on estimated costs, and -0.006 (-0.010 to -0.003) on mortality.

Conclusion

Early usage of post-COVID clinics by patients with Long COVID is associated with not only fewer downstream inpatient stays, emergency department visits, estimated costs, and reduced mortality within the first 6 months but also greater outpatient utilization. Results suggest early post-COVID clinic involvement shifts care to outpatient settings, potentially reducing costs and mortality.

NETosis: A key player in autoimmunity, COVID-19, and long COVID

NETosis, the process through which neutrophils release neutrophil extracellular traps (NETs), has emerged as a crucial mechanism in host defense and the pathogenesis of autoimmune responses. During the SARS-CoV-2 pandemic, this process received significant attention due to the central role of neutrophil recruitment and activation in infection control. However, elevated neutrophil levels and dysregulated NET formation have been linked to coagulopathy and endothelial damage, correlating with disease severity and poor prognosis in COVID-19. Moreover, it is known that SARS-CoV-2 can induce persistent low-grade systemic inflammation, known as long COVID, although the underlying causes remain unclear. It has been increasingly acknowledged that excessive NETosis and NET generation contribute to further pathophysiological abnormalities following SARS-CoV-2 infection. This review provides an updated overview of the role of NETosis in autoimmune diseases, but also the relationship between COVID-19 and long COVID with autoimmunity (e.g., latent and overt autoimmunity, molecular mimicry, epitope spreading) and NETosis (e.g., immune responses, NET markers). Finally, we discuss potential therapeutic strategies targeting dysregulated NETosis to mitigate the severe complications of COVID-19 and long COVID.

SARS-CoV2 infection triggers inflammatory conditions and astrogliosis-related gene expression in long-term human cortical organoids

SARS-CoV2, severe acute respiratory syndrome coronavirus 2, is frequently associated with neurological manifestations. Despite the presence of mild to severe CNS-related symptoms in a cohort of patients, there is no consensus whether the virus can infect directly brain tissue or if the symptoms in patients are a consequence of peripheral infectivity of the virus. Here, we use long-term human stem cell-derived cortical organoids to assess SARS-CoV2 infectivity of brain cells and unravel the cell-type tropism and its downstream pathological effects. Our results show consistent and reproducible low levels of SARS-CoV2 infection of astrocytes, deep projection neurons, upper callosal neurons, and inhibitory neurons in 6 months of human cortical organoids. Interestingly, astrocytes showed the highest infection rate among all infected cell populations which led to changes in their morphology and upregulation of SERPINA3, CD44, and S100A10 astrogliosis markers. Further, transcriptomic analysis revealed overall changes in expression of genes related to cell metabolism, astrogliosis and, inflammation and further, upregulation of cell survival pathways. Thus, local and minor infectivity of SARS-CoV2 in the brain may induce widespread adverse effects and lead to the resilience of dysregulated neurons and astrocytes within an inflammatory environment.

Exploring the role of mitochondrial dysfunction and aging in COVID-19-Related neurological complications

The COVID-19 pandemic, caused by SARS-CoV-2, posed a tremendous challenge to healthcare systems globally. Severe COVID-19 infection was reported to be associated with altered immunometabolism and cytokine storms, contributing to poor clinical outcomes and in many cases resulting in mortality. Despite promising preclinical results, many drugs have failed to show efficacy in clinical trials, highlighting the need for novel approaches to combat the virus and its severe manifestations. Mitochondria, crucial for aerobic respiration, play a pivotal role in modulating immunometabolism and neuronal function, making their compromised capability as central pathological mechanism contributing to the development of neurological complications in COVID-19. Dysregulated mitochondrial dynamics can lead to uncontrolled immune responses, underscoring the importance of mitochondrial regulation in shaping clinical outcomes. Aging further accelerates mitochondrial dysfunction, compounding immune dysregulation and neurodegeneration, making older adults particularly vulnerable to severe COVID-19 and its neurological sequelae. COVID-19 infection impairs mitochondrial oxidative phosphorylation, contributing to the long-term neurological complications associated with the disease. Additionally, recent reports also suggest that up to 30% of COVID-19 patients experience lingering neurological issues, thereby highlighting the critical need for further research into mitochondrial pathways to mitigate long-tern neurological consequences of Covid-19. This review examines the role of mitochondrial dysfunction in COVID-19-induced neurological complications, its connection to aging, and potential biomarkers for clinical diagnostics. It also discusses therapeutic strategies aimed at maintaining mitochondrial integrity to improve COVID-19 outcomes.

The key role of the ferroptosis mechanism in neurological diseases and prospects for targeted therapy

Neurological disorders represent a major global health concern owing to their intricate pathological processes. Ferroptosis, defined as a form of cell death that is reliant on iron, has been closely linked to various neurological conditions. The fundamental process underlying ferroptosis is defined by the excessive buildup of iron ions, which initiates lipid peroxidation processes leading to cellular demise. Neurons, as highly metabolically active cells, are susceptible to oxidative stress, and imbalances in iron metabolism can directly initiate the ferroptosis process. In neurodegenerative disorders like Alzheimer's disease and Parkinson's disease, ferroptosis driven by iron accumulation represents a fundamental pathological connection. Although the connection between ferroptosis and neurological diseases is clear, clinical application still faces challenges, such as precise regulation of iron metabolism, development of specific drugs, and assessment of efficacy. The limited comprehension of the ferroptosis mechanism hinders the development of personalized treatment approaches. Consequently, subsequent investigations must tackle these obstacles to facilitate the clinical application of ferroptosis-associated therapies in neurological disorders. This article provides a comprehensive overview of the most recent advancements regarding the underlying mechanisms of ferroptosis. Subsequently, the study investigates the mechanistic contributions of ferroptosis within the nervous system. In conclusion, we evaluate and deliberate on targeted therapeutic strategies associated with ferroptosis and neurological disorders.

Need for awareness and surveillance of long-term post-COVID neurodegenerative disorders. A position paper from the neuroCOVID-19 task force of the European Academy of Neurology

BACKGROUND

Neuropathological and clinical studies suggest that infection with SARS-CoV-2 may increase the long-term risk of neurodegeneration.

METHODS

We provide a narrative overview of pathological and clinical observations justifying the implementation of a surveillance program to monitor changes in the incidence of neurodegenerative disorders in the years after COVID-19.

RESULTS

Autopsy studies revealed diverse changes in the brain, including loss of vascular integrity, microthromboses, gliosis, demyelination, and neuronal- and glial injury and cell death, in both unvaccinated and vaccinated individuals irrespective of the severity of COVID-19. Recent data suggest that microglia play an important role in sustained COVID-19-related inflammation, which contributes to the etiology initiating a neurodegenerative cascade, to the worsening of pre-existing neurodegenerative disease or to the acceleration of neurodegenerative processes. Histopathological data have been supported by neuroimaging, and epidemiological studies also suggested a higher risk for neurodegenerative diseases after COVID-19.

CONCLUSIONS

Due to the high prevalence of COVID-19 during the pandemic, healthcare systems should be aware of, and be prepared for a potential increase in the incidence of neurodegenerative diseases in the upcoming years. Strategies may include follow-up of well-described cohorts, analyses of outcomes in COVID-19-registries, nationwide surveillance programs using record-linkage of ICD-10 diagnoses, and comparing the incidence of neurodegenerative disorders in the post-pandemic periods to values of the pre-pandemic years. Awareness and active surveillance are particularly needed, because diverse clinical manifestations due to earlier SARS-CoV-2 infections may no longer be quoted as post-COVID-19 symptoms, and hence, increasing incidence of neurodegenerative pathologies at the community level may remain unnoticed.

Virtual Reality-Based Infrared Pupillometry (VIP) for Long-COVID

PURPOSE

To evaluate the use of virtual reality-based infrared pupillometry (VIP) to detect individuals with long coronavirus disease (LCVD).

DESIGN

Prospective, case-control cross-sectional study.

PARTICIPANTS

Participants 20 to 60 years of age were recruited from a community eye screening program.

METHODS

Pupillary light responses (PLRs) were recorded in response to 3 intensities of light stimuli (L6, L7, and L8) using a virtual reality head-mount display (VRHMD). Nine PLR waveform features for each stimulus were extracted by 2 masked observers and were analyzed statistically. We also used trained, validated, and tested (6:3:1) methods on the entire PLR waveform by machine learning models for 2-class and 3-class classification into LCVD, post-COVID (PCVD), or control groups.

MAIN OUTCOME MEASURES

Accuracies and areas under the receiver operating characteristic curve (AUCs) of individual or a combination of PLR features and machine learning models analyzing PLR features or whole pupillometric waveform.

RESULTS

Pupillary light responses from a total of 185 participants, including 112 in the LCVD group, 44 in the PCVD group, and 29 in the age- and sex-matched control group were analyzed. Models examined the independent effects of age and sex. Constriction time (CT) after the brightest stimulus (L8) is associated significantly with LCVD status (false discovery rate [FDR] < 0.001, 2-way analysis of variance; FDR < 0.05, multinominal logistic regression). The overall accuracy and AUC of CT after L8 alone in differentiating the LCVD group from the control or PCVD group were 0.7808 and 0.8711, respectively, and 0.8654 and 0.8140, respectively. Using cross-validated backward stepwise variable selection, CT after L8, CT after L6, and constriction velocity (CV) after L6 were most useful to detect LCVD, whereas CV after L8 was most useful for distinguishing the PCVD group from other groups. The accuracy and AUC of selected features were 0.8000 and 0.9000 (control vs. LCVD groups) and 0.9062 and 0.9710 (PCVD vs. LCVD groups), respectively, better than when all 27 pupillometric features were combined. A long short-term memory model analyzing whole pupillometric waveform achieved the highest accuracy and AUC at 0.9375 and 1.000 in differentiating the LCVD from PCVD group and a lower accuracy of 0.7838 for 3-class classification (LCVD, PCVD, and control group).

