Neurological manifestations of SARS-CoV-2: complexity, mechanism and associated disorders

COVID-19 and cognitive impairment: a review of the emerging evidence

The recent surge of COVID-19 cases has raised concerns about its potential long-term effects on cognitive function. This review explores the growing body of research investigating the link between COVID-19 infection and cognitive impairment. Studies employing observational, longitudinal, and case-control designs reveal a concerning prevalence of cognitive impairment in survivors, affecting domains like attention, memory, executive function, and processing speed. The persistence of these deficits for months after the initial infection highlights the potential for long-term consequences. While the precise mechanisms remain under investigation, potential contributing factors include neuroinflammation, hypoxia, and psychological effects. Limitations within the current research landscape necessitate further investigation into the long-term trajectory of cognitive decline, the potential for intervention and recovery, and the role of vaccination in mitigating these effects. Understanding the multifaceted nature of this issue is crucial for developing effective strategies to ensure optimal cognitive health outcomes for COVID-19 survivors.

Impact of Severe COVID-19 on Accelerating Dementia Onset: Clinical and Epidemiological Insights

Importance

Severe COVID-19 infection has been associated with neurological complications, but its role in accelerating cognitive decline remains unclear.

Objective

To determine whether individuals hospitalized for severe COVID-19 exhibit a higher incidence of new onset cognitive impairment compared to those hospitalized for other conditions.

Design

A retrospective study emulating a target trial using Mass General Brigham electronic health records (March 2020-August 2024). The causal effect of COVID-19 hospitalization was estimated via cumulative incidence functions accounting for the competing risk of death.

Setting

Multicenter hospital-based study across the Mass General Brigham healthcare system.

Participants

A total of 221613 hospitalized patients met the eligibility criteria, including 6454 (2.0%) admitted due to COVID-19 and 215159 (98.0%) for all other conditions. Patients were excluded if they had less than three months of follow-up (due to censoring, cognitive impairment, or death), were younger than 55 years at baseline, or had no prior visit to Mass General Brigham in the year before baseline.

Main Outcomes and Measures

The primary outcome was new-onset cognitive impairment, identified via ICD codes and dementia medication prescriptions. The primary analysis estimated the hazard ratio for cognitive impairment with COVID-19 hospitalization relative to other hospitalizations, along with the risk difference at 4.5 years estimated via cumulative incidence functions. Inverse propensity score weighting was used to balance covariates (age, sex, comorbidities, hospitalization period).

Results

Among eligible patients (mean [SD] age, 69.55 [9.42] years, 55% female), those hospitalized for COVID-19 were significantly older and had more comorbidities (p < 0.05). COVID-19 hospitalization was associated with a higher risk of developing cognitive impairment (Hazard Ratio: 1.14 [95% CI: 1.02-1.30], P = 0.018). At 4.5 years, the cumulative incidence of cognitive impairment was 12.5% [95% CI: 11.3-13.5] in the COVID-19 group, compared to 11.6% [95% CI: 11.1-12.1] in the non-COVID-19 group.

Conclusions and Relevance

Severe COVID-19 infection was associated with an elevated risk of developing clinically recognized cognitive impairment. Future studies are needed to validate findings in other health care settings. Early screening and intervention for cognitive decline may help optimize long-term outcomes for COVID-19 patients.

Persistent Symptoms and Associated Risk Factors of COVID-19: A Cross-Sectional Study in Minia, Upper Egypt

Background: A significant number of COVID-19 survivors around the world have been reporting persistent symptoms following their recovery. Long COVID is recognized as a condition affecting not only the respiratory but also the gastrointestinal, cardiovascular, neurological, immune, and hematopoietic systems. Objective: This study aimed to describe persistent symptoms in COVID-19 survivors six months post-infection in Minia, Upper Egypt, and investigate associated risk factors. Methods: This observational cross-sectional study included 189 hospitalized and non-hospitalized patients previously diagnosed with COVID-19. Demographic data, symptom severity, comorbidities, and persistent symptoms were collected. A logistic regression analysis was used to identify risk factors associated with long COVID, with statistical significance set at p < 0.05. Results: In total, 68.8% of participants were women, and 83.5% of patients reported at least one ongoing symptom. The most self-reported symptoms were fatigue (73.5%) and myalgia (45.5%), followed by dyspnea (43.3%). Age was associated with an increased risk of developing long COVID (OR 1.028, 95% CI 1.003-1.054, p = 0.030). Patients who were hospitalized during the acute phase had more than twice the risks of having persistent symptoms (OR 2.384, 95% CI 1.055-5.387, p = 0.037). Conclusions: A substantial proportion of COVID-19 survivors in Minia, Upper Egypt, continues to experience persistent symptoms, primarily constitutional and neurological manifestations. Many patients reported self-medicating with unprescribed antibiotics, highlighting a need for public awareness regarding viral infections and the risks associated with improper antibiotic use.

