Effects of COVID-19 on the Nervous System

Long Coronavirus Disease and the Brain: Molecular Neuroimaging Insights into Neurologic and Psychiatric Sequelae

The coronavirus disease 2019 (COVID-19) pandemic has led to a variety of health challenges, with "long COVID" emerging as a widespread and debilitating post-acute syndrome among a considerable number of infected patients. This PET review synthesizes current evidence of the neurologic and psychiatric sequelae of COVID. This review also explores the pathophysiological mechanisms of these results, including astrocyte dysfunction and glutamate dysregulation, as well as the multimodal comparison to MR imaging findings. The findings underscore the potential for long-term brain injury. Additionally, the authors discuss the role of advanced imaging multimodal techniques in diagnosing, monitoring, and guiding treatment strategies for long COVID.

Cognitive Impairment and Brain Metabolic Changes in Post-Acute Sequelae of COVID-19: Insights From an [18F]FDG PET/CT Cohort Study

PURPOSE

Neurological symptoms often prominent in post-acute sequelae of COVID-19 (PASC) necessitate deeper understanding. Our objective was to investigate brain metabolism in PASC and examine correlations with neurological symptoms during both the acute and chronic stages.

METHODS

Eighty-seven adults experiencing PASC with neurocognitive symptoms were recruited in the PERSICOR prospective study and examined using brain [18F]FDG PET/CT. Comprehensive clinical variables including neurocognitive symptoms were evaluated. PET images were compared voxel-wise with SPM12 software (P < 0.05, false discovery rate corrected) and volume-of-interest basis (BrainVisa software) with those of 55 healthy controls recruited before COVID-19 pandemic. We also investigated differences in brain metabolism according to the time interval after acute COVID-19. The correlation between brain metabolism and neurocognitive symptoms was assessed.

RESULTS

Frequently reported neurological symptoms included concentration difficulties (79%) and immediate/working memory impairments (66%). Significant hypometabolism was identified in regions previously identified in PASC: left fusiform gyrus (33% of patients), amygdala (23% on left, 28% on right), parahippocampal area (25% left, 24% right), and vermis (22%). The most substantial metabolism decreases were observed in the pons (5.5% decrease in the whole patient group vs controls) and right amygdala (-4.2%). Concentration and memory impairments correlated with decreased metabolism in prefrontal and mesial/inferior temporal areas, respectively (P < 0.01 for both). A shorter interval between PET imaging and the acute phase of COVID-19 correlated with reduced glucose metabolism in the brainstem, thalamus, mesiotemporal lobe, frontobasal cortex, and olfactory bulb (P < 10-3).

CONCLUSION

This study underscores the links between neurological symptoms and cerebral hypometabolism in specific regions in PASC. These findings illuminate the complex neuropathophysiological mechanisms of PASC and pave the way for potential therapeutic interventions.

What Is the Impact of the Novel Coronavirus and the Vaccination on Guillain-Barre Syndrome?

The COVID-19 pandemic, caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has resulted in devastating medical and economic consequences worldwide over the past 3 years. As the pandemic enters a new stage, it is essential to consider the potential impact on rare diseases such as Guillain-Barre syndrome (GBS), which has been intimately associated with COVID-19 since the first COVID-19-related GBS case was reported in January 2020. There are notable differences between COVID-19-related GBS and GBS without COVID-19 in terms of diagnostic types and clinical manifestations. Furthermore, with the widespread administration of COVID-19 vaccines, there have been reports of GBS occurring shortly after vaccination, which requires close attention despite its rarity. This review also explores the vaccines associated with heightened GBS risks, offering insights that may guide vaccination policies and clinical practice. To provide a visual summary of these findings, we have included a graphical abstract.

COVID-19, Anxiety, and Body Mass Index Increase Leptin Levels: a Cross-sectional Multicentric Study

Although many efforts have been made to understand the pathophysiological mechanisms of COVID-19, critical gaps remain to be explored. This study aimed to investigate potential alterations in adipokine levels (specifically adiponectin, leptin, and resistin) among individuals with COVID-19. Within this population, we further assessed the association between these markers with both, body mass index (BMI) and psychiatric symptoms. This cross-sectional study included an age- and sex-matched sample of adults with COVID-19 (cases) and without COVID-19 (controls). We evaluated the severity of psychiatric symptoms, BMI, and adipokines. Individuals with COVID-19 presented greater BMI, stress levels, and leptin levels when compared to controls. Leptin levels were greater in individuals with moderate/severe COVID-19 as compared to individuals with COVID-19 who were asymptomatic or having mild symptoms. Leptin levels were positively correlated with BMI, severity of depressive and anxiety symptoms, and stress levels in the total sample. Leptin levels were also positively correlated with BMI, severity of anxiety symptoms, and stress levels in controls. In cases, there was a positive correlation between adiponectin and the severity of depressive symptoms and stress levels and leptin/resistin with BMI. A linear regression model revealed that BMI, severity of anxiety symptoms, and the diagnosis of COVID-19 are independently associated with increased leptin levels. Thus, leptin levels seem to be impacted by the COVID-19 infection, anxiety, and BMI.

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.

A nomogram to predict long COVID risk based on pre- and post-infection factors: Results from a cross-sectional study in South China

OBJECTIVES

Long COVID has received much attention as a complex multi-system disease due to its serious impact on quality of life. However, there remains inconsistent results in terms of risk factors, and a prediction model for the accurate prediction of long COVID is still lacking.

STUDY DESIGN

Cross-sectional study.

METHODS

In this retrospective study, a community population from the Futian District of Shenzhen, Guangdong Province, China, were included. Data were collected from September to December 2023 using an electronic questionnaire. Logistic regression analyses were used to identify predictors of long COVID. Pre-infection and post-infection prediction models (with/without post-infection characteristics) were developed, and the C-index was used to evaluate accuracy.

RESULTS

In total, 420 patients infected COVID-19 were included. The prevalence of long COVID was 32.9 %. The most common symptoms of long COVID were weakness/fatigue, persistent cough and cognitive dysfunction. Independent predictors of long COVID included in the pre-infection model were age, long-term medication, and psychological problems such as stress and doing things without enthusiasm/interest before COVID-19 infection (C-index: 0.721). Independent predictors included in the post-infection model were age, inability to concentrate before COVID-19 infection, and symptoms of weakness/fatigue, abnormal smell/taste, diarrhoea, eye conjunctivitis and headache/dizziness during the acute-phase (C-index: 0.857).

CONCLUSIONS

Age, psychological problems before COVID-19 infection and acute-phase symptoms were important risk factors of long COVID. Results from the pre-infection model provide guidance for non-infected individuals on how to prevent long COVID. Results from the post-infection model can be used to accurately predict individuals who are at high risk of long COVID and help design treatment plans for patients in the acute phase.

Neurocognitive and psychiatric outcomes associated with postacute COVID-19 infection without severe medical complication: a meta-analysis

BACKGROUND

Cognitive symptoms are often reported by those with a history of COVID-19 infection. No comprehensive meta-analysis of neurocognitive outcomes related to COVID-19 exists despite the influx of studies after the COVID-19 pandemic. This study meta-analysed observational research comparing cross-sectional neurocognitive outcomes in adults with COVID-19 (without severe medical/psychiatric comorbidity) to healthy controls (HCs) or norm-referenced data.

METHODS

Data were extracted from 54 studies published between January 2020 and June 2023. Hedges' g was used to index effect sizes, which were pooled using random-effects modelling. Moderating variables were investigated using meta-regression and subgroup analyses.

RESULTS

Omnibus meta-analysis of 696 effect sizes extracted across 54 studies (COVID-19 n=6676, HC/norm-reference n=12 986; average time since infection=~6 months) yielded a small but significant effect indicating patients with COVID-19 performed slightly worse than HCs on cognitive measures (g=-0.36; 95% CI=-0.45 to -0.28), with high heterogeneity (Q=242.30, p<0.001, τ=0.26). Significant within-domain effects was yielded by cognitive screener (g=-0.55; 95% CI=-0.75 to -0.36), processing speed (g=-0.44; 95% CI=-0.57 to -0.32), global cognition (g=-0.40; 95% CI=-0.71 to -0.09), simple/complex attention (g=-0.38; 95% CI=-0.46 to -0.29), learning/memory (g=-0.34; 95% CI=-0.46 to -0.22), language (g=-0.34; 95% CI=-0.45 to -0.24) and executive function (g=-0.32; 95% CI=-0.43 to -0.21); but not motor (g=-0.40; 95% CI=-0.89 to 0.10), visuospatial/construction (g=-0.09; 95% CI=-0.23 to 0.05) and orientation (g=-0.02; 95% CI=-0.17 to 0.14). COVID-19 samples with elevated depression, anxiety, fatigue and disease severity yielded larger effects.