CONCLUSIONS

We report specific pupillometric signatures in differentiating LCVD from PCVD or control groups using a VRHMD. Combining statistical methods to identify specific pupillometric features and machine learning algorithms to analyze the whole pupillometric waveform further enhanced the performance of VIP as a nonintrusive, low-cost, portable, and objective method to detect LCVD.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Spike protein-related proteinopathies: A focus on the neurological side of spikeopathies

BACKGROUND

The spike protein (SP) is an outward-projecting transmembrane glycoprotein on viral surfaces. SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2), responsible for COVID-19 (Coronavirus Disease 2019), uses SP to infect cells that express angiotensin converting enzyme 2 (ACE2) on their membrane. Remarkably, SP has the ability to cross the blood-brain barrier (BBB) into the brain and cause cerebral damage through various pathomechanisms. To combat the COVID-19 pandemic, novel gene-based products have been used worldwide to induce human body cells to produce SP to stimulate the immune system. This artificial SP also has a harmful effect on the human nervous system.

STUDY DESIGN

Narrative review.

OBJECTIVE

This narrative review presents the crucial role of SP in neurological complaints after SARS-CoV-2 infection, but also of SP derived from novel gene-based anti-SARS-CoV-2 products (ASP).

METHODS

Literature searches using broad terms such as "SARS-CoV-2", "spike protein", "COVID-19", "COVID-19 pandemic", "vaccines", "COVID-19 vaccines", "post-vaccination syndrome", "post-COVID-19 vaccination syndrome" and "proteinopathy" were performed using PubMed. Google Scholar was used to search for topic-specific full-text keywords.

CONCLUSIONS

The toxic properties of SP presented in this review provide a good explanation for many of the neurological symptoms following SARS-CoV-2 infection and after injection of SP-producing ASP. Both SP entities (from infection and injection) interfere, among others, with ACE2 and act on different cells, tissues and organs. Both SPs are able to cross the BBB and can trigger acute and chronic neurological complaints. Such SP-associated pathologies (spikeopathies) are further neurological proteinopathies with thrombogenic, neurotoxic, neuroinflammatory and neurodegenerative potential for the human nervous system, particularly the central nervous system. The potential neurotoxicity of SP from ASP needs to be critically examined, as ASPs have been administered to millions of people worldwide.

Long-COVID and postural orthostatic tachycardia syndrome: a preliminary comparison of neuropsychological performance

PURPOSE

The aim of the study is to analyze and compare the cognitive profile between 59 patients with long-COVID [LC; 30 of them with and 29 without a positive coronavirus disease 2019 (COVID-19) confirmatory test] and 31 patients with postural orthostatic tachycardia syndrome (POTS) and a matched group of 39 healthy control participants.

METHODS

Participants were examined on a battery of neuropsychological tests, including verbal memory, visuospatial abilities, attention, processing speed, verbal fluency, working memory, and visual memory. Anxious-depressive symptomatology was also analyzed and then controlled for possible influence on cognitive performance.

RESULTS

Patients with LC and POTS showed significantly lower performance compared with healthy peers. Differences on anxious and depressive symptoms were also found between the clinical and control groups, resulting in LC without a positive confirmatory test group exhibiting the highest rates of anxious symptoms. After controlling the effects of anxious-depressive symptomatology, the differences were eliminated for some of the cognitive variables, but additional differences were found between patients with LC and POTS after post hoc analysis.

CONCLUSIONS

Findings from the present study contribute toward the reinforcement of the evidence on cognitive alterations associated with LC and POTS. Anxious-depressive symptomatology has to be considered in both clinical groups since it could be affecting cognitive performance.

Nasal Spray Disinfectant for Respiratory Infections Based on Functionalized Silver Nanoparticles: A Physicochemical and Docking Approach

Respiratory diseases have presented a remarkable challenge during modern history, contributing to important pandemics. The scientific community has focused its efforts on developing vaccines and blocking the transmission of viruses through the respiratory tract. In this study, we propose the use of stable silver nanoparticles (AgNPs) functionalized with tannic acid (TA) and sodium citrate (SC) as a nasal spray disinfectant (NSD). The non-ionic ethoxylated surfactant Tween 80 (T80) was added to enhance the wetting effect on nasal and oral tissues following spray application. We analyzed the physicochemical properties of the AgNPs and the NSD, including zeta potential, polarity, morphology, composition, particle size, and distribution. The results indicated spherical AgNPs ranging from 3 to 5 nm, stabilized by TA-SC. The addition of T80 resulted in particles with negative polarity, high stability, and improved coverage area. Furthermore, the colloidal stability was monitored over one year, showing no signs of degradation or precipitation. Interestingly, the interaction between the capped AgNP complex, the spike protein, and ACE2 was studied by molecular docking, indicating a strong and thermodynamically favorable complex interaction. These findings hold promise for the development of potential inhibitors, antagonist receptors, Ag-complex agonists (as observed here), and drug development for viral protection.

Serotonergic psychedelics as potential therapeutics for post-COVID-19 syndrome (or Long COVID): A comprehensive review

RATIONALE

In our ongoing battle against the coronavirus 2019 (COVID-19) pandemic, a major challenge is the enduring symptoms that continue after acute infection. Also known as Long COVID, post-COVID-19 syndrome (PCS) often comes with debilitating symptoms like fatigue, disordered sleep, olfactory dysfunction, and cognitive issues ("brain fog"). Currently, there are no approved treatments for PCS. Recent research has uncovered that the severity of PCS is inversely linked to circulating serotonin levels, highlighting the potential of serotonin-modulating therapeutics for PCS. Therefore, we propose that serotonergic psychedelics, acting mainly via the 5-HT2A serotonin receptor, hold promise for treating PCS.

OBJECTIVES

Our review aims to elucidate potential mechanisms by which serotonergic psychedelics may alleviate the symptoms of PCS.

RESULTS

Potential mechanisms through which serotonergic psychedelics may alleviate PCS symptoms are discussed, with emphasis on their effects on inflammation, neuroplasticity, and gastrointestinal function. Additionally, this review explores the potential of serotonergic psychedelics in mitigating endothelial dysfunction, a pivotal aspect of PCS pathophysiology implicated in organ dysfunction. This review also examines the potential role of serotonergic psychedelics in alleviating specific PCS symptoms, which include olfactory dysfunction, cognitive impairment, sleep disturbances, and mental health challenges.

CONCLUSIONS

Emerging evidence suggests that serotonergic psychedelics may alleviate PCS symptoms. However, further high-quality research is needed to thoroughly assess their safety and efficacy in treating patients with PCS.

Neuropsychiatric sequelae in an experimental model of post-COVID syndrome in mice

The global impact of the COVID-19 pandemic has been unprecedented, and presently, the world is facing a new challenge known as post-COVID syndrome (PCS). Current estimates suggest that more than 100 million people are grappling with PCS, encompassing several manifestations, including pulmonary, musculoskeletal, metabolic, and neuropsychiatric sequelae (cognitive and behavioral). The mechanisms underlying PCS remain unclear. The present study aimed to: (i) comprehensively characterize the acute effects of pulmonary inoculation of the betacoronavirus MHV-A59 in immunocompetent mice at clinical, cellular, and molecular levels; (ii) examine potential acute and long-term pulmonary, musculoskeletal, and neuropsychiatric sequelae induced by the betacoronavirus MHV-A59; and to (iii) assess sex-specific differences. Male and female C57Bl/6 mice were initially inoculated with varying viral titers (3x103 to 3x105 PFU/30 μL) of the betacoronavirus MHV-A59 via the intranasal route to define the highest inoculum capable of inducing disease without causing mortality. Further experiments were conducted with the 3x104 PFU inoculum. Mice exhibited an altered neutrophil/lymphocyte ratio in the blood in the 2nd and 5th day post-infection (dpi). Marked lung lesions were characterized by hyperplasia of the alveolar walls, infiltration of polymorphonuclear leukocytes (PMN) and mononuclear leukocytes, hemorrhage, increased concentrations of CCL2, CCL3, CCL5, and CXCL1 chemokines, as well as high viral titers until the 5th dpi. While these lung inflammatory signs resolved, other manifestations were observed up to the 60 dpi, including mild brain lesions with gliosis and hyperemic blood vessels, neuromuscular dysfunctions, anhedonic-like behavior, deficits in spatial working memory, and short-term aversive memory. These musculoskeletal and neuropsychiatric complications were exclusive to female mice and prevented after ovariectomy. In summary, our study describes for the first time a novel sex-dependent model of PCS focused on neuropsychiatric and musculoskeletal disorders. This model provides a unique platform for future investigations regarding the effects of acute therapeutic interventions on the long-term sequelae unleashed by betacoronavirus infection.

Psychiatric and neuropsychiatric sequelae of COVID-19 within 2 years: a multinational cohort study

BACKGROUND

The long-term psychiatric and neuropsychiatric sequelae of COVID-19 across diverse populations remain not fully understood. This cohort study aims to investigate the short-, medium-, and long-term risks of psychiatric and neuropsychiatric disorders following COVID-19 infection in five countries.