Predictive biosignatures for hospitalization in patients with virologically confirmed COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, presents with varying severity among individuals. Both viral and host factors can influence the severity of acute and chronic COVID-19, with chronic COVID-19 commonly referred to as long COVID. SARS-CoV-2 infection can be properly diagnosed by performing real-time reverse transcription polymerase chain reaction analysis of nasal swab samples. Pulse oximetry, chest X-ray, and complete blood count (CBC) analysis can be used to assess the condition of the patient to ensure that the appropriate medical care is delivered. This study aimed to develop biosignatures that can be used to distinguish between patients who are likely to develop severe disease and require hospitalization from patients who can be safely monitored in less intensive settings.

METHODS

A retrospective investigation was conducted on 7897 adult patients with virologically confirmed SARS-CoV-2 infection between January 26, 2020, and November 30, 2023; all patients underwent comprehensive CBC testing at Taipei Veterans General Hospital. Among them, 1867 patients were independently recruited for a population study involving genome-wide genotyping of approximately 424 000 genomic variants. Therefore, the participants were divided into two patient cohorts, one with genomic data (n = 1867) and one without (n = 6030) for model validation and training, respectively.

RESULTS

We constructed and validated a biosignature model by using a combination of CBC measurements to predict subsequent hospitalization events (hazard ratio = 3.38, 95% confidence interval: 3.07-3.73 for the training cohort and 3.03 [2.46-3.73] for the validation cohort; both p < 10 -8 ). The obtained scores were used to identify the top quartile of patients, who formed the "very high risk" group with a significantly higher cumulative incidence of hospitalization (log-rank p < 10 -8 in both the training and validation cohorts). The "very high risk" group exhibited a cumulative hospitalization rate of >60%, whereas the rate for the other patients was approximately 30% over a 1.5-year period, providing a binary classification of patients with distinct hospitalization risks. To investigate the genetic factors mediating this risk, we conducted a genome-wide association study. Specific regions in chromosomes 7 and 10 and the mitochondrial chromosome (M), harboring IKAROS family zinc finger 1 ( IKZF1 ), actin binding LIM protein 1 ( ABLIM1 ), and mitochondrially encoded NADH:ubiquinone oxidoreductase core subunit 3 ( MT-ND3 ), exhibited prominent associations with binary risk classification. The identified exonic variants of IKZF1 are linked to several autoimmune diseases. Notably, people with different genotypes of the leading variants (rs4132601, rs141492519, and Affx-120744614) exhibited varying cumulative hospitalization rates after infection.

CONCLUSION

We successfully developed and validated a biosignature model of COVID-19 severe disease in virologically confirmed patients. The identified genomic variants provide new insights for infectious disease research and medical care.

Cognitive Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome-Aetiology and Potential Treatments

Systemic infection and inflammation impair mental function through a combination of altered attention and cognition. Here, we comprehensively review the relevant literature and report personal clinical observations to discuss the relationship between infection, peripheral inflammation, and cerebral and cognitive dysfunction in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Cognitive dysfunction in ME/CFS could result from low-grade persistent inflammation associated with raised pro-inflammatory cytokines. This may be caused by both infectious and non-infectious stimuli and lead to altered regional cerebral blood flow accompanied by disturbed neuronal function. Immune dysregulation that manifests as a subtle immunodeficiency or the autoimmunity targeting of one or more neuronal receptors may also be a contributing factor. Efforts to reduce low-grade systemic inflammation and viral reactivation and to improve mitochondrial energy generation in ME/CFS have the potential to improve cognitive dysfunction in this highly disabling condition.

In vivo characterization of ACE2 expression in Sprague-Dawley rats and cultured primary brain pericytes highlights the utility of Rattus norvegicus in the study of COVID-19 brain pathophysiology

A high number of COVID-19 patients report ongoing neurological impairments including headache, fatigue and memory impairments. Our understanding of COVID-19 disease mechanisms in the brain is limited and relies on post-mortem human tissues, in vitro studies in various cell lines (both human and animal) as well as preclinical studies in a variety of species. Notably the use of rats in the study of COVID-19 has been scarce in part due to early reports of low infectivity of the original Wuhan strain in mice and rats. Evidence has shown that subsequent strains that have mutated from the original strain are capable of infection in rats. Here we present an immunohistological characterization of ACE2 expression in the rat brain perivascular region. We found ACE2 to be expressed in pericytes but not endothelial cells or astrocytes in the perivascular space. We further examined the uptake of Omicron variants 1.1.529 and BA.2 receptor binding domains (RBD) of the SARS-CoV2 spike protein in primary brain pericytes derived from rats. We demonstrate that rat primary brain pericytes are susceptible to SARS-CoV2 spike protein uptake and induce functional changes in pericytes associated with a reduction in tight junction protein expression. These data provide evidence that rat primary cell responses to SARS-CoV2 infection are consistent with reports of infectivity in other species (transgenic mice expressing hACE2, ferrets, hamsters) and supports the use of this model organism with a long history of use in the study of disease which should be leveraged for study of COVID-19 in the brain.