CONCLUSION

Mild cognitive deficits are associated with COVID-19 infection, especially as detected by cognitive screeners and processing speed tasks. We failed to observe clinically meaningful cognitive impairments (as measured by standard neuropsychological instruments) in people with COVID-19 without severe medical or psychiatric comorbidities.

Inter- and intra-examiner reliability of short-term measurement of heart rate variability on rest in patients hospitalized with COVID-19

Measures reflecting cardiac sympathovagal activity, particularly those associated with heart rate variability (HRV), are widely recognized and utilized in both scientific and clinical contexts. This study aimed to assess the inter- and intra-examiner reliability of short-term HRV parameters in patients hospitalized with coronavirus disease 2019 (COVID-19). A total of 103 patients (both sexes) diagnosed with COVID-19 were included in the study. HRV was analyzed using both linear and nonlinear methods. Reliability was evaluated through intraclass correlation coefficient (ICC2.1), minimum detectable change (MDC), standard error of measurement (SEM), and coefficient of variation (CV). According to Fleiss' criteria, excellent reliability was demonstrated, with ICC values ranging from 0.970 to 0.999 for Examiner 1, and from 0.956 to 0.999, for Examiner 2. In the inter-examiner analysis, the ICCs of HRV parameters ranged from 0.972 to 0.999. SEM values for intra-examiner reliability for Examiner 1 ranged from 0.02 to 5.64, with MDC values from 0.05 to 15.64, and CV (%) from 0.28 to 8.04. For Examiner 2, SEM values ranged from 0.02 to 8.18, MDC values from 0.05 to 22.68, and CV (%) from 0.24 to 8.14. For inter-examiner reliability, SEM values ranged from 0.02 to 6.17, MDC from 0.06 to 17.11, and CV (%) from 0.34 to 9.81. Across all analyses, CVs for HRV parameters remained below 10%. Considering different time points and different examiners, short-term resting HRV measurements in patients hospitalized with COVID-19, as evaluated using a portable heart rate device, exhibit high reliability.

The risk of cognitive decline and dementia in older adults diagnosed with COVID-19: A systematic review and meta-analysis

BACKGROUND

Cognitive impairment can be caused by infections with various pathogens, including SARS-CoV-2. Research has yet to determine the true incidence and course of cognitive impairment in older adults following COVID-19. Furthermore, research has theorised that COVID-19 is associated with dementia progression and diagnosis but this association has yet to be fully described.

METHODS

A systematic review was registered in Prospero and conducted on the databases PubMed, Embase, Ovid, CENTRAL and Cochrane Library. Studies reporting cognitive impairment and dementia outcomes in post-acute and post-COVID-19 patients aged ≥65 years, and which included control data, were included in this review.

RESULTS

15,124 articles were identified by the search strategy. After eliminating duplicate titles and completing title, abstracts and full-text review, 18 studies were included comprising of 412,957 patients with COVID-19 (46.63 % male) and 411,929 patients without COVID-19 (46.59 % male). The overall mean Montreal Cognitive Assessment (MoCA) score in COVID-19 patients was 23.34 out of 30 (95 % CI [22.24, 24.43]). indicating cognitive impairment. The overall proportion of patients identified as having new onset cognitive impairment was 65 % (95 % CI [44,81]). Subgroup analyses indicated that time since infection significantly improves overall MoCA score and reduces proportion of patients with cognitive impairment.

CONCLUSION

This study indicates that cognitive impairment may be an important sequela of COVID-19. Further research with adequate sample sizes is warranted regarding COVID-19's association with new-onset dementia and dementia progression, and the effect of repeat infections. There is a need for development of diagnostic and management protocols for COVID-19 patients with cognitive impairment.

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.

Infectious Neuropathies

This review explores diverse infectious etiologies of peripheral nervous system (PNS) dysfunction, spanning sensory and motor neurons, nerves, and associated structures. Progress in viral and bacterial infections reveals multifaceted mechanisms underlying neuropathies, including viral neurotoxicity and immune-mediated responses. Latest diagnostic advances facilitate early PNS complication detection, with ongoing research offering promising treatment avenues. Emerging pathogens like severe acute respiratory syndrome coronavirus 2, Zika virus, and EV-D68 highlight the evolving infectious neuropathy paradigm. Recognizing characteristic patterns and integrating clinical factors are pivotal for precise diagnosis and tailored intervention. Challenges persist in assessment and management due to varied pathogenic mechanisms. Advancements in understanding pathogenesis have improved targeted therapies, yet gaps remain in effective treatments. Ongoing research is crucial for optimizing approaches and improving patient outcomes.

Post-COVID-19 memory complaints: Prevalence and associated factors

INTRODUCTION

Memory complaints resulting from COVID-19 may have a significant impact on the survivors' quality of life. Unfortunately, there is insufficient information available on memory loss and its relationship to COVID-19. Therefore, the purpose of this research was to determine the prevalence of memory complaints in post-COVID-19 patients and to find potential contributing factors.

METHOD

A cross-sectional survey was conducted on 401 individuals who had previously been diagnosed with COVID-19 at four COVID testing centers situated across Bangladesh. The MAC-Q questionnaire was used to evaluate memory. A binary logistic regression model was fit to study the variables related to memory complaints, with a p-value of <0.05 deemed statistically significant.

RESULT

Memory complaints was prevalent in 19.2% of the post-COVID patients. Individual predictor analysis revealed that among the treatment modalities, steroids and antibiotics were associated with impaired memory. Multiple logistic regression showed that individuals who recovered from COVID-19 within six to twelve months were more likely to have memory deficits. Even though age, sex, oxygen demand, and hospitalization were not linked with memory complaints, rural residents exhibited more significant memory complaints than urban residents.

CONCLUSION

Nearly one-fifth of the COVID-19 patients suffer from various degrees of memory complaints within one year. However, no association was found between COVID-19 severity to memory complaints.

The prognostic role of Neurologic Pupil Index in COVID-19 patients: a retrospective study

BACKGROUND

Neurological complications have been observed in approximately 30% of hospitalized COVID-19 patients. The aim of this study was to evaluate whether early assessment of the Neurological Pupil Index (NPiTM) derived from an automated pupillometry could predict mortality in critically ill COVID-19 patients.

METHODS

Retrospective cohort study of adult critically ill COVID-19 patients admitted to the intensive care unit of a University Hospital; patients without NPi measurement were excluded. The worst NPi (i.e. lowest value from one eye) was collected daily and then computed over the first five days of assessment. Mortality was assessed at hospital discharge. The secondary endpoint involved assessing differences in neurological assessments between patients who developed neurological complications and those who did not.

RESULTS

A total of 217 patients were included over the study period (median age 61 [50-68] years), 70% were males. A total of 97 patients (45%) died during the hospital stay. Among all patients, 35 (16%) experienced neurological complications. Non-survivors showed significantly a lower overall NPi (3.0 [2.0-4.1] vs. 3.4 [2.7-4.2]; P=0.04) than survivors. At multivariate logistic regression NPi was not significantly associated with in-hospital mortality. Moreover, no differences in different NPi measurements were observed between patients with and without neurological complications.

CONCLUSIONS

In this study, NPi values were not independent predictor of mortality and neurological complications in critically ill COVID-19 patients.

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.

The Role of ACE2 in Neurological Disorders: From Underlying Mechanisms to the Neurological Impact of COVID-19

Angiotensin-converting enzyme 2 (ACE2) has become a hot topic in neuroscience research in recent years, especially in the context of the global COVID-19 pandemic, where its role in neurological diseases has received widespread attention. ACE2, as a multifunctional metalloprotease, not only plays a critical role in the cardiovascular system but also plays an important role in the protection, development, and inflammation regulation of the nervous system. The COVID-19 pandemic further highlights the importance of ACE2 in the nervous system. SARS-CoV-2 enters host cells by binding to ACE2, which may directly or indirectly affect the nervous system, leading to a range of neurological symptoms. This review aims to explore the function of ACE2 in the nervous system as well as its potential impact and therapeutic potential in various neurological diseases, providing a new perspective for the treatment of neurological disorders.