METHODS

This population-based multinational network study used electronic medical records from France, Italy, Germany, and the UK and claims data from the USA. The initial target and comparator cohorts were identified using an exact matching approach based on age and sex. Individuals diagnosed with COVID-19 or those with a positive SARS-CoV-2 screening test between December 1, 2019, and December 1, 2020, were included as targets. Up to ten comparators without COVID-19 for each target were selected using the propensity score matching approach. All individuals were followed from the index date until the end of continuous enrolment or the last healthcare encounter. Cox proportional hazard regression models were fitted to estimate the risk of incident diagnosis of depression, anxiety disorders, alcohol misuse or dependence, substance misuse or dependence, bipolar disorders, psychoses, personality disorders, self-harm and suicide, sleep disorders, dementia, and neurodevelopmental disorders within the first 6 months (short-term), 6 months to 1 year (medium-term), and 1 to 2 years (long-term) post-infection.

RESULTS

A total of 303,251 individuals with COVID-19 and 22,108,925 individuals without COVID-19 from five countries were originally included. Within the first 6 months, individuals with COVID-19 had a significantly higher risk of any studied disorders in all databases, with Hazard Ratios (HRs) ranging from 1.14 (95% CI, 1.07-1.22) in Germany to 1.89 (1.64-2.17) in Italy. Increased risks were consistently observed for depression, anxiety disorders, and sleep disorders across almost all countries. During the medium- and long-term periods, higher risks were observed only for depression (medium-term: 1.29, 1.18-1.41; long-term: 1.36, 1.25-1.47), anxiety disorders (medium-term: 1.29, 1.20-1.38; long-term: 1.37, 1.29-1.47), and sleep disorders (medium-term: 1.10, 1.01-1.21; long-term: 1.14, 1.05-1.24) in France, and dementia (medium-term: 1.65, 1.28-2.10) in the UK.

CONCLUSIONS

Our study suggests that increased risks of psychiatric and neuropsychiatric outcomes were consistently observed only within, and not after, the 6-month observation period across all databases, except for certain conditions in specific countries.

Post-COVID major depression is not associated with peripheral inflammation

INTRODUCTION

Although post-COVID major depressive disorder (MDD) is frequent, the physiological mechanisms associated with it remain unclear. This study aimed to assess the association between 10 residual blood markers of inflammation and the presence of MDD 4 months after the acute phase of COVID-19.

METHODS

This is a cross-sectional study of the COMEBAC cohort that followed patients 4 months after hospitalization for COVID-19 at Bicêtre Hospital. Patients with lingering symptoms or who had been in critical care (n = 177) were invited to a day hospital for assessment of MDD and peripheral inflammation. Ten peripheral inflammatory markers were examined: plasmatic C-reactive protein; leukocyte, monocyte, neutrophil, and lymphocyte counts; the neutrophil to lymphocyte ratio; the systemic inflammatory index (i.e., the (platelet x neutrophil) to lymphocyte ratio); cortisol, ferritin, and hemoglobin levels. Current MDD was assessed through structured interviews with a psychiatrist, depressive symptoms through self-questionnaires. Peripheral inflammatory markers were compared between patients with post-COVID MDD and patients without a lifetime history of psychiatric disorders (controls).

RESULTS

Out of 177 patients, 24 (13.6%) had MDD. No significant differences in peripheral inflammatory markers were observed between patients with post-COVID MDD and controls. Furthermore, peripheral inflammatory markers were not correlated with symptoms of depression.

CONCLUSION

We found no association between post-COVID MDD and 10 peripheral inflammatory markers 4 months after COVID-19 infection. Other potential mechanisms warrant investigation.

Microglia dysfunction, neurovascular inflammation and focal neuropathologies are linked to IL-1- and IL-6-related systemic inflammation in COVID-19

COVID-19 is associated with diverse neurological abnormalities, but the underlying mechanisms are unclear. We hypothesized that microglia, the resident immune cells of the brain, are centrally involved in this process. To study this, we developed an autopsy platform allowing the integration of molecular anatomy, protein and mRNA datasets in postmortem mirror blocks of brain and peripheral organ samples from cases of COVID-19. We observed focal loss of microglial P2Y12R, CX3CR1-CX3CL1 axis deficits and metabolic failure at sites of virus-associated vascular inflammation in severely affected medullary autonomic nuclei and other brain areas. Microglial dysfunction is linked to mitochondrial injury at sites of excessive synapse and myelin phagocytosis and loss of glutamatergic terminals, in line with proteomic changes of synapse assembly, metabolism and neuronal injury. Furthermore, regionally heterogeneous microglial changes are associated with viral load and central and systemic inflammation related to interleukin (IL)-1 or IL-6 via virus-sensing pattern recognition receptors and inflammasomes. Thus, SARS-CoV-2-induced inflammation might lead to a primarily gliovascular failure in the brain, which could be a common contributor to diverse COVID-19-related neuropathologies.

Emerging and re-emerging viral infections of the central nervous system in Australasia and beyond

Viral infections of the central nervous system (CNS) have been emerging and re-emerging worldwide, and the Australasia region has not been spared. Enterovirus A71 and enterovirus D68, both human enteroviruses, are likely to replace the soon-to-be eradicated poliovirus to cause global outbreaks associated with neurological disease. Although prevalent elsewhere, the newly emergent orthoflavivirus, Japanese encephalitis virus (genotype IV), caused human infections in Australia in 2021, and almost certainly will continue to do so because of spillovers from the natural animal host-vector life cycle endemic in the country. Another orthoflavivirus, Murray Valley encephalitis virus, has re-emerged in Australia. The Hendra henipavirus together with Nipah henipavirus ​are listed as high-risk pathogens by the World Health Organization because both can cause lethal encephalitis. The former remains a health threat in Australasia because bats may still be able to spread the infection to unvaccinated Australian horses and other animals acting as intermediate hosts, and thence to humans. The global COVID-19 pandemic, caused by the emerging severe acute respiratory syndrome coronavirus-2, a virus transmitted from animals to humans that was first described and first arose in China, is associated with acute and long-lasting CNS pathology. Fortunately, the pathology and pathogenesis of these important neurotropic viruses are now better understood, leading to better management protocols and prevention strategies. Pathologists are in a unique position to contribute to the diagnosis and advancement in our knowledge of infectious diseases. This review summarises some of the current knowledge about a few important emerging and re-emerging CNS infections in Australasia and beyond.

Objectifying persistent subjective cognitive impairment following COVID-19 infection: cross-sectional data from an outpatient memory-clinic in Germany

OBJECTIVE

Subjective cognitive impairment is frequently reported by patients experiencing Post-COVID symptoms. This study aims to assess objective impairment in attention, memory, and executive functions among these patients. Further, we investigated potential determinants of objective cognitive impairment.

METHODS

In this cross-sectional study, standardized neuropsychological testing (Vienna Testing System), assessment of cognitive symptom aggravation, psychiatric anamnesis, and psychometrics (BDI-II, Fatigue Severity Scale) were conducted in 229 patients who voluntarily presented to our outpatient memory-clinic due to subjective cognitive impairment following COVID-19. Blood-samples were collected to assess peripheral immune markers (IL-6, CRP) and APOE-ε4 genotype.

RESULTS

Objective cognitive impairment in at least one domain was present in 39% of the patients and 47% showed symptoms of moderate or severe depression. The APOE-ε4 allele was present in 32% of the patients. Higher rates of depressive symptoms (OR = 1.41, 95%-CI = 1.02-1.95) and higher burden of the APOE-ε4 allele (OR = 3.29, 95%-CI = 1.51-7.40) predicted objective cognitive impairment, regardless of age, sex, years of formal education, time since infection, and medication for diabetes or hypertension. Fatigue severity, acute COVID-19 severity or inflammation markers had no impact.

CONCLUSIONS

In our study, subjective cognitive impairment following COVID-19 was more likely associated with high rates of depression rather than relatively low rates of objective cognitive performance. Thus, the study emphasizes the necessity for extensive neuropsychological testing and evaluation of depression when examining Post-COVID patients in clinical practice. Further, the link between objective cognitive impairment, depression and APOE-ε4 does not appear to be specific to Post-COVID symptoms. Therefore, depression- and APOE-ε4-mediated neurodegenerative pathomechanisms might be a promising therapeutical target.

Negative Framing of COVID-19 Information Affects Older Adults' Memory Function

Stereotype threat occurs when negative stereotypes about one's group increase cognitive load, impairing functioning in line with the stereotype. Cognitive and neurological symptoms of COVID-19 may be salient and worrisome to older adults as these functions are key to independence. We examined whether presenting adverse age-related information about COVID-19 invokes stereotype threat and impacts cognitive performance on a subsequent task. Older adults (59+), recruited online, read either neutral or negative age-related COVID-19 information. Participants then completed a word recognition task. The threat group had significantly worse memory performance compared to the neutral group even after controlling for age and history of COVID-19 diagnosis. Simply reading information about COVID-19 may pose a threat to older adults' cognitive abilities. Our results highlight the far-reaching effects of the pandemic beyond experiencing symptoms of the disease and how the framing of health-related information can have negative consequences for older adults' cognition.