Nanoparticle Interactions with the Blood Brain Barrier: Insights from Drosophila and Implications for Human Astrocyte Targeted Therapies

This review explores the intricate connections between Drosophila models and the human blood-brain barrier (BBB) with nanoparticle-based approaches for neurological treatment. Drosophila serves as a powerful model organism due to its evolutionary conservation of key biological processes, particularly in the context of the BBB, which is formed by glial cells that share structural and functional similarities with mammalian endothelial cells. Recent advancements in nanoparticle technology have highlighted their potential for effective drug delivery across the BBB, utilizing mechanisms such as passive diffusion, receptor-mediated transcytosis, and carrier-mediated transport. The ability to engineer nanoparticles with specific physicochemical properties-such as size, surface charge, and functionalization-enhances their targeting capabilities, particularly towards astrocytes, which play a crucial role in maintaining BBB integrity and responding to neuroinflammation. Insights gained from Drosophila studies have informed the design of personalized nanomedicine strategies aimed at treating neurodegenerative diseases, including Alzheimer's, Parkinson's disease etc. As research progresses, the integration of findings from Drosophila models with emerging humanized BBB systems will pave the way for innovative therapeutic approaches that improve drug delivery and patient outcomes in neurological disorders.

The Blood-Cerebrospinal Fluid Barrier as a Potential Entry Site for the SARS-CoV-2 Virus

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is an RNA virus responsible for coronavirus disease 2019 (COVID-19). While SARS-CoV-2 primarily targets the lungs and airways, it can also infect other organs, including the central nervous system (CNS). The aim of this study was to investigate whether the choroid plexus could serve as a potential entry site for SARS-CoV-2 into the brain. Tissue samples from 24 deceased COVID-19-positive individuals were analyzed. Reverse transcription real-time PCR (RT-qPCR) was performed on selected brain regions, including the choroid plexus, to detect SARS-CoV-2 viral RNA. Additionally, immunofluorescence staining and confocal microscopy were used to detect and localize two characteristic proteins of SARS-CoV-2: the spike protein S1 and the nucleocapsid protein. RT-qPCR analysis confirmed the presence of SARS-CoV-2 viral RNA in the choroid plexus. Immunohistochemical staining revealed viral particles localized in the epithelial cells of the choroid plexus, with the spike protein S1 detected in the late endosomes. Our findings suggest that the blood-cerebrospinal fluid (B-CSF) barrier in the choroid plexus serves as a route of entry for SARS-CoV-2 into the CNS. This study contributes to the understanding of the mechanisms underlying CNS involvement in COVID-19 and highlights the importance of further research to explore potential therapeutic strategies targeting this entry pathway.

SARS-CoV-2 Infection of the Central Nervous System: A Case Report

Central nervous system (CNS) infections caused by SARS-CoV-2 are uncommon. This case report describes the clinical progression of a 92-year-old female who developed a persistent neuroinfection associated with SARS-CoV-2. The patient initially presented with progressive fatigue, catarrhal symptoms, and a fever (38.6 °C). Initial laboratory findings revealed hypoxemia (O2 saturation 79.8%), acidosis (pH 7.3), an elevated C-reactive protein (CRP) level of 14.8 mg/L, and a high D-dimer level (2.15 µg/mL). Nasopharyngeal (NP) antigen and RT-PCR tests confirmed SARS-CoV-2 infection, and an NP swab also detected penicillin- and ampicillin-resistant Staphylococcus aureus. She was admitted for conservative management, including oxygen supplementation, IV fluids, and prophylactic anticoagulation. Subsequently, she developed neurological symptoms-lethargy, discoordination, and impaired communication-without signs of meningism. Cerebrospinal fluid (CSF) analysis identified SARS-CoV-2 RNA (Ct = 29) on RT-PCR, while bacterial cultures remained negative. Treatment was intensified to include 10% mannitol, dexamethasone, and empiric ceftriaxone. Despite these interventions, the patient remained somnolent, with a Glasgow Coma Scale (GCS) score of 10. Upon discharge, her GCS had improved to 14; however, she continued to experience lethargy and cognitive issues, commonly described as "brain fog". Inflammatory markers remained elevated (CRP 23 mg/L) and repeat RT-PCR of CSF confirmed a persistent SARS-CoV-2 presence (Ct = 31). This case underscores the potential for SARS-CoV-2 to cause prolonged CNS involvement, leading to persistent neurological impairment despite standard therapy. Further research is essential to clarify the pathophysiology of and determine optimal management for SARS-CoV-2 neuroinfections.