COVID-19 is associated with changes in brain function and structure: A multimodal meta-analysis of neuroimaging studies

The actual role of coronavirus disease 2019 (COVID-19) in brain damage has been increasingly reported, necessitating a meta-analysis to collate and summarize the inconsistent findings from functional imaging and voxel-based morphometry (VBM) studies. A comprehensive voxel-wise meta-analysis of the whole brain was conducted to identify alterations in functional activity and gray matter volume (GMV) between COVID-19 patients and healthy controls (HCs) by using Seed-based d Mapping software. We included 15 functional imaging studies (484 patients with COVID-19, 534 HCs) and 9 VBM studies (449 patients with COVID-19, 388 HCs) in the analysis. Overall, patients with COVID-19 exhibited decreased functional activity in the right superior temporal gyrus (STG) (extending to the right middle and inferior temporal gyrus, insula, and temporal pole [TP]), left insula, right orbitofrontal cortex (OFC) (extending to the right olfactory cortex), and left cerebellum compared to HCs. For VBM, patients with COVID-19, relative to HCs, showed decreased GMV in the bilateral anterior cingulate cortex/medial prefrontal cortex (extending to the bilateral OFC), and left cerebellum, and increased GMV in the bilateral amygdala (extending to the bilateral hippocampus, STG, TP, MTG, and right striatum). Moreover, overlapping analysis revealed that patients with COVID-19 exhibited both decreased functional activity and increased GMV in the right TP (extending to the right STG). The multimodal meta-analysis suggests that brain changes of function and structure in the temporal lobe, OFC and cerebellum, and functional or structural alterations in the insula and the limbic system in COVID-19. These findings contribute to a better understanding of the pathophysiology of brain alterations in COVID-19. SIGNIFICANCE STATEMENT: This first large-scale multimodal meta-analysis collates existing neuroimaging studies and provides voxel-wise functional and structural whole-brain abnormalities in COVID-19. Findings of this meta-analysis provide valuable insights into the dynamic brain changes (from infection to recovery) and offer further explanations for the pathophysiological basis of brain alterations in COVID-19.

Objective and subjective cognitive outcomes one year after COVID-19

OBJECTIVE

This study aimed to evaluate subjective cognitive, physical, and mental health symptoms as well as objective cognitive deficits in COVID-19 patients 1 year after infection.

METHODS

This was a cross-sectional study. Seventy-four patients, who contracted a SARS-CoV-2 infection in 2020, underwent an in-person neuropsychological assessment in 2021. This included standardized tests of memory, attention, and executive functions. In addition, participants also responded to scales on subjective attention deficits, mental health symptoms, and fatigue. Patients' scores were compared to published norms.

RESULTS

Patients (N = 74) had a median age of 56 years (42% female). According to the initial disease severity, they were classified as mild (outpatients, 32%), moderate (hospitalized, non-ICU-admitted, 45%), or severe (ICU-admitted, 23%). Hospitalized patients were more often affected than outpatients. In general, deficits were most common in attention (23%), followed by memory (15%) and executive functions (3%). Patients reported increased levels of fatigue (51%), anxiety (30%), distractibility in everyday situations (20%), and depression (15%). An additional analysis suggested an association between lower scores in an attention task and hyperferritinemia. As indicated by a hierarchical regression analysis, subjective distractibility was significantly predicted by current anxiety and fatigue symptoms but not by objective attention performance (final model, adj-R 2 = 0.588, P < 0.001).

INTERPRETATION

One year after infection, COVID-19 patients can have frequent attention deficits and can complain about symptoms such as fatigue, anxiety, and distractibility. Anxiety and fatigue, more than objective cognitive deficits, have an impact on the patients' experienced impairments in everyday life.

Radiographers' workload and burnout on performance: an empirical study

Study purpose

To assess the prevalence of burnout among radiographers, and whether demographic variables and work-related factors had any influence on burnout and perceived stress among them.

Methods

A cross-sectional quantitative survey design is adopted in this study. The participants included radiographers from Saudi Arabia. Both Maslach Burnout Inventory (MBI) and Perceived Stress Scale (PSS) were used for data collection. Participation was voluntary, and the survey was conducted online, resulting in 322 final responses considered for the data analysis.

Results

The mean emotional exhaustion (EE) score achieved was 26.01, representing medium burnout risk. However, the mean depersonalization (DP: μ = 25.25) and personal accomplishment (PA: μ = 23.65) represented high burnout risk among radiographers. Statistically significant differences (p < 0.05) were observed among the participants grouped by genders, age groups, nature of work type, and work experience. The mean perceived stress score for radiographers was identified to be 27.8, indicating high.

Conclusion

The findings underscore the critical need for targeted interventions and support mechanisms within the radiology profession, particularly focusing on younger radiographers and those with extensive work experience.

Blood-brain barrier injury and neuroinflammation induced by SARS-CoV-2 in a lung-brain microphysiological system

In some patients, COVID-19 can trigger neurological symptoms with unclear pathogenesis. Here we describe a microphysiological system integrating alveolus and blood-brain barrier (BBB) tissue chips that recapitulates neuropathogenesis associated with infection by SARS-CoV-2. Direct exposure of the BBB chip to SARS-CoV-2 caused mild changes to the BBB, and infusion of medium from the infected alveolus chip led to more severe injuries on the BBB chip, including endothelial dysfunction, pericyte detachment and neuroinflammation. Transcriptomic analyses indicated downregulated expression of the actin cytoskeleton in brain endothelium and upregulated expression of inflammatory genes in glial cells. We also observed early cerebral microvascular damage following lung infection with a low viral load in the brains of transgenic mice expressing human angiotensin-converting enzyme 2. Our findings suggest that systemic inflammation is probably contributing to neuropathogenesis following SARS-CoV-2 infection, and that direct viral neural invasion might not be a prerequisite for this neuropathogenesis. Lung-brain microphysiological systems should aid the further understanding of the systemic effects and neurological complications of viral infection.

Neuropsychiatric complications of coronavirus disease 2019: Mount Sinai Health System cohort study

OBJECTIVE

To describe the frequency of neuropsychiatric complications among hospitalized patients with coronavirus disease 2019 (COVID-19) and their association with pre-existing comorbidities and clinical outcomes.

METHODS

We retrospectively identified all patients hospitalized with COVID-19 within a large multicenter New York City health system between March 15, 2020 and May 17, 2021 and randomly selected a representative cohort for detailed chart review. Clinical data, including the occurrence of neuropsychiatric complications (categorized as either altered mental status [AMS] or other neuropsychiatric complications) and in-hospital mortality, were extracted using an electronic medical record database and individual chart review. Associations between neuropsychiatric complications, comorbidities, laboratory findings, and in-hospital mortality were assessed using multivariate logistic regression.

RESULTS

Our study cohort consisted of 974 patients, the majority were admitted during the first wave of the pandemic. Patients were treated with anticoagulation (88.4%), glucocorticoids (24.8%), and remdesivir (10.5%); 18.6% experienced severe COVID-19 pneumonia (evidenced by ventilator requirement). Neuropsychiatric complications occurred in 58.8% of patients; 39.8% experienced AMS; and 19.0% experienced at least one other complication (seizures in 1.4%, ischemic stroke in 1.6%, hemorrhagic stroke in 1.0%) or symptom (headache in 11.4%, anxiety in 6.8%, ataxia in 6.3%). Higher odds of mortality, which occurred in 22.0%, were associated with AMS, ventilator support, increasing age, and higher serum inflammatory marker levels. Anticoagulant therapy was associated with lower odds of mortality and AMS.

CONCLUSION

Neuropsychiatric complications of COVID-19, especially AMS, were common, varied, and associated with in-hospital mortality in a diverse multicenter cohort at an epicenter of the COVID-19 pandemic.