Direct effects of prolonged TNF-α and IL-6 exposure on neural activity in human iPSC-derived neuron-astrocyte co-cultures

Cognitive impairment is one of the many symptoms reported by individuals suffering from long-COVID and other post-viral infection disorders such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). A common factor among these conditions is a sustained immune response and increased levels of inflammatory cytokines. Tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) are two such cytokines that are elevated in patients diagnosed with long-COVID and ME/CFS. In this study, we characterized the changes in neural functionality, secreted cytokine profiles, and gene expression in co-cultures of human iPSC-derived neurons and primary astrocytes in response to prolonged exposure to TNF-α and IL-6. We found that exposure to TNF-α produced both a concentration-independent and concentration-dependent response in neural activity. Burst duration was significantly reduced within a few days of exposure regardless of concentration (1 pg/mL - 100 ng/mL) but returned to baseline after 7 days. Treatment with low concentrations of TNF-α (e.g., 1 and 25 pg/mL) did not lead to changes in the secreted cytokine profile or gene expression but still resulted in significant changes to electrophysiological features such as interspike interval and burst duration. Conversely, treatment with high concentrations of TNF-α (e.g., 10 and 100 ng/mL) led to reduced spiking activity, which may be correlated to changes in neural health, gene expression, and increases in inflammatory cytokine secretion (e.g., IL-1β, IL-4, and CXCL-10) that were observed at higher TNF-α concentrations. Prolonged exposure to IL-6 led to changes in bursting features, with significant reduction in the number of spikes in bursts across a wide range of treatment concentrations (i.e., 1 pg/mL-10 ng/mL). In combination, the addition of IL-6 appears to counteract the changes to neural function induced by low concentrations of TNF-α, while at high concentrations of TNF-α the addition of IL-6 had little to no effect. Conversely, the changes to electrophysiological features induced by IL-6 were lost when the cultures were co-stimulated with TNF-α regardless of the concentration, suggesting that TNF-α may play a more pronounced role in altering neural function. These results indicate that increased concentrations of key inflammatory cytokines associated with long-COVID can directly impact neural function and may be a component of the cognitive impairment associated with long-COVID and other post-viral infection disorders.

Immunologic and inflammatory consequences of SARS-CoV-2 infection and its implications in renal disease

The emergence of the COVID-19 pandemic made it critical to understand the immune and inflammatory responses to the SARS-CoV-2 virus. It became increasingly recognized that the immune response was a key mediator of illness severity and that its mechanisms needed to be better understood. Early infection of both tissue and immune cells, such as macrophages, leading to pyroptosis-mediated inflammasome production in an organ system critical for systemic oxygenation likely plays a central role in the morbidity wrought by SARS-CoV-2. Delayed transcription of Type I and Type III interferons by SARS-CoV-2 may lead to early disinhibition of viral replication. Cytokines such as interleukin-1 (IL-1), IL-6, IL-12, and tumor necrosis factor α (TNFα), some of which may be produced through mechanisms involving nuclear factor kappa B (NF-κB), likely contribute to the hyperinflammatory state in patients with severe COVID-19. Lymphopenia, more apparent among natural killer (NK) cells, CD8+ T-cells, and B-cells, can contribute to disease severity and may reflect direct cytopathic effects of SARS-CoV-2 or end-organ sequestration. Direct infection and immune activation of endothelial cells by SARS-CoV-2 may be a critical mechanism through which end-organ systems are impacted. In this context, endovascular neutrophil extracellular trap (NET) formation and microthrombi development can be seen in the lungs and other critical organs throughout the body, such as the heart, gut, and brain. The kidney may be among the most impacted extrapulmonary organ by SARS-CoV-2 infection owing to a high concentration of ACE2 and exposure to systemic SARS-CoV-2. In the kidney, acute tubular injury, early myofibroblast activation, and collapsing glomerulopathy in select populations likely account for COVID-19-related AKI and CKD development. The development of COVID-19-associated nephropathy (COVAN), in particular, may be mediated through IL-6 and signal transducer and activator of transcription 3 (STAT3) signaling, suggesting a direct connection between the COVID-19-related immune response and the development of chronic disease. Chronic manifestations of COVID-19 also include systemic conditions like Multisystem Inflammatory Syndrome in Children (MIS-C) and Adults (MIS-A) and post-acute sequelae of COVID-19 (PASC), which may reflect a spectrum of clinical presentations of persistent immune dysregulation. The lessons learned and those undergoing continued study likely have broad implications for understanding viral infections' immunologic and inflammatory consequences beyond coronaviruses.

A network medicine approach to investigating ME/CFS pathogenesis in severely ill patients: a pilot study

This pilot study harnessed the power of network medicine to unravel the complex pathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). By utilizing a network analysis on whole genome sequencing (WGS) data from the Severely Ill Patient Study (SIPS), we identified ME/CFS-associated proteins and delineated the corresponding network-level module, termed the SIPS disease module, together with its relevant pathways. This module demonstrated significant overlap with genes implicated in fatigue, cognitive disorders, and neurodegenerative diseases. Our pathway analysis revealed potential associations between ME/CFS and conditions such as COVID-19, Epstein-Barr virus (EBV) infection, neurodegenerative diseases, and pathways involved in cortisol synthesis and secretion, supporting the hypothesis that ME/CFS is a neuroimmune disorder. Additionally, our findings underscore a potential link between ME/CFS and estrogen signaling pathways, which may elucidate the higher prevalence of ME/CFS in females. These findings provide insights into the pathogenesis of ME/CFS from a network medicine perspective and highlight potential therapeutic targets. Further research is needed to validate these findings and explore their implications for improving diagnosis and treatment.

Animal Models for Long COVID: Current Advances, Limitations, and Future Directions

Long COVID (LC) represents a chronic, systemic, and often disabling condition that poses a significant ongoing threat to public health. Foundational scientific studies are needed to unravel the underlying mechanisms, with the ultimate goal of developing effective preventative and therapeutic strategies. Therefore, there is an urgent demand for animal models that can accurately replicate the clinical features of LC. This review integrates clinical epidemiological data to summarize the pathological changes in extrapulmonary systems involved in LC. Additionally, it critically examines the capacity of existing animal models, including nonhuman primates, genetically modified mice, and Syrian hamsters, to exhibit enduring postinfection symptoms that align with human clinical manifestations, and identifies key areas requiring further development. The objective is to offer insights that will aid in the development of next-generation animal models, thereby accelerating our understanding of how acute respiratory viral infections transition into chronic conditions, and ensuring preparedness for future pandemics.

Subphenotypes of Long COVID and the clinical applications of probiotics

As the number of infections and deaths attributable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection continues to rise, it is now becoming apparent that the health impacts of the Coronavirus disease (COVID-19) may not be limited to infection and the subsequent resolution of symptoms. Reports have shown that patients with SARS-CoV-2 infection may experience multiple symptoms across different organ systems that are associated with adverse health outcomes and develop new cardiac, renal, respiratory, musculoskeletal, and nervous conditions, a condition known as Long COVID or the post-acute sequelae of COVID-19 (PASC). This review provides insights into distinct subphenotypes of Long COVID and identifies microbiota dysbiosis as a common theme and crucial target for future therapies. Another important finding is that Long COVID is associated with prolonged and increased inflammation, potentially attributable to immune system dysfunction. A promising solution lies in the potential of probiotics to mitigate Long COVID symptoms by restoring gut microbiota balance and modulating the immune response. By evaluating the current clinical development landscape of the use of probiotics to treat Long COVID symptoms, this paper provides recommendations for future research by stressing the need to understand the modulation of bacterium strains followed by probiotic therapy to understand the association of microbiota dysbiosis with Long COVID symptoms. This will facilitate the development of effective probiotic formulations that could serve as reliable therapies against Long COVID.

Neuroinvasion via Peripheral Nerves in Epidemic Viral Encephalitis Caused by Enterovirus, Orthoflavivirus and SARS-Coronavirus

Pathogens invade the central nervous system (CNS) and cause infections either through the haematogenous route or via peripheral nerves. Neuroinvasion via peripheral nerves, involving spinal or cranial somatic nerves, is well-established for certain viral encephalitides such as rabies, herpes simplex encephalitis, and poliomyelitis. Advances in understanding emerging and re-emerging viruses that cause epidemic CNS infections have highlighted the growing importance of peripheral nerve pathways in viral neuroinvasion. This review focuses on epidemic viral encephalitides caused by three groups of RNA viruses, viz., enteroviruses (enterovirus A71 and enterovirus D68), orthoflaviviruses (West Nile virus and Japanese encephalitis virus), and severe acute respiratory syndrome coronaviruses (mainly severe acute respiratory coronavirus-2). We examine evidence supporting the hypothesis that peripheral nerve viral transmission may play an increasingly significant if not more critical role than the haematogenous route in neuroinvasion.

Post-COVID-19 conditions and health effects in Africa: a scoping review

INTRODUCTION

The SARS-CoV-2 pandemic has caused global devastations in social, economic and health systems of every nation, but disproportionately of nations in Africa. In addition to its grave effects on the global systems, there is continuation or development of new symptoms among individuals who have contracted the virus, with the potential to further stress the health systems on the continent. Therefore, the aim of this scoping review was to collate and summarise the existing research evidence on the prevalence and health effects of post-COVID-19 conditions in Africa.

METHODS AND ANALYSIS

Five main databases were thoroughly searched from 1 September 2023 to 10 May 2024 for eligible articles based on the pre-established inclusion and exclusion criteria. These databases included PubMed, Central, Scopus, Dimensions AI and JSTOR. A total of 17 papers were included in the review. The protocol for this review is already published in BMJ Open; doi:10.1136/bmjopen-2023-082519.

RESULTS

The prevalence of post-COVID-19 conditions in Africa ranged from 2% to as high as 94.7%. Fatigue, dyspnoea and brain fog were among the commonly reported symptoms of post-COVID-19 conditions. Reduced functional status as well as physical and psychosocial disorders were the main health effects reported by the studies reviewed, but no study yet reported the effects of post-COVID-19 conditions on the health systems in Africa.