Neurological complications caused by SARS-CoV-2

SUMMARYSARS-CoV-2 can not only cause respiratory symptoms but also lead to neurological complications. Research has shown that more than 30% of SARS-CoV-2 patients present neurologic symptoms during COVID-19 (A. Pezzini and A. Padovani, Nat Rev Neurol 16:636-644, 2020, https://doi.org/10.1038/s41582-020-0398-3). Increasing evidence suggests that SARS-CoV-2 can invade both the central nervous system (CNS) (M.S. Xydakis, M.W. Albers, E.H. Holbrook, et al. Lancet Neurol 20: 753-761, 2021 https://doi.org/10.1016/S1474-4422(21)00182-4 ) and the peripheral nervous system (PNS) (M.N. Soares, M. Eggelbusch, E. Naddaf, et al. J Cachexia Sarcopenia Muscle 13:11-22, 2022, https://doi.org/10.1002/jcsm.12896), resulting in a variety of neurological disorders. This review summarized the CNS complications caused by SARS-CoV-2 infection, including encephalopathy, neurodegenerative diseases, and delirium. Additionally, some PNS disorders such as skeletal muscle damage and inflammation, anosmia, smell or taste impairment, myasthenia gravis, Guillain-Barré syndrome, ICU-acquired weakness, and post-acute sequelae of COVID-19 were described. Furthermore, the mechanisms underlying SARS-CoV-2-induced neurological disorders were also discussed, including entering the brain through retrograde neuronal or hematogenous routes, disrupting the normal function of the CNS through cytokine storms, inducing cerebral ischemia or hypoxia, thus leading to neurological complications. Moreover, an overview of long-COVID-19 symptoms is provided, along with some recommendations for care and therapeutic approaches of COVID-19 patients experiencing neurological complications.

Impact analysis of SARS-CoV-2 vaccination in patients treated with monoclonal antibodies: A monocentric experience

BACKGROUND

Since the discovery of SARS-CoV-2, no treatment has been able to completely eradicate the virus. The study aimed to evaluate the virological and clinical impact of the vaccination in SARS-CoV-2 infected patients treated with monoclonal antibodies (mAbs).

METHODS

This single-centre, observational, retrospective, real-life study was performed on SARS-CoV-2 symptomatic outpatients and inpatients treated with mAbs from March 2021 to November 2022 includes 726 patients. Each patient received available mAbs (bamlanivimab-etesevimab or casirivimab-indevimab or sotrovimab or tixagevimab-cilgavimab) according to the circulating virus strains. Age, comorbidities, vaccination status, death rates, duration of virological clearance, average length of stay, risk factors, and hospitalization or ICU admission were recorded.

RESULTS

Of 726 patients with complete data analyzed (median age 64), 516 outpatients and 210 inpatients were included. Vaccination status was known for all participants: 74.4 % and 51.7 % were vaccinated against SARS-CoV-2 among inpatients and outpatients, respectively. A shorter duration of virological clearance was observed in the vaccinated group, with a median of 16 days (IQR 15-17), compared to 19 days (IQR 18-21) in the unvaccinated group [HR 1.21; p < 0.032]. Multivariate analysis of virological clearance also showed statistical significance with tixagevimab cilgavimab 300 mg/300 mg (HR 2.73, p value < 0.001). No significant difference was found in worsening [OR 1,29; p = 0.57] and mortality [OR 0.65; p = 0.81] rates between vaccinated and unvaccinated patients treated with mAbs.

CONCLUSIONS

Key findings include a shorter duration of virological clearance in vaccinated outpatients but no significant differences in worsening or mortality rates between vaccinated and unvaccinated patients treated with mAbs. The study suggests a potential synergistic role of mAbs in accelerating virological clearance in vaccinated patients with mild to moderate COVID-19, with differing effects in hospitalized patients. Therefore, it is essential to implement health surveillance in high-risk patients with comorbidities in order to identify early any variants that might otherwise escape neutralizing antibodies.

Impact of SARS-CoV-2 Infection on Essential Tremor: A Retrospective Clinical and Kinematic Analysis

In the past few years, SARS-CoV-2 infection has substantially impacted public health. Alongside respiratory symptoms, some individuals have reported new neurological manifestations or a worsening of pre-existing neurological conditions. We previously documented two cases of essential tremor (ET) who experienced a deterioration in tremor following SARS-CoV-2 infection. However, the effects of SARS-CoV-2 on ET remain largely unexplored. This study aims to evaluate the impact of SARS-CoV-2 infection on a relatively broad sample of ET patients by retrospectively comparing their clinical and kinematic data collected before and after the exposure to SARS-CoV-2. We surveyed to evaluate the impact of SARS-CoV-2 infection on tremor features in ET. Subsequently, we retrospectively analysed clinical and kinematic data, including accelerometric recordings of postural and kinetic tremor