COVID-19: Post infection implications in different age groups, mechanism, diagnosis, effective prevention, treatment, and recommendations

SARS-CoV-2 is a highly contagious pathogen that predominantly caused the COVID-19 pandemic. The persistent effects of COVID-19 are defined as an inflammatory or host response to the virus that begins four weeks after initial infection and persists for an undetermined length of time. Chronic effects are more harmful than acute ones thus, this review explored the long-term effects of the virus on various human organs, including the pulmonary, cardiovascular, and neurological, reproductive, gastrointestinal, musculoskeletal, endocrine, and lymphoid systems and found that SARS-CoV-2 adversely affects these organs of older adults. Regarding diagnosis, the RT-PCR is a gold standard method of diagnosing COVID-19; however, it requires specialized equipment and personnel for performing assays and a long time for results production. Therefore, to overcome these limitations, artificial intelligence employed in imaging and microfluidics technologies is the most promising in diagnosing COVID-19. Pharmacological and non-pharmacological strategies are the most effective treatment for reducing the persistent impacts of COVID-19 by providing immunity to post-COVID-19 patients by reducing cytokine release syndrome, improving the T cell response, and increasing the circulation of activated natural killer and CD8 T cells in blood and tissues, which ultimately reduces fever, nausea, fatigue, and muscle weakness and pain. Vaccines such as inactivated viral, live attenuated viral, protein subunit, viral vectored, mRNA, DNA, or nanoparticle vaccines significantly reduce the adverse long-term virus effects in post-COVID-19 patients; however, no vaccine was reported to provide lifetime protection against COVID-19; consequently, protective measures such as physical separation, mask use, and hand cleansing are promising strategies. This review provides a comprehensive knowledge of the persistent effects of COVID-19 on people of varying ages, as well as diagnosis, treatment, vaccination, and future preventative measures against the spread of SARS-CoV-2.

Promising Strategies to Reduce the SARS-CoV-2 Amyloid Deposition in the Brain and Prevent COVID-19-Exacerbated Dementia and Alzheimer's Disease

The COVID-19 pandemic, caused by infection with the SARS-CoV-2 virus, is associated with cognitive impairment and Alzheimer's disease (AD) progression. Once it enters the brain, the SARS-CoV-2 virus stimulates accumulation of amyloids in the brain that are highly toxic to neural cells. These amyloids may trigger neurological symptoms in COVID-19. The meningeal lymphatic vessels (MLVs) play an important role in removal of toxins and mediate viral drainage from the brain. MLVs are considered a promising target to prevent COVID-19-exacerbated dementia. However, there are limited methods for augmentation of MLV function. This review highlights new discoveries in the field of COVID-19-mediated amyloid accumulation in the brain associated with the neurological symptoms and the development of promising strategies to stimulate clearance of amyloids from the brain through lymphatic and other pathways. These strategies are based on innovative methods of treating brain dysfunction induced by COVID-19 infection, including the use of photobiomodulation, plasmalogens, and medicinal herbs, which offer hope for addressing the challenges posed by the SARS-CoV-2 virus.

Inflammatory Response and Defects on Myelin Integrity in the Olfactory System of K18hACE2 Mice Infected with SARS-CoV-2

Viruses, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), use respiratory epithelial cells as an entry point for infection. Within the nasal cavity, the olfactory epithelium (OE) is particularly sensitive to infections which may lead to olfactory dysfunction. In patients suffering from coronavirus disease 2019, deficits in olfaction have been characterized as a distinctive symptom. Here, we used the K18hACE2 mice to study the spread of SARS-CoV-2 infection and inflammation in the olfactory system (OS) after 7 d of infection. In the OE, we found that SARS-CoV-2 selectively targeted the supporting/sustentacular cells (SCs) and macrophages from the lamina propria. In the brain, SARS-CoV-2 infected some microglial cells in the olfactory bulb (OB), and there was a widespread infection of projection neurons in the OB, piriform cortex (PC), and tubular striatum (TuS). Inflammation, indicated by both elevated numbers and morphologically activated IBA1+ cells (monocyte/macrophage lineages), was preferentially increased in the OE septum, while it was homogeneously distributed throughout the layers of the OB, PC, and TuS. Myelinated OS axonal tracts, the lateral olfactory tract, and the anterior commissure, exhibited decreased levels of 2',3'-cyclic-nucleotide 3'-phosphodiesterase, indicative of myelin defects. Collectively, our work supports the hypothesis that SARS-CoV-2 infected SC and macrophages in the OE and, centrally, microglia and subpopulations of OS neurons. The observed inflammation throughout the OS areas and central myelin defects may account for the long-lasting olfactory deficit.

Evidences of neurological injury caused by COVID-19 from glioma tissues and glioma organoids

INTRODUCTION

Despite the extensive neurological symptoms induced by COVID-19 and the identification of SARS-CoV-2 in post-mortem brain samples from COVID-19 patients months after death, the precise mechanisms of SARS-CoV-2 invasion into the central nervous system remain unclear due to the lack of research models.

METHODS

We collected glioma tissue samples from glioma patients who had a recent history of COVID-19 and examined the presence of the SARS-CoV-2 spike protein. Subsequently, spatial transcriptomic analyses were conducted on normal brain tissues, glioma tissues, and glioma tissues from glioma patients with recent COVID-19 history. Additionally, single-cell sequencing data from both glioma tissues and glioma organoids were collected and analyzed. Glioma organoids were utilized to evaluate the efficacy of potential COVID-19 blocking agents.

RESULTS

Glioma tissues from glioma patients with recent COVID-19 history exhibited the presence of the SARS-CoV-2 spike protein. Differences between glioma tissues from glioma patients who had a recent history of COVID-19 and healthy brain tissues primarily manifested in neuronal cells. Notably, neuronal cells within glioma tissues of COVID-19 history demonstrated heightened susceptibility to Alzheimer's disease, depression, and synaptic dysfunction, indicative of neuronal aberrations. Expressions of SARS-CoV-2 entry factors were confirmed in both glioma tissues and glioma organoids. Moreover, glioma organoids were susceptible to pseudo-SARS-CoV-2 infection and the infections could be partly blocked by the potential COVID-19 drugs.

CONCLUSIONS

Gliomas had inherent traits that render them susceptible to SARS-CoV-2 infection, leading to their representability of COVID-19 neurological symptoms. This established a biological foundation for the rationality and feasibility of utilization of glioma organoids as research and blocking drug testing model in SARS-CoV-2 infection within the central nervous system.

Brain exposure to SARS-CoV-2 virions perturbs synaptic homeostasis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with short- and long-term neurological complications. The variety of symptoms makes it difficult to unravel molecular mechanisms underlying neurological sequalae after coronavirus disease 2019 (COVID-19). Here we show that SARS-CoV-2 triggers the up-regulation of synaptic components and perturbs local electrical field potential. Using cerebral organoids, organotypic culture of human brain explants from individuals without COVID-19 and post-mortem brain samples from individuals with COVID-19, we find that neural cells are permissive to SARS-CoV-2 to a low extent. SARS-CoV-2 induces aberrant presynaptic morphology and increases expression of the synaptic components Bassoon, latrophilin-3 (LPHN3) and fibronectin leucine-rich transmembrane protein-3 (FLRT3). Furthermore, we find that LPHN3-agonist treatment with Stachel partially restored organoid electrical activity and reverted SARS-CoV-2-induced aberrant presynaptic morphology. Finally, we observe accumulation of relatively static virions at LPHN3-FLRT3 synapses, suggesting that local hindrance can contribute to synaptic perturbations. Together, our study provides molecular insights into SARS-CoV-2-brain interactions, which may contribute to COVID-19-related neurological disorders.

Research progress of post-acute sequelae after SARS-CoV-2 infection

SARS-CoV-2 has spread rapidly worldwide and infected hundreds of millions of people worldwide. With the increasing number of COVID-19 patients discharged from hospitals, the emergence of its associated complications, sequelae, has become a new global health crisis secondary to acute infection. For the time being, such complications and sequelae are collectively called "Post-acute sequelae after SARS-CoV-2 infection (PASC)", also referred to as "long COVID" syndrome. Similar to the acute infection period of COVID-19, there is also heterogeneity in PASC. This article reviews the various long-term complications and sequelae observed in multiple organ systems caused by COVID-19, pathophysiological mechanisms, diagnosis, and treatment of PASC, aiming to raise awareness of PASC and optimize management strategies.

Effects of prenatal psychosocial stress and COVID-19 infection on infant attention and socioemotional development

BACKGROUND

The COVID-19 pandemic dramatically altered the psychosocial environment of pregnant women and new mothers. In addition, prenatal infection is a known risk factor for altered fetal development. Here we examine joint effects of maternal psychosocial stress and COVID-19 infection during pregnancy on infant attention at 6 months postpartum.

METHOD

One-hundred and sixty-seven pregnant mothers and infants (40% non-White; n = 71 females) were recruited in New York City (n = 50 COVID+, n = 117 COVID-). Infants' attentional processing was assessed at 6 months, and socioemotional function and neurodevelopmental risk were evaluated at 12 months.