CONCLUSIONS

There is an evidence of high prevalence of post-COVID-19 conditions in the African setting. However, there is limited evidence of the health effects of the post-COVID-19 conditions on patients and health systems in Africa.

ETHICS AND DISSEMINATION

This scoping review involved analysis of secondary data; therefore, no ethical approval was needed. Dissemination of the result is being done through international journals and may also be presented at available research conferences.

NRICM101 in combatting COVID-19 induced brain fog: Neuroprotective effects and neurovascular integrity preservation in hACE2 mice

Amidst growing concerns over COVID-19 aftereffects like fatigue and cognitive issues, NRICM101, a traditional Chinese medicine, has shown promise. Used by over 2 million people globally, it notably reduces hospitalizations and intubations in COVID-19 patients. To explore whether NRICM101 could combat COVID-19 brain fog, we tested NRICM101 on hACE2 transgenic mice administered the S1 protein of SARS-CoV-2, aiming to mitigate S1-induced cognitive issues by measuring animal behaviors, immunohistochemistry (IHC) staining, and next-generation sequencing (NGS) analysis. The study revealed that S1 protein-administered mice displayed marked signs of brain fog, characterized by reduced learning, memory, and nesting abilities. However, NRICM101 treatment in these animals ameliorated all these cognitive functions. S1 protein administration in mice induced notable inflammation, leading to the death of neurons (NeuN+) and neural stem cells (DCX+) in hACE2 transgenic mice. This was accompanied by heightened microglia activation (IBA1+/CD68+), increased cytokine production (IL1β, IL6), induction of neutrophil extracellular traps (NET), inflammation (NLRP3, CD11b), and platelet (CD31, vWF) and complement (C3) activation, ultimately damaging neurovasculature and disrupting the blood-brain barrier (B.B.B.). Administration of NRICM101 effectively alleviated all these pathological changes. In conclusion, NRICM101 has the potential to prevent COVID-19-associated brain fog by bolstering neurovascular integrity and protecting neurons and neural stem cells. This is achieved by the inhibition of S1 protein-induced complement activation, which in turn leads to the prevention of damage to the neurovasculature and the subsequent death of neurons.

Post-COVID-19 Mental Health Distress in 13 Million Youth: A Retrospective Cohort Study of Electronic Health Records

OBJECTIVE

To investigate the impact of the SARS-CoV-2 infection on the rates of mental disorders in youth.

METHOD

The study involved 7,519,465 children and 5,338,496 adolescents from the TriNetX Research Network, all without prior mental disorder histories. Among them, 290,145 children and 223,667 adolescents had SARS-CoV-2-positive tests or confirmed COVID-19 diagnoses. Kaplan-Meier survival analysis was used to evaluate the probability of developing new mental disorders (any codes in International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) F01-F99 category and suicidal behaviors) within 2 years post infection, compared to the propensity score-matched youth who were never infected.

RESULTS

Within 2 years post SARS-CoV-2 infection, children had a probability of 0.15 in acquiring new psychiatric diagnoses, compared to 0.026 for matched non-infected children; adolescents had a 0.19 probability against 0.05 for their non-infected counterparts. The hazard ratio (HR) was 6.0 (95% CI = 5.8-6.3) for children and 4.2 for adolescents (95% CI = 4.1-4.4), with children vs adolescents HR of 1.4 (95% CI = 1.36-1.51). Elevated HRs were observed for almost all subcategories of mental disorders and suicidal behaviors, with variations based on sex, severity of SARS-CoV-2 infection, and viral variants. COVID-19 was similar to other respiratory infections and was associated with a similarly increased rate of mental disorders in adolescents, but had a significantly higher effect on children (HR = 1.57, 95% CI =1.53-1.61).

CONCLUSION

This study revealed significant mental health distress following SARS-CoV-2 infection in youth, which was more pronounced in children than in adolescents. These findings underscore the urgent need to support at-risk youth, particularly those who contracted SARS-CoV-2 at younger ages and had more severe infections.

PLAIN LANGUAGE SUMMARY

The authors of this study conducted analyses using electronic medical records from the TriNetX Research Network to investigate the impact of SARS-CoV-2 infection on the rates of mental health disorders in youth. Within 2 years after SARS-CoV-2 infection, children and adolescents were 6.0 and 4.2 times more likely to acquire a new psychiatric diagnosis, respectively. While the risk of being diagnosed with a mental health disorder following SARS-CoV-2 infection in adolescents was comparable to other respiratory infections, it had a more pronounced effect on children.

Neurological, psychological, psychosocial complications of long-COVID and their management

Since it first appeared, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has had a significant and lasting negative impact on the health and economies of millions of individuals all over the globe. At the level of individual health too, many patients are not recovering fully and experiencing a long-term condition now commonly termed 'long-COVID'. Long-COVID is a collection of symptoms which must last more than 12 weeks following initial COVID infection, and which cannot be adequately explained by alternate diagnoses. The neurological and psychosocial impact of long-COVID is itself now a global health crisis and therefore preventing, diagnosing, and managing these patients is of paramount importance. This review focuses primarily on: neurological functioning deficits; mental health impacts; long-term mood problems; and associated psychosocial issues, among patients suffering from long-COVID with an eye towards the neurological basis of these symptoms. A concise account of the clinical relevance of the neurological and psychosocial impacts of long-COVID, the effects on long-term morbidity, and varied approaches in managing patients with significant chronic neurological symptoms and conditions was extracted from the literature, analysed and reported. A comprehensive account of plausible pathophysiological mechanisms involved in the development of long-COVID, its management, and future research needs have been discussed.

Proteomic and metabolomic profiling of plasma uncovers immune responses in patients with Long COVID-19

Long COVID is an often-debilitating condition with severe, multisystem symptoms that can persist for weeks or months and increase the risk of various diseases. Currently, there is a lack of diagnostic tools for Long COVID in clinical practice. Therefore, this study utilizes plasma proteomics and metabolomics technologies to understand the molecular profile and pathophysiological mechanisms of Long COVID, providing clinical evidence for the development of potential biomarkers. This study included three age- and gender-matched cohorts: healthy controls (n = 18), COVID-19 recovered patients (n = 17), and Long COVID patients (n = 15). The proteomics results revealed significant differences in proteins between Long COVID-19 patients and COVID-19 recovered patients, with dysregulation mainly focused on pathways such as coagulation, platelets, complement cascade reactions, GPCR cell signal transduction, and substance transport, which can participate in regulating immune responses, inflammation, and tissue vascular repair. Metabolomics results showed that Long COVID patients and COVID-19 recovered patients have similar metabolic disorders, mainly involving dysregulation in lipid metabolites and fatty acid metabolism, such as glycerophospholipids, sphingolipid metabolism, and arachidonic acid metabolism processes. In summary, our study results indicate significant protein dysregulation and metabolic abnormalities in the plasma of Long COVID patients, leading to coagulation dysfunction, impaired energy metabolism, and chronic immune dysregulation, which are more pronounced than in COVID-19 recovered patients.

Machine-Learning Mental-Fatigue-Measuring μm-Thick Elastic Epidermal Electronics (MMMEEE)

Electrophysiological (EP) signals are key biomarkers for monitoring mental fatigue (MF) and general health, but state-of-the-art wearable EP-based MF monitoring systems are bulky and require user-specific, labeled data. Ultrathin epidermal electrodes with high performance are ideal for constructing imperceptive EP sensing systems; however, the lack of a simple and scalable fabrication delays their application in MF recognition. Here, we report a facile, scalable printing-welding-transferring strategy (PWT) for printing μm-thickness micropatterned silver nanowires (AgNWs)/sticky polydimethylsiloxane, welding the AgNWs via plasmonic effect, and transferring the electrode to skin as tattoos. The PWT provides electrodes with conformability, comfort, and stability for EP sensing. Leveraging the facile and scalable PWT, we develop plug-and-play wireless multimodal epidermal electronics integrated with an unsupervised transfer learning (UTL) scheme for MF recognition across various users. The UTL adaptively minimizes the intersubject difference and achieves high accuracy, without demand of expensive computation and labels from target users.

Persistence of Long COVID Symptoms Two Years After SARS-CoV-2 Infection: A Prospective Longitudinal Cohort Study

BACKGROUND/OBJECTIVES

Millions of individuals worldwide continue to experience symptoms following SARS-CoV-2 infection. This study aimed to assess the prevalence and phenotype of multi-system symptoms attributed to Long COVID-including fatigue, pain, cognitive-emotional disturbances, headache, cardiopulmonary issues, and alterations in taste and smell-that have persisted for at least two years after acute infection, which we define as "persistent Long COVID". Additionally, the study aimed to identify clinical features and blood biomarkers associated with persistent Long COVID symptoms.

METHODS

We sent a detailed long COVID symptoms questionnaire to an existing cohort of 1258 vaccinated adults (age 18-79 years) who had mild infection (e.g., non-hospitalized) SARS-CoV-2 Delta variant 2 years earlier. These individuals had comprehensive datasets, including blood samples, available for further analysis. We estimated prevalence of persistent long COVID two years post-infection using weighted adjustment (Horvitz-Thompson estimator) to overcome reporting bias. Multivariable logistic regression models were used to determine association of clinical features and blood biomarkers (pre-infection SARS-CoV-2 RBD-IgG, SARS-CoV-2 neutralizing antibodies, and pre-infection and post-infection neurofilament light) with prevalence of persistent long COVID.

RESULTS

N = 323 participants responded to the survey, of whom N = 74 (23%) reported at least one long COVID symptom that had persisted for two years after the acute infection. Weighted prevalence of persistent long COVID symptoms was 21.5% (95% CI = 16.7-26.3%). Female gender, smoking, and severity of acute COVID-19 infection were significantly associated with persistent Long COVID. The blood biomarkers assessed were not significantly associated with persistent Long COVID.

CONCLUSIONS

Among vaccinated adults two years after mild infection with Delta variant SARS-CoV-2, persistent symptoms attributed to Long COVID are extremely common, certain subgroups are at higher risk, and further research into biological mechanisms and potential treatment targets is needed.

Depression, Anxiety, and Neuropsychiatric Symptom Burden in a Longitudinal Cohort with Persistent Psychophysical Post-COVID Olfactory Dysfunction

BACKGROUND/OBJECTIVES

Olfactory dysfunction (OD) is associated with a variety of neurologic deficits and impacts socialization decisions, mood, and overall quality of life. As a common symptom comprising the long COVID condition, persistent COVID-19-associated olfactory dysfunction (C19OD) may further impact the presentations of neuropsychiatric sequelae. Our study aims to characterize the longitudinal burden of depression, anxiety, and neuropsychiatric symptoms in a population with C19OD.

METHODS

Individuals with perceived C19OD completed a psychophysical screening evaluation of their sense of smell using the comprehensive Sniffin' Sticks olfactory assessment. Only those with validated psychophysical OD were included in this prospective longitudinal study for baseline and one-year follow-up. Participants also completed PHQ-9, Beck Anxiety Inventory (BAI), and neuropsychiatric symptom questionnaires at each time point. Anxiety, depression, and neuropsychiatric symptom prevalence was calculated and compared between time points with Pearson's chi-squared, Fisher's exact, and Wilcoxon rank sum tests.

RESULTS

Each neuropsychiatric symptom evaluated in this study was reported by 13-49% of longitudinal cohort participants at both baseline and follow-up, except for seizure (0% at baseline and follow-up) and word-finding difficulty (61-68% at baseline and follow-up). Word-finding and focus difficulties were the most commonly reported symptoms. In total, 41% of participants reported some level of depression at baseline and 38% of participants reported depression at one-year follow-up, while 29% and 27% of participants reported some level of anxiety at respective time points.

CONCLUSIONS

Individuals with C19OD are at risk for developing persistent neuropsychiatric conditions. These neurologic and psychiatric sequelae are persistent with repeated longitudinal assessment, even at nearly 2.5 years following initial COVID-19 diagnosis.

Identification of RdRp-NiRAN/JAK1 Dual-Target Drugs for COVID-19 Treatment

Inhibition of virus replication and inflammatory response is important for the treatment of severe COVID-19 patients. RNA-dependent RNA polymerase (RdRp) is indispensable for SARS-CoV-2 replication, and Janus kinase (JAK) 1 inhibitors exert immunosuppressive effects. RdRp/JAK1 dual-target drugs are expected to ameliorate the severity of the COVID-19 disease. The N-terminal nidovirus RdRp-associated nucleotidyltransferase (NiRAN) domain of RdRp is a pseudokinase, and it has structural similarities with JAK1. Herein, we evaluated the inhibitory effects of triphosphate forms of 31 nucleoside drugs in the DrugBank database on the NiRAN domain and JAK1 through a combination of theoretical and experimental methods. By analyzing the three properties of 31 nucleoside drugs (total hydrophobic surface area, number of hydrophobic atoms, and molecular weight), these drugs met the application rule of our developed molecular docking with conformer-dependent charges (MDCC). Based on the MDCC method combined with molecular dynamics simulations, Azvudine and Citicoline among these 31 drugs showed stronger predicted binding affinities with the NiRAN domain as well as JAK1 compared to the reference drug Remdesivir. Further experimental verification, including a thermal shift assay and homogeneous time-resolved fluorescence assay, demonstrated that Azvudine was an RdRp-NiRAN/JAK1 dual-target drug. This work provided a previously unexplored mechanism of Azvudine for COVID-19 treatment and proposed a design concept for RdRp-NiRAN/JAK1 dual-target nucleoside drugs.

A clinical approach to the investigation and management of long COVID associated neuropathic pain

COVID-19 has been associated with a wide range of ongoing symptoms following recovery from the acute SARS-CoV-2 infection. Around one in three people with COVID-19 develop neurological symptoms with many reporting neuropathic pain and associated symptoms, including paraesthesia, numbness, and dysesthesia. Whilst the pathophysiology of long COVID-19-associated neuropathic pain remains unclear, it is likely to be multifactorial. Early identification, exclusion of common alternative causes, and a biopsychosocial approach to the management of the symptoms can help in relieving the burden of disease and improving the quality of life for patients.

Beetroot juice intake positively influenced gut microbiota and inflammation but failed to improve functional outcomes in adults with long COVID: A pilot randomized controlled trial

BACKGROUND & AIMS

Long-term effects of coronavirus disease 2019 (long COVID) develop in a substantial number of people following an acute COVID-19 episode. Red beetroot juice may have positive effects on multiple pathways involved in long COVID. The aim of this pilot study was to explore the impact of beetroot juice supplementation on physical function, gut microbiota, and systemic inflammation in adults with long COVID.

METHODS

A single-center, double-blind, placebo-controlled randomized trial was conducted to test the effects of 14 days of beetroot juice supplementation, rich in nitrates and betalains, on functional and biological outcomes in adults aged between 20 and 60 years with long COVID. Participants were randomized 1:1 to receive either daily oral supplementation with 200 mL beetroot juice (∼600 mg nitrate) or placebo (∼60 mg nitrate) for 14 days. The primary endpoint was the change from baseline to day 14 in a fatigue resistance test. Secondary outcomes included the distance walked on the 6-min walk test, handgrip strength, and flow-mediated dilation. Secondary endpoints also included changes from baseline in circulating inflammatory mediators and metagenomic and fecal water metabolomic profiles. Partial least squares discriminant analysis (PLS-DA) models were built to evaluate the differences in biological variables associated with the interventions.

RESULTS

Thirty-one participants were randomized in the study. Twenty-five of them (median (interquartile range) age 40 (10), 14 [56 %] women), received either beetroot juice (15) or placebo (10) and completed the study. At 14 days, fatigue resistance significantly improved from baseline (mean difference [standard error]: +21.8 [3.7] s; p < 0.001) with no significant differences between intervention groups. A significant increase from baseline in the distance walked on the 6-min walk test was observed (mean difference [standard error]: +30.0 [9.4] m; p = 0.03), which was not different between groups. Flow-mediated dilation did not differ between participants who received beetroot juice and those on placebo. PLS-DA models allowed correct classification of participants with 92.2 ± 4.4 % accuracy. Those who ingested red beetroot juice had a greater abundance of bacteria with well-known beneficial effects, including Akkermansia, Oscillospira, Prevotella, Roseburia, Ruminococcaceae, and Turicibacter, compared with placebo. Participants allocated to beetroot juice supplementation were also characterized by significantly higher levels of fecal nicotinate, trimethylamine, and markers of beetroot juice intake (e.g., 5,6-dihydroxyindole). Finally, higher levels of interferon gamma and macrophage inflammatory protein-1β were found in participants who consumed beetroot juice.

CONCLUSION

Beetroot juice supplementation for two weeks did not to induce significant improvements in functional outcomes in adults with long COVID compared with placebo. Beneficial effects were observed in both gut microbiota composition (i.e., increase in probiotic species) and inflammatory mediators.

TRIAL REGISTRATION

Trial was registered under ClinicalTrials.gov. Identifier no. NCT06535165.

Anxiety and depression symptoms among patients with long COVID: a retrospective cohort study

Patients suffering from post-acute sequelae of COVID-19 (PASC) have a higher prevalence of anxiety and depression than the general population. The long-term trajectory of these sequelae is still unfolding. To assess the burden of anxiety and depression among patients presenting to the University of Iowa Hospitals and Clinics (UIHC) post-COVID-19 clinic, we analyzed how patient factors influenced Generalized Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire-9 (PHQ-9) scores. In this retrospective cohort study, the GAD-7 and PHQ-9 questionnaire scores of patients presenting to the UIHC post-COVID clinic between March 2021-February 2022 (N = 455) were compared to the scores of a sample of patients presenting to the general internal medicine (GIM) clinic during the same period (N = 94). Our analysis showed that patients with an absent history of depression on their electronic medical record (EMR) problem list scored significantly higher on the GAD-7 (mean difference -1.62, 95% CI -3.12 to -0.12, p = 0.034) and PHQ-9 (mean difference -4.45, 95% CI -5.53 to -3.37, p < 0.001) questionnaires compared to their similar counterparts in the GIM clinic. On the other hand, patients with an absent history of anxiety on their EMR problem list scored significantly higher on the GAD-7 (mean difference -2.90, 95% CI -4.0 to -1.80, p < 0.001) but not on the PHQ-9 questionnaire (p = 0.196). Overall, patients with PASC may have experienced a heavier burden of newly manifest anxiety and depression symptoms compared to patients seen in the GIM clinic. This suggests that the mental health impacts of PASC may be more pronounced in patients with no prior history of anxiety or depression.