RESULTS

Maternal psychosocial stress and COVID-19 infection during pregnancy jointly predicted infant attention at 6 months. In mothers reporting positive COVID-19 infection, higher prenatal psychosocial stress was associated with lower infant attention at 6 months. Exploratory analyses indicated that infant attention in turn predicted socioemotional function and neurodevelopmental risk at 12 months.

CONCLUSIONS

These data suggest that maternal psychosocial stress and COVID-19 infection during pregnancy may have joint effects on infant attention at 6 months. This work adds to a growing literature on the effects of the COVID-19 pandemic on infant development, and may point to maternal psychosocial stress as an important target for intervention.

IMPACT

This study found that elevated maternal psychosocial stress and COVID-19 infection during pregnancy jointly predicted lower infant attention scores at 6 months, which is a known marker of risk for neurodevelopmental disorder. In turn, infant attention predicted socioemotional function and risk for neurodevelopmental disorder at 12 months. These data suggest that maternal psychosocial stress may modulate the effects of gestational infection on neurodevelopment and highlight malleable targets for intervention.

Is there an immunological cross-reactivity of antibodies to the myelin oligodendrocyte glycoprotein and coronaviruses?

Recent reports indicated that myelin oligodendrocyte glycoprotein antibody-associated disease might be a rare complication after severe acute respiratory syndrome coronavirus 2 infection or vaccination. It is unclear whether this is an unspecific sequel of infection or vaccination or caused by possible immunological cross-reactivity of severe acute respiratory syndrome coronavirus 2 proteins and myelin oligodendrocyte glycoprotein. The aim of this study was therefore to elucidate whether there is an immunological cross-reactivity between severe acute respiratory syndrome coronavirus 2 spike or nucleocapsid proteins and myelin oligodendrocyte glycoprotein and to explore the relation of antibody responses against myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 and other coronaviruses. We analysed serum samples from patients with severe acute respiratory syndrome coronavirus 2 infection and neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 12) or without myelin oligodendrocyte glycoprotein-antibodies (n = 10); severe acute respiratory syndrome coronavirus 2 infection without neurological symptoms (n = 32); vaccinated patients with no history of severe acute respiratory syndrome coronavirus 2 infection and neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 10) or without myelin oligodendrocyte glycoprotein-antibodies (n = 9); and severe acute respiratory syndrome coronavirus 2 negative/naïve unvaccinated patients with neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 47) or without myelin oligodendrocyte glycoprotein-antibodies (n = 20). All samples were analysed for serum antibody responses to myelin oligodendrocyte glycoprotein, severe acute respiratory syndrome coronavirus 2, and other common coronaviruses (CoV-229E, CoV-HKU1, CoV-NL63 and CoV-OC43). Based on sample amount and antibody titres, 21 samples were selected for analysis of antibody cross-reactivity between myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 spike and nucleocapsid proteins using affinity purification and pre-absorption. Whereas we found no association of immunoglobulin G and A myelin oligodendrocyte glycoprotein antibodies with coronavirus antibodies, infections with severe acute respiratory syndrome coronavirus 2 correlated with an increased immunoglobulin M myelin oligodendrocyte glycoprotein antibody response. Purified antibodies showed no cross-reactivity between severe acute respiratory syndrome coronavirus 2 spike protein and myelin oligodendrocyte glycoprotein. However, one sample of a patient with myelin oligodendrocyte glycoprotein antibody-associated disease following severe acute respiratory syndrome coronavirus 2 infection showed a clear immunoglobulin G antibody cross-reactivity to severe acute respiratory syndrome coronavirus 2 nucleocapsid protein and myelin oligodendrocyte glycoprotein. This patient was also seropositive for other coronaviruses and showed immunological cross-reactivity of severe acute respiratory syndrome coronavirus 2 and CoV-229E nucleocapsid proteins. Overall, our results indicate that an immunoglobulin G antibody cross-reactivity between myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 proteins is rare. The presence of increased myelin oligodendrocyte glycoprotein-immunoglobulin M antibodies after severe acute respiratory syndrome coronavirus 2 infection may either be a consequence of a previous infection with other coronaviruses or arise as an unspecific sequel after viral infection. Furthermore, our data indicate that myelin oligodendrocyte glycoprotein-immunoglobulin A and particularly myelin oligodendrocyte glycoprotein-immunoglobulin M antibodies are a rather unspecific sequel of viral infections. Finally, our findings do not support a causative role of coronavirus infections for the presence of myelin oligodendrocyte glycoprotein-immunoglobulin G antibodies.

COVID-19 vaccination and the risk of autoimmune diseases: a Mendelian randomization study

Background

In recent times, reports have emerged suggesting that a variety of autoimmune disorders may arise after the coronavirus disease 2019 (COVID-19) vaccination. However, causality and underlying mechanisms remain unclear.

Methods

We collected summary statistics of COVID-19 vaccination and 31 autoimmune diseases from genome-wide association studies (GWAS) as exposure and outcome, respectively. Random-effects inverse variance weighting (IVW), MR Egger, weighted median, simple mode, and weighted mode were used as analytical methods through Mendelian randomization (MR), and heterogeneity and sensitivity analysis were performed.

Results

We selected 72 instrumental variables for exposure (p < 5 × 10-6; r2 < 0.001, genetic distance = 10,000 kb), and MR analyses showed that COVID-19 vaccination was causally associated with an increased risk of multiple sclerosis (MS) (IVW, OR: 1.53, 95% CI: 1.065-2.197, p = 0.026) and ulcerative colitis (UC) (IVW, OR: 1.00, 95% CI: 1.000-1.003, p = 0.039). If exposure was refined (p < 5 × 10-8; r2 < 0.001, genetic distance = 10,000 kb), the associations became negative. No causality was found for the remaining outcomes. These results were robust to sensitivity and heterogeneity analyses.

Conclusion

Our study provided potential evidence for the impact of COVID-19 vaccination on the risk of MS and UC occurrence, but it lacks sufficient robustness, which could provide a new idea for public health policy.

COVID-19 and Alzheimer's disease: Impact of lockdown and other restrictive measures during the COVID-19 pandemic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection initially results in respiratory distress symptoms but can also lead to central nervous system (CNS) and neurological manifestations, significantly impacting coronavirus disease 2019 (COVID-19) patients with neurodegenerative diseases. Additionally, strict lockdown measures introduced to curtail the spread of COVID-19 have raised concerns over the wellbeing of patients with dementia and/or Alzheimer's disease. The aim of this review was to discuss the overlapping molecular pathologies and the potential bidirectional relationship between COVID-19 and Alzheimer's dementia, as well as the impact of lockdown/restriction measures on the neuropsychiatric symptoms (NPS) of patients with Alzheimer's dementia. Furthermore, we aimed to assess the impact of lockdown measures on the NPS of caregivers, exploring its potential effects on the quality and extent of care they provide to dementia patients.We utilized the PubMed and Google Scholar databases to search for articles on COVID-19, dementia, Alzheimer's disease, lockdown, and caregivers. Our review highlights that patients with Alzheimer's disease face an increased risk of COVID-19 infection and complications. Additionally, these patients are likely to experience greater cognitive decline. It appears that these issues are primarily caused by the SARS-CoV-2 infection and appear to be further exacerbated by restrictive/lockdown measures. Moreover, lockdown measures introduced during the pandemic have negatively impacted both the NPSs of caregivers and their perception of the wellbeing of their Alzheimer's patients. Thus, additional safeguard measures, along with pharmacological and non-pharmacological approaches, are needed to protect the wellbeing of dementia patients and their caregivers in light of this and possible future pandemics.

Blood-brain barrier disruption and sustained systemic inflammation in individuals with long COVID-associated cognitive impairment

Vascular disruption has been implicated in coronavirus disease 2019 (COVID-19) pathogenesis and may predispose to the neurological sequelae associated with long COVID, yet it is unclear how blood-brain barrier (BBB) function is affected in these conditions. Here we show that BBB disruption is evident during acute infection and in patients with long COVID with cognitive impairment, commonly referred to as brain fog. Using dynamic contrast-enhanced magnetic resonance imaging, we show BBB disruption in patients with long COVID-associated brain fog. Transcriptomic analysis of peripheral blood mononuclear cells revealed dysregulation of the coagulation system and a dampened adaptive immune response in individuals with brain fog. Accordingly, peripheral blood mononuclear cells showed increased adhesion to human brain endothelial cells in vitro, while exposure of brain endothelial cells to serum from patients with long COVID induced expression of inflammatory markers. Together, our data suggest that sustained systemic inflammation and persistent localized BBB dysfunction is a key feature of long COVID-associated brain fog.