Neurological Sequelae of Post-COVID-19 Fatigue: A Narrative Review of Dipeptidyl Peptidase IV-Mediated Cerebrovascular Complications

Coronavirus disease 2019 (COVID-19) has been a global pandemic affecting millions of people's lives, which has led to 'post-COVID-19 fatigue'. Alarmingly, severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) not only infects the lungs but also influences the heart and brain. Endothelial cell dysfunction and hypercoagulation, which we know occur with this infection, lead to thrombo-inflammation that can manifest as many myriad cardio-cerebrovascular disorders, such as brain fog, fatigue, cognitive dysfunction, etc. Additionally, SARS-CoV-2 has been associated with oxidative stress, protein aggregation, cytokine storm, and mitochondrial dysfunction in neurodegenerative diseases. Accordingly, the identification of molecular targets involved in these actions could provide strategies for preventing and treating this disease. In particular, the very common enzyme dipeptidyl peptidase IV (DPPIV) has recently been identified as a candidate co-receptor for the cell entry of the SARS-CoV-2 virus with its involvement in infection. In addition, DPPIV has been reported as a co-receptor for some viruses such as Middle East respiratory syndrome-coronavirus (MERS-CoV). It mediates immunologic reactions and diseases such as type 2 diabetes mellitus, obesity, and hypertension, which have been considered the prime risk factors for stroke among other types of cardio-cerebrovascular diseases. Unlike angiotensin-converting enzyme 2 (ACE2), DPPIV has been implicated in aggravating the course of infection due to its disruptive effect on inflammatory signaling networks and the neuro-glia-vascular unit. Regarding the neurological, physiological, and molecular grounds governing post-COVID-19 fatigue, this review focuses on DPPIV as one of such reasons that progressively establishes cerebrovascular grievances following SARS-CoV infection.

SARS-CoV-2 and HSV-1 Induce Amyloid Aggregation in Human CSF Resulting in Drastic Soluble Protein Depletion

The corona virus (SARS-CoV-2) pandemic and the resulting long-term neurological complications in patients, known as long COVID, have renewed interest in the correlation between viral infections and neurodegenerative brain disorders. While many viruses can reach the central nervous system (CNS) causing acute or chronic infections (such as herpes simplex virus 1, HSV-1), the lack of a clear mechanistic link between viruses and protein aggregation into amyloids, a characteristic of several neurodegenerative diseases, has rendered such a connection elusive. Recently, we showed that viruses can induce aggregation of purified amyloidogenic proteins via the direct physicochemical mechanism of heterogeneous nucleation (HEN). In the current study, we show that the incubation of HSV-1 and SARS-CoV-2 with human cerebrospinal fluid (CSF) leads to the amyloid aggregation of several proteins known to be involved in neurodegenerative diseases, such as APLP1 (amyloid β precursor like protein 1), ApoE, clusterin, α2-macroglobulin, PGK-1 (phosphoglycerate kinase 1), ceruloplasmin, nucleolin, 14-3-3, transthyretin, and vitronectin. Importantly, UV-inactivation of SARS-CoV-2 does not affect its ability to induce amyloid aggregation, as amyloid formation is dependent on viral surface catalysis via HEN and not its ability to replicate. Additionally, viral amyloid induction led to a dramatic drop in the soluble protein concentration in the CSF. Our results show that viruses can physically induce amyloid aggregation of proteins in human CSF and result in soluble protein depletion, thus providing a potential mechanism that may account for the association between persistent and latent/reactivating brain infections and neurodegenerative diseases.

Hospitalization for SARS-CoV-2 and the risk of self-harm readmission: a French nationwide retrospective cohort study

AIMS

The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on the risk of self-harming behaviours warrants further investigation. Here, we hypothesized that people with a history of hospitalization for self-harm may be particularly at risk of readmission in case of SARS-CoV-2 hospitalization.

METHODS

We conducted a retrospective analysis based on the French national hospitalization database. We identified all patients hospitalized for deliberate self-harm (10th edition of the International Classification of Diseases codes X60-X84) between March 2020 and March 2021. To study the effect of SARS-CoV-2 hospitalization on the risk of readmission for self-harm at 1-year of the inclusion, we performed a multivariable Fine and Gray model considering hospital death as a competing event.

RESULTS

A total of 61,782 individuals were hospitalized for self-harm. During the 1-year follow-up, 9,403 (15.22%) were readmitted for self-harm. Between inclusion and self-harm readmission or the end of follow-up, 1,214 (1.96% of the study cohort) were hospitalized with SARS-CoV-2 (mean age 60 years, 52.9% women) while 60,568 were not (mean age 45 years, 57% women). Multivariate models revealed that the factors independently associated with self-harm readmission were: hospitalization with SARS-CoV-2 (adjusted hazard ratio (aHR) = 3.04 [2.73-3.37]), psychiatric disorders (aHR = 1.61 [1.53-1.69]), self-harm history (aHR = 2.00 [1.88-2.04]), intensive care and age above 80.

CONCLUSIONS

In hospitalized people with a personal history of self-harm, infection with SARS-CoV-2 increased the risk of readmission of self-harm, with an effect that seemed to add to the effect of a history of mental disorders, with an equally significant magnitude. Infection may be a significantly stressful condition that precipitates self-harming acts in vulnerable individuals. Clinicians should pay particular attention to the emergence of suicidal ideation in these patients in the aftermath of SARS-CoV-2 infection.

Cytoskeletal β-tubulin and cysteine cathepsin L deregulation by SARS-CoV-2 spike protein interaction with the neuronal model cell line SH-SY5Y

SARS-CoV-2 mainly infects the respiratory tract but can also target other organs, including the central nervous system. While it was recently shown that cells of the blood-brain-barrier are permissive to SARS-CoV-2 infection in vitro, it remains debated whether neurons can be infected. In this study, we demonstrate that vesicular stomatitis virus particles pseudotyped with the spike protein of SARS-CoV-2 variants WT, Alpha, Delta and Omicron enter the neuronal model cell line SH-SY5Y. Cell biological analyses of the pseudo-virus treated cultures showed marked alterations in microtubules of SH-SY5Y cells. Because the changes in β-tubulin occurred in most cells, but only few were infected, we further asked whether interaction of the cells with spike protein might be sufficient to cause molecular and structural changes. For this, SH-SY5Y cells were incubated with trimeric spike proteins for time intervals of up to 24 h. CellProfiler™-based image analyses revealed changes in the intensities of microtubule staining in spike protein-incubated cells. Furthermore, expression of the spike protein-processing protease cathepsin L was found to be up-regulated by wild type, Alpha and Delta spike protein pseudotypes and cathepsin L was found to be secreted from spike protein-treated cells. We conclude that the mere interaction of the SARS-CoV-2 with neuronal cells can affect cellular architecture and proteolytic capacities. The molecular mechanisms underlying SARS-CoV-2 spike protein induced cytoskeletal changes in neuronal cells remain elusive and require future studies.

Brain-wide alterations revealed by spatial transcriptomics and proteomics in COVID-19 infection

Understanding the pathophysiology of neurological symptoms observed after severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection is essential to optimizing outcomes and therapeutics. To date, small sample sizes and narrow molecular profiling have limited the generalizability of findings. In this study, we profiled multiple cortical and subcortical regions in postmortem brains of patients with coronavirus disease 2019 (COVID-19) and controls with matched pulmonary pathology (total n = 42) using spatial transcriptomics, bulk gene expression and proteomics. We observed a multi-regional antiviral response without direct active SARS-CoV2 infection. We identified dysregulation of mitochondrial and synaptic pathways in deep-layer excitatory neurons and upregulation of neuroinflammation in glia, consistent across both mRNA and protein. Remarkably, these alterations overlapped substantially with changes in age-related neurodegenerative diseases, including Parkinson's disease and Alzheimer's disease. Our work, combining multiple experimental and analytical methods, demonstrates the brain-wide impact of severe acute/subacute COVID-19, involving both cortical and subcortical regions, shedding light on potential therapeutic targets within pathways typically associated with pathological aging and neurodegeneration.

Emerging small-molecule antiviral agents in long COVID prevention

Long COVID, or Post-Acute Sequelae of COVID-19 (PASC), was characterized by persistent symptoms such as fatigue, shortness of breath, and cognitive impairments. These symptoms, emerging one to 2 months post-infection and persisting for several months, cannot be attributed to other diagnoses. The pathophysiology of long COVID remained elusive; however, emerging studies suggested multiple potential mechanisms, including the reactivation of Epstein-Barr virus, persistent SARS-CoV-2 reservoirs, neuroinflammation, and vascular damage, which may contribute to its development. Long COVID affected multiple organ systems, including respiratory, circulatory, and nervous systems, leading to a range of functional impairments. Additionally, it showed a profound impact on mental health, manifesting as anxiety and depression, which significantly degraded the quality of life. The absence of definitive treatments underscored the importance of prevention. Recent evidence indicated that early antiviral intervention-particularly with small-molecule drugs such as Metformin, Ensitrelvir, Molnupiravir, and Nirmatrelvir-may effectively reduce the incidence of long COVID. This underscored the promising role of small-molecule compounds in mitigating long-term COVID-19 consequences, offering a novel preventive strategy against long COVID and its extensive impacts on patients.

Short-term intermittent hypoxia exposure for dyspnea and fatigue in post-acute sequelae of COVID-19: A randomized controlled study

BACKGROUND

Post-acute sequelae of COVID-19 (PASC) is incurring a huge health and economic burden worldwide. There is currently no effective treatment or recommended drug for PASC.

METHODS

This prospective randomized controlled study was conducted in a hospital in China. The effect of intermittent hypoxia exposure (IHE; 5-min hypoxia alternating with 5-min normal air, repeated five times) on dyspnea and fatigue was investigated in patients meeting the NICE definition of PASC. Patients were computationally randomized to receive normoxia exposure (NE) and routine therapy or IHE and routine therapy. Six-minute walk distance (6MWD) and spirometry were tested before and after the interventions; the Borg Dyspnea Scale (Borg) and the modified Medical Research Council Dyspnea Scale (mMRC) were used to assess dyspnea; and the Fatigue Assessment Scale (FAS) and the Chalder Fatigue Scale-11 (CFQ-11) were used to assess fatigue. The study was registered in the Chinese Clinical Trial Registry (ChiCTR2300070565).

FINDINGS

Ninety-five participants (33 males and 62 females) were recruited between March 1, 2023 and December 30, 2023. Forty-seven patients in the IHE group received 10.0 (9.0, 15.0) days of IHE, and 48 patients in NE group received 10.0 (8.0, 12.0) days of NE. 6MWD, forced vital capacity (FVC), FVC %pred, forced expiratory volume in 1 s (FEV1), FEV1 %pred, tidal volume (VT), and dyspnea and fatigue scales markedly improved after IHE (p < 0.05), and improvements were greater than in the NE group (all p < 0.05). Furthermore, participants in IHE group had better subjective improvements in dyspnea and fatigue than those in the NE group (p < 0.05). Compared with <10 days of IHE, ≥10 days of IHE had a greater impact on 6MWD, FVC, FEV1, FEV1 %pred, VT, FAS, and CFQ-11. No severe adverse events were reported.

INTERPRETATION

IHE improved spirometry and 6MWD and relieved dyspnea and fatigue in PASC patients. Larger prospective studies are now needed to verify these findings.

Neuro-molecular perspectives on long COVID-19 impacted cerebrovascular diseases - a role for dipeptidyl peptidase IV

The coronavirus disease 2019 (COVID-19) has caused immense devastation globally with many outcomes that are now extending to its long-term sequel called long COVID. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects not only lungs, but also the brain and heart in association with endothelial cell dysfunction, coagulation abnormalities, and thrombosis leading to cardio-cerebrovascular health issues. Fatigue, cognitive decline, and brain fog are common neurological symptoms in persisting long COVID. Neurodegenerative processes and SARS-CoV-2 infection manifest overlapping molecular mechanisms, such as cytokine dysregulation, inflammation, protein aggregation, mitochondrial dysfunction, and oxidative stress. Identifying the key molecules in these processes is of importance for prevention and treatment of this disease. In particular, Dipeptidyl peptidase IV (DPPIV), a multifunctional peptidase has recently drawn attention as a potential co-receptor for SARS-CoV-2 infection and cellular entry. DPPIV is a known co-receptor for some other COVID viruses including MERS-Co-V. DPPIV regulates the immune responses, obesity, glucose metabolism, diabetes, and hypertension that are associated with cerebrovascular manifestations including stroke. DPPIV likely worsens persisting COVID-19 by disrupting inflammatory signaling pathways and the neurovascular system. This review highlights the neurological, cellular and molecular processes concerning long COVID, and DPPIV as a potential key factor contributing to cerebrovascular dysfunctions following SARS-CoV-2 infection.

An integrated bioinformatics approach reveals the potential role of microRNA-30b-5p and let-7a-5p during SARS CoV-2 spike-1 mediated neuroinflammation

SARS-CoV-2 induced neuroinflammation contributing to neurological sequelae is one of the critical outcomes of long-COVID, however underlying regulatory mechanisms involved therein are poorly understood. We deciphered the profile of dysregulated microRNAs, their targets, associated pathways, protein-protein interactions (PPI), transcription factor-hub genes interaction networks, hub genes-microRNA co-regulatory networks in SARS-CoV-2 Spike-1 (S1) stimulated microglial cells along with candidate drug prediction using RNA-sequencing and multiple bioinformatics approaches. We identified 11 dysregulated microRNAs in the S1-stimulated microglial cells (p < 0.05). KEGG analysis revealed involvement of important neuroinflammatory pathways such as MAPK signalling, PI3K-AKT signalling, Ras signalling and axon guidance. PPI analysis further identified 11 hub genes involved in these pathways. Real time PCR validation confirmed a significant upregulation of microRNA-30b-5p and let-7a-5p; proinflammatory cytokines- IL-6, TNF-α, IL-1β, GM-CSF; and inflammatory genes- PIK3CA and AKT in the S1-stimulated microglial cells, while PTEN and SHIP1 expression was decreased as compared to the non-stimulated cells. Drug prediction analysis further indicated resveratrol, diclofenac and rapamycin as the potential drugs based on their degree of interaction with hub genes. Thus, targeting of these microRNAs and/or their intermediate signalling molecules would be a prospective immunotherapeutic approach in alleviating SARS-CoV-2-S1 mediated neuroinflammation; and needs further investigations.

Understanding autoimmune response after SARS-CoV-2 infection and the pathogenesis/mechanisms of long COVID

COVID-19 posed a major challenge to the healthcare system and resources worldwide. The popularization of vaccines and the adoption of numerous prevention and control measures enabled the gradual end of the COVID-19 pandemic. However, successive occurrence of autoimmune diseases in patients with COVID-19 cannot be overlooked. Long COVID has been the major focus of research due to the long duration of different symptoms and the variety of systems involved. Autoimmunity may play a crucial role in the pathogenesis of long COVID. Here, we reviewed several autoimmune disorders occurring after COVID-19 infection and the pathogenesis of long COVID.

The Intersections of COVID-19, HIV, and Race/Ethnicity: Machine Learning Methods to Identify and Model Risk Factors for Severe COVID-19 in a Large U.S. National Dataset

We investigate risk factors for severe COVID-19 in persons living with HIV (PWH), including among racialized PWH, using the U.S. population-sampled National COVID Cohort Collaborative (N3C) data released from January 1, 2020 to October 10, 2022. We defined severe COVID-19 as hospitalized with invasive mechanical ventilation, extracorporeal membrane oxygenation, discharge to hospice or death. We used machine learning methods to identify highly ranked, uncorrelated factors predicting severe COVID-19, and used multivariable logistic regression models to assess the associations of these variables with severe COVID-19 in several models, including race-stratified models. There were 3 241 627 individuals with incident COVID-19 cases and 81 549 (2.5%) with severe COVID-19, of which 17 445 incident COVID-19 and 1 020 (5.8%) severe cases were among PWH. The top highly ranked factors of severe COVID-19 were age, congestive heart failure (CHF), dementia, renal disease, sodium concentration, smoking status, and sex. Among PWH, age and sodium concentration were important predictors of COVID-19 severity, and the effect of sodium concentration was more pronounced in Hispanics (aOR 4.11 compared to aOR range: 1.47-1.88 for Black, White, and Other non-Hispanics). Dementia, CHF, and renal disease was associated with higher odds of severe COVID-19 among Black, Hispanic, and Other non-Hispanics PWH, respectively. Our findings suggest that the impact of factors, especially clinical comorbidities, predictive of severe COVID-19 among PWH varies by racialized groups, highlighting a need to account for race and comorbidity burden when assessing the risk of PWH developing severe COVID-19.

Changes in strength performance of highly trained athletes after COVID-19

INTRODUCTION

This study aimed to explore the impact of COVID-19 on strength performance in highly trained athletes.

METHOD

A force plate was employed to measure squat jump height (SJH), counter-movement jump height (CMJH), and drop jump reactive strength index (DJRSI) in 27 highly trained athletes before infection, and at one week, two weeks, and four weeks post-recovery. Additionally, an Isometric Mid-thigh Pull (IMTP) test was conducted to record maximum isometric strength (MIS) and the rate of force development of the initial phase (RFD 0-50; RFD 0-100). Repeated measures analysis of variance was utilized to compare variations in these indicators across different time points.

RESULTS

One week post-recovery, SJH (-7.71%, P = 0.005), CMJH (-9.08%, P < 0.001), DJRSI (-28.88%, P < 0.001), MIS (-18.95%, P < 0.001), RFD 0-50 (-64.98%, P < 0.001), and RFD 0-100 (-53.65%, P < 0.001) were significantly lower than pre-infection levels. Four weeks post-recovery, SJH (-2.08%, P = 0.236), CMJH (-3.28%, P = 0.277), and MIS (-3.32%, P = 0.174) did not differ significantly from pre-infection levels. However, DJRSI (-11.24%, P = 0.013), RFD 0-50 (-31.37%, P = 0.002), and RFD 0-100 (-18.99%, P = 0.001) remained significantly lower than pre-infection levels.

CONCLUSION

After COVID-19, highly trained athletes exhibited a significant reduction in maximum strength, explosive strength, reactive strength, and initial phase force generation capability. By four weeks post-recovery, their maximum and explosive strength had returned to near pre-infection levels, yet their reactive strength and initial phase force generation capability remained significantly impaired.

Causal effect of COVID-19 on longitudinal volumetric changes in subcortical structures: A mendelian randomization study

A few observational neuroimaging investigations have reported subcortical structural changes in the individuals who recovered from the coronavirus disease-2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but the causal relationships between COVID-19 and longitudinal changes of subcortical structures remain unclear. We performed two-sample Mendelian randomization (MR) analyses to estimate putative causal relationships between three COVID-19 phenotypes (susceptibility, hospitalization, and severity) and longitudinal volumetric changes of seven subcortical structures derived from MRI. Our findings demonstrated that genetic liability to SARS-CoV-2 infection had a great long-term impact on the volumetric reduction of subcortical structures, especially caudate. Our investigation may contribute in part to the understanding of the neural mechanisms underlying COVID-19-related neurological and neuropsychiatric sequelae.