Persistent hypernatremia secondary to adipsic central diabetes insipidus in a patient with herpes-induced meningoencephalitis and COVID-19 infection: a case report

Central diabetes insipidus (CDI) typically manifests as a polyuria-polydipsia syndrome, in which normonatremia is generally maintained through the polydipsia. A 53-year-old woman presented with diabetic ketosis and hyperosmolar hyperglycemic syndrome. Her medical history included herpes meningoencephalitis, which was associated with confusion and amnesia. On physical examination, she was apyretic, confused, and had signs of extracellular dehydration. Her capillary glucose concentration was high and her urine was positive for ketones. Laboratory investigations revealed severe hyperglycemia, hypernatremia (plasma hyperosmolarity of 393.6 mOsm/L), and mild acute renal failure. In addition, she had a paucisymptomatic COVID-19 infection. Intravenous rehydration with isotonic saline solution and insulin therapy were effective at controlling the ketosis and ameliorating the hyperglycemia, but failed to normalize the hypernatremia and hyperosmolarity. She was not thirsty and had a urine output of 1 L/day, with urinary hypotonicity. Desmopressin administration reduced the hypernatremia and hyperosmolarity to within their normal ranges, and the patient's urinary osmolarity increased to 743 mOsm/L. Therefore, adipsic CDI was diagnosed. Endocrine investigations revealed isolated central hypothyroidism. The results of pituitary magnetic resonance imaging were normal. Thus, patients with impaired thirst may have an atypical presentation of CDI. In addition, the diagnosis of adipsic CDI is particularly challenging.

Lab-on-a-chip models of the blood-brain barrier: evolution, problems, perspectives

A great progress has been made in the development and use of lab-on-a-chip devices to model and study the blood-brain barrier (BBB) in the last decade. We present the main types of BBB-on-chip models and their use for the investigation of BBB physiology, drug and nanoparticle transport, toxicology and pathology. The selection of the appropriate cell types to be integrated into BBB-on-chip devices is discussed, as this greatly impacts the physiological relevance and translatability of findings. We identify knowledge gaps, neglected engineering and cell biological aspects and point out problems and contradictions in the literature of BBB-on-chip models, and suggest areas for further studies to progress this highly interdisciplinary field. BBB-on-chip models have an exceptional potential as predictive tools and alternatives of animal experiments in basic and preclinical research. To exploit the full potential of this technique expertise from materials science, bioengineering as well as stem cell and vascular/BBB biology is necessary. There is a need for better integration of these diverse disciplines that can only be achieved by setting clear parameters for characterizing both the chip and the BBB model parts technically and functionally.

The Growing Understanding of the Pituitary Implication in the Pathogenesis of Long COVID-19 Syndrome: A Narrative Review

Long COVID-19, also known as post-acute sequelae of SARS-CoV-2 infection, is a condition where individuals who have recovered from the acute phase of COVID-19 continue to experience a range of symptoms for weeks or even months afterward. While it was initially thought to primarily affect the respiratory system, it has become clear that Long COVID-19 can involve various organs and systems, including the endocrine system, which includes the pituitary gland. In the context of Long COVID-19, there is a growing understanding of the potential implications for the pituitary gland. The virus can directly affect the pituitary gland, leading to abnormalities in hormone production and regulation. This can result in symptoms such as fatigue, changes in appetite, and mood disturbances. Long COVID-19, the persistent and often debilitating condition following acute COVID-19 infection, may be explained by deficiencies in ACTH and Growth hormone production from the pituitary gland. Corticotropin insufficiency can result in the dysregulation of the body's stress response and can lead to prolonged feelings of stress, fatigue, and mood disturbances in Long COVID-19 patients. Simultaneously, somatotropin insufficiency can affect growth, muscle function, and energy metabolism, potentially causing symptoms such as muscle weakness, exercise intolerance, and changes in body composition. Recently, some authors have suggested the involvement of the pituitary gland in Post COVID-19 Syndrome. The exact mechanisms of viral action on infected cells remain under discussion, but inflammatory and autoimmune mechanisms are primarily implicated. The aim of our study will be to review the main pituitary complications following COVID-19 infection. Moreover, we will explain the possible involvement of the pituitary gland in the persistence of Post COVID-19 Syndrome.

Exacerbation of Pre-Existing Chronic Pain in Older Adults After SARS-CoV-2 Infection: A Single-Center, Cross-Sectional, Observational Study

Purpose

To identify the prevalence of exacerbation of pre-existing chronic pain after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and investigate the impact of exacerbated previous chronic pain on quality of life, sleep quality, anxiety and depression levels and risk factors associated with exacerbated chronic pain among elderly coronavirus disease of 2019 (COVID-19) survivors.

Patients and Methods

In this cross-sectional study, elderly COVID-19 survivors with chronic pain residing in Continuing Care Retirement Community (CCRC) were recruited from April 2023 to June 2023. Eligible individuals were divided into exacerbation and non-exacerbation groups based on the patient-reported worsening symptoms of previous chronic pain after SARS-CoV-2 infection. Baseline information, COVID-19 symptoms, laboratory parameters, characteristics of exacerbated chronic pain, quality of life, anxiety and depression levels were systematically collected.

Results

Ninety-five (95/441, 21.5%) older adults suffered from exacerbated chronic pain with a median numerical rating scale (NRS) score of 6 (4-7) on a median duration of 4.9 (4.3-5.6) months after SARS-CoV-2 infection. More participants were not vaccinated against COVID-19 (46.5%, 40/86 vs 26.1%, 86/330, P < 0.001) in exacerbation group. Exacerbation group exhibited poor quality of life (EQ5D index: 0.734 [0.536-0.862] vs 0.837 [0.716-0.942], P < 0.001), more severe anxiety (GAD-7: 2 [0-5] vs 0 [0-3], P < 0.001) and depression (PHQ-9: 4 [2-7] vs 2.5 [0-5], P < 0.001) than non-exacerbation group. Risk factors significantly associated with exacerbation of pre-existing chronic pain were neuropathic pain (aOR 4.81, 95% CI 1.73-13.32, P = 0.003), lymphocyte count (aOR 0.31, 95% CI 0.12-0.78, P = 0.013) and D-dimer levels (aOR 6.46, 95% CI 1.92-21.74, P = 0.003).

Conclusion

Our study observed a prevalence of 21.5% exacerbation of pre-existing chronic pain after SARS-CoV-2 infection, with a consequence of poor quality of life, more severe anxiety and depression. Previous chronic neuropathic pain, lower lymphocyte count and higher D-dimer levels were risk factors associated with the development of exacerbated previous chronic pain.

Incidence and risk factors of peripheral nerve injuries 3 months after ICU discharge: a retrospective study comparing COVID-19 and non-COVID-19 critically ill survivors

BACKGROUND

Peripheral nerve injuries (PNI) have been associated with prone positioning (PP) in mechanically ventilated (MV) patients with COVID-19 pneumonia. The aims of this retrospective study were to describe PNI prevalence 3 months (M3) after intensive care unit (ICU) discharge, whether patients survived COVID-19 or another critical illness, and to search for risk factors of PNI.

RESULTS

A total of 55 COVID (62 [54-69] years) and 22 non-COVID (61.5 [48-71.5] years) patients were followed at M3, after an ICU stay of respectively 15 [9-26.5] and 13.5 [10-19.8] days. PNI symptoms were reported by 23/55 (42.6%) COVID-19 and 8/22 (36%) non-COVID-19 patients (p = 0.798). As the incidence of PNI was similar in both groups, the entire population was used to determine risk factors. The MV duration predicted PNI occurrence (OR (CI95%) = 1.05 (1.01-1.10), p = 0.028), but not the ICU length of stay, glucocorticoids, or inflammation biomarkers.

CONCLUSION

In the present cohort, PNI symptoms were reported in at least one-third of the ICU survivors, in similar proportion whether patients suffered from severe COVID-19 or not.

Glymphatic system dysfunction in recovered patients with mild COVID-19: A DTI-ALPS study

Central nervous sequelae are often reported in recovered patients with COVID-19. It is not clear whether recovered COVID-19 patients have glymphatic impairment and clinical correlation. In this study, we demonstrated that mild COVID-19 patients experienced asymmetric bilateral glymphatic function decline after four months of recovery, and the decrease in glymphatic function was more obvious in older recovered patients. Our results further showed that recovered patients with right-sided glymphatic dysfunction experienced a greater proportion of cognitive decline (MoCA score <26) than patients with left-sided glymphatic dysfunction. With COVID-19 infection over 90% of the general population currently, future studies of cognitive disorders in the older population should consider the impact of COVID-19 infection.

The outcome and risk factors associated with central and peripheral nervous system involvement in hospitalized COVID-19 patients: a retrospective cohort study

Introduction

SARS-CoV-2 infection can affect any organ, including both the central nervous system (CNS) and peripheral nervous system (PNS). The aim of this study was to explore the outcome and risk factors associated with the involvement of either CNS or PNS in a cohort of hospitalized COVID-19 patients.

Methods

We performed a retrospective observational cohort study of hospitalized adult patients with COVID-19, between May 2020 and December 2022, presenting with new onset neurological disabilities any time after admission.

Results

We included 115 patients, 72 with CNS manifestations and 43 with PNS involvement. The CNS manifestations were COVID-19-associated encephalopathy, headache, neurovascular events, and seizures in 80.5, 43, 31.9, and 11.1% of patients, respectively. The neurovascular events were ischemic stroke in 17 (23.6%) patients, hemorrhagic stroke in 6 (8.3%) patients, venous thrombosis in 1 (1.4%) patient, and subarachnoid hemorrhage in 1 (1.4%) patient. Cranial nerve involvement was the most frequent PNS manifestation in 34 (79%) cases, followed by mononeuritis in 5 (11.6%) patients and polyneuropathy in 4 (9.3%) patients. The affected cranial nerves were the vestibulocochlear nerve in 26 (60.5%) patients, the olfactory nerve in 24 (55.8%) patients, the oculomotor nerves in 5 (11.6%) patients, and the facial nerve in 1 (2.3%) patient. Two patients (9.3%) presented with polyneuritis cranialis. Older age (HR = 1.02, 95% CI: 1.003-1.037, p = 0.01), COVID severity (HR = 2.53, 95% CI: 1.42-4.5, p = 0.002), ischemic cardiac disease (HR = 2.42, 95% CI: 1.05-5.6, p = 0.03), and increased D-dimers (HR = 1.00, 95% CI: 1.00-1.00, p = 0.02) were independently associated with the development of CNS manifestations. The factors associated with in-hospital mortality were age (HR = 1.059, 95% CI: 1.024-1.096, p = 0.001), C-reactive protein (HR = 1.006, 95% CI: 1.00-1.011, p = 0.03), CNS involvement (HR = 9.155, 95% CI: 1.185-70.74, p = 0.03), and leucocyte number (HR = 1.053, 95% CI: 1.026-1.081, p < 0.001).

Conclusion

COVID-19-associated encephalopathy was the most common CNS manifestation in our study, but neurovascular events are also important considering the overlap between inflammatory and prothrombotic pathways, especially in severe cases. CNS involvement was associated with in-hospital all-cause mortality. PNS findings were various, involving mostly the cranial nerves, especially the vestibulocochlear nerve.

Investigating the Potential Shared Molecular Mechanisms between COVID-19 and Alzheimer's Disease via Transcriptomic Analysis

SARS-CoV-2 caused the COVID-19 pandemic. COVID-19 may elevate the risk of cognitive impairment and even cause dementia in infected individuals; it may accelerate cognitive decline in elderly patients with dementia, possibly in Alzheimer's disease (AD) patients. However, the mechanisms underlying the interplay between AD and COVID-19 are still unclear. To investigate the underlying mechanisms and associations between AD progression and SARS-CoV-2 infection, we conducted a series of bioinformatics research into SARS-CoV-2-infected cells, COVID-19 patients, AD patients, and SARS-CoV-2-infected AD patients. We identified the common differentially expressed genes (DEGs) in COVID-19 patients, AD patients, and SARS-CoV-2-infected cells, and these DEGs are enriched in certain pathways, such as immune responses and cytokine storms. We constructed the gene interaction network with the signaling transduction module in the center and identified IRF7, STAT1, STAT2, and OAS1 as the hub genes. We also checked the correlations between several key transcription factors and the SARS-CoV-2 and COVID-19 pathway-related genes. We observed that ACE2 expression is positively correlated with IRF7 expression in AD and coronavirus infections, and interestingly, IRF7 is significantly upregulated in response to different RNA virus infections. Further snRNA-seq analysis indicates that NRGN neurons or endothelial cells may be responsible for the increase in ACE2 and IRF7 expression after SARS-CoV-2 infection. The positive correlation between ACE2 and IRF7 expressions is confirmed in the hippocampal formation (HF) of SARS-CoV-2-infected AD patients. Our findings could contribute to the investigation of the molecular mechanisms underlying the interplay between AD and COVID-19 and to the development of effective therapeutic strategies for AD patients with COVID-19.

Persistent intracranial hyper-inflammation in ruptured cerebral aneurysm after COVID-19: case report and review of the literature

BACKGROUND

The systemic manifestations of coronavirus disease 2019 (COVID-19) include hyperinflammatory reactions in various organs. Recent studies showed evidence for the frequent involvement of central nervous system in affected patients; however, little is known about clinical features of cerebrovascular diseases in childhood-onset COVID-19.

CASE PRESENTATION

A 10-year-old boy recovered from SARS-CoV-2 infection without complication. On 14 days after infection, he presented with loss of consciousness. A head computed tomography detected a ruptured cerebral aneurysm at the left posterior cerebral artery accompanying subarachnoid hemorrhage (SAH). Immediate surgical intervention did not rescue the patient, resulting in the demise 7 days after admission. Serological and genetic tests excluded the diagnosis of vasculitis and connective tissue disorders. Retrospective analysis showed markedly higher levels of interleukin (IL)-1β, IL-6 and IL-8 in the cerebrospinal fluid than the serum sample concurrently obtained. A review of literature indicated that adult patients with COVID-19 have a risk for the later development of SAH during the convalescent phase of COVID-19.

CONCLUSIONS

SAH is a severe complication of COVID-19 in children and adults who have asymptomatic cerebrovascular aneurysms. The markedly high levels of cytokines detected in the cerebrospinal fluid suggested that intracranial hyperinflammatory condition might be one of the possible mechanisms involved in the rupture of a preexisting cerebrovascular aneurysms.

Cortical GABA Levels Are Reduced in Post-Acute COVID-19 Syndrome

After recovering from the acute COVID-19 illness, a substantial proportion of people continue experiencing post-acute sequelae of COVID-19 (PASC), also termed "long COVID". Their quality of life is adversely impacted by persistent cognitive dysfunction and affective distress, but the underlying neural mechanisms are poorly understood. The present study recruited a group of mostly young, previously healthy adults (24.4 ± 5.2 years of age) who experienced PASC for almost 6 months following a mild acute COVID-19 illness. Confirming prior evidence, they reported noticeable memory and attention deficits, brain fog, depression/anxiety, fatigue, and other symptoms potentially suggestive of excitation/inhibition imbalance. Proton magnetic resonance spectroscopy (1H-MRS) was used to examine the neurochemical aspects of cell signaling with an emphasis on GABA levels in the occipital cortex. The PASC participants were compared to a control (CNT) group matched in demographics, intelligence, and an array of other variables. Controlling for tissue composition, biological sex, and alcohol intake, the PASC group had lower GABA+/water than CNT, which correlated with depression and poor sleep quality. The mediation analysis revealed that the impact of PASC on depression was partly mediated by lower GABA+/water, indicative of cortical hyperexcitability as an underlying mechanism. In addition, N-acetylaspartate (NAA) tended to be lower in the PASC group, possibly suggesting compromised neuronal integrity. Persistent neuroinflammation may contribute to the pathogenesis of PASC-related neurocognitive dysfunction.

Development trends of human organoid-based COVID-19 research based on bibliometric analysis

Coronavirus disease 2019 (COVID-19), a global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has posed a catastrophic threat to human health worldwide. Human stem cell-derived organoids serve as a promising platform for exploring SARS-CoV-2 infection. Several review articles have summarized the application of human organoids in COVID-19, but the research status and development trend of this field have seldom been systematically and comprehensively studied. In this review, we use bibliometric analysis method to identify the characteristics of organoid-based COVID-19 research. First, an annual trend of publications and citations, the most contributing countries or regions and organizations, co-citation analysis of references and sources and research hotspots are determined. Next, systematical summaries of organoid applications in investigating the pathology of SARS-CoV-2 infection, vaccine development and drug discovery, are provided. Lastly, the current challenges and future considerations of this field are discussed. The present study will provide an objective angle to identify the current trend and give novel insights for directing the future development of human organoid applications in SARS-CoV-2 infection.

Risk factors for delirium among hospitalized adults with COVID-19: A systematic review and meta-analysis of cohort studies

OBJECTIVES

This study aims to systematically assess the risk factors, the overall strength of association, and evidence quality related to delirium among adults hospitalized with COVID-19.

METHODS

A comprehensive search was conducted in thirteen databases from inception to February 10, 2023. The included databases were thoroughly searched, including PubMed, Web of Science, Proquest, Ovid MEDLINE, CINAHL, Scopus, the Cochrane Library, FMRS, Wanfang Database, Chinese Biomedical Database (CBM), China Knowledge Resource Integrated Database (CNKI), Weipu Database (VIP), and Embase. The search was limited to articles published in English and Chinese. The selected studies were screened, data were extracted, and the quality was evaluated using the Newcastle-Ottawa Scale. Meta-analysis was performed using RevMan 5.4 software. The certainty of the evidence was assessed using the GRADE criteria.

RESULTS

A total of 22 cohort studies with a sample size of 11,957 individuals were included in the analysis. Among these studies, 20 were of high quality, while the remaining 2 were of moderate quality. The risk factors that showed the strongest association with delirium were prior cognitive impairment (including dementia), mechanical ventilation, and ICU admission. Age, frailty (Clinical Frailty Scale score > 5), antipsychotic use, benzodiazepine use, neutrophil-to-lymphocyte ratio, and vasopressor use were identified as moderate risk factors for delirium. According to the GRADE evaluation, ICU admission, benzodiazepine use, neutrophil-to-lymphocyte ratio, and vasopressor use had a high-quality body of evidence, while antipsychotic usage had an intermediate-quality body of evidence. All other risk factors had a low-quality body of evidence.

CONCLUSIONS

This systematic review and meta-analysis identified several medium- to high-intensity risk factors for delirium in hospitalized adults with COVID-19. ICU admission, benzodiazepine usage, neutrophil-to-lymphocyte ratio, antipsychotic use, and vasopressor use were associated with delirium and were supported by medium- to high-quality evidence. These findings provide healthcare professionals with an evidence-based basis for managing and treating delirium in hospitalized adults with COVID-19.

Microglia influence immune responses and restrict neurologic disease in response to central nervous system infection by a neurotropic murine coronavirus

Intracranial (i.c.) inoculation of susceptible mice with a glial-tropic strain of mouse hepatitis virus (JHMV), a murine coronavirus, results in an acute encephalomyelitis followed by viral persistence in white matter tracts accompanied by chronic neuroinflammation and demyelination. Microglia serve numerous functions including maintenance of the healthy central nervous system (CNS) and are among the first responders to injury or infection. More recently, studies have demonstrated that microglia aid in tailoring innate and adaptive immune responses following infection by neurotropic viruses including flaviviruses, herpesviruses, and picornaviruses. These findings have emphasized an important role for microglia in host defense against these viral pathogens. In addition, microglia are also critical in optimizing immune-mediated control of JHMV replication within the CNS while restricting the severity of demyelination and enhancing remyelination. This review will highlight our current understanding of the molecular and cellular mechanisms by which microglia aid in host defense, limit neurologic disease, and promote repair following CNS infection by a neurotropic murine coronavirus.

The blues and rhythm

Most organisms, including humans, show daily rhythms in many aspects of physiology and behavior, and abnormalities in the rhythms are potential risk factors for various diseases. Mood disorders such as depression are no exception. Accumulating evidence suggests strong associations between circadian disturbances and the development of depression. Numerous studies have shown that interventions to circadian rhythms trigger depression-like phenotypes in human cases and animal models. Conversely, mood changes can affect circadian rhythms as symptoms of depression. Our preliminary data suggest that the phosphorylation signal pathway of the clock protein may act as a common pathway for mood and clock regulation. We hypothesize that mood regulation and circadian rhythms may influence each other and may share a common regulatory mechanism. This review provides an overview of circadian disturbances in animal models and human patients with depression.

Mechanism and treatment of olfactory dysfunction caused by coronavirus disease 2019

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the start of the pandemic, olfactory dysfunction (OD) has been reported as a common symptom of COVID-19. In some asymptomatic carriers, OD is often the first and even the only symptom. At the same time, persistent OD is also a long-term sequela seen after COVID-19 that can have a serious impact on the quality of life of patients. However, the pathogenesis of post-COVID-19 OD is still unclear, and there is no specific treatment for its patients. The aim of this paper was to review the research on OD caused by SARS-CoV-2 infection and to summarize the mechanism of action, the pathogenesis, and current treatments.

COVID-19 and Alzheimer's Disease Share Common Neurological and Ophthalmological Manifestations: A Bidirectional Risk in the Post-Pandemic Future

A growing body of evidence indicates that a neuropathological cross-talk takes place between the coronavirus disease 2019 (COVID-19) -the pandemic severe pneumonia that has had a tremendous impact on the global economy and health since three years after its outbreak in December 2019- and Alzheimer's Disease (AD), the leading cause of dementia among human beings, reaching 139 million by the year 2050. Even though COVID-19 is a primary respiratory disease, its causative agent, the so-called Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), is also endowed with high neuro-invasive potential (Neurocovid). The neurological complications of COVID-19, resulting from the direct viral entry into the Central Nervous System (CNS) and/or indirect systemic inflammation and dysregulated activation of immune response, encompass memory decline and anosmia which are typically associated with AD symptomatology. In addition, patients diagnosed with AD are more vulnerable to SARS-CoV-2 infection and are inclined to more severe clinical outcomes. In the present review, we better elucidate the intimate connection between COVID-19 and AD by summarizing the involved risk factors/targets and the underlying biological mechanisms shared by these two disorders with a particular focus on the Angiotensin-Converting Enzyme 2 (ACE2) receptor, APOlipoprotein E (APOE), aging, neuroinflammation and cellular pathways associated with the Amyloid Precursor Protein (APP)/Amyloid beta (Aβ) and tau neuropathologies. Finally, the involvement of ophthalmological manifestations, including vitreo-retinal abnormalities and visual deficits, in both COVID-19 and AD are also discussed. Understanding the common physiopathological aspects linking COVID-19 and AD will pave the way to novel management and diagnostic/therapeutic approaches to cope with them in the post-pandemic future.

Association of seizures with COVID-19 infection in underage during the pandemic: A systematic review and meta-analysis

OBJECTIVE

Coronavirus disease 2019 (COVID-19) is a contagious infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that has caused worldwide transmission. The aim of this systematic review and meta-analysis was to investigate the morbidity and characteristics of seizures after SARS-CoV-2 infection in underage (≤18 y) and to provide valuable reference material for subsequent clinical treatment.

METHODS

PubMed/MEDLINE, Cochrane, and EMBASE databases were searched up to 10th May 2023. We utilized the search strategy of medical subject headings combined with entry terms to search all related literatures.

RESULTS

The meta-analysis was performed according to PRISMA reporting guidelines. Risk of bias was assessed using the Newcastle-Ottawa Scale (NOS) and the Agency for Healthcare Research and Quality (AHRQ). A total of 12 articles were selected, including 4153 subjects and 333 seizure-prone minor patients with COVID-19. The morbidity of seizures after SARS-CoV-2 infection in immature patients was approximately 8.2 (95 % CI, 4.7%-12.4 %). By subgroup analysis, we know that the morbidity of male, Americas, with fever and first occurrence of seizures were 4.2% (95 % CI, 0.4-10.5 %), 4.6 % (95 % CI, 0.4 %-11.7 %), 5.4 % (95 % CI, 2.6 %-9.1 %) and 3.7 % (95 % CI, 0.7 %-8.2 %), respectively. Generalized seizures are the main type of seizures (80.6 %).

CONCLUSIONS

Seizures can be caused by SARS-CoV-2 infection in underage groups, with a pooled morbidity of 8.2% and a higher morbidity in females, in African regions, in febrile groups and during 2022-2023. In addition, generalized seizures being the predominant seizure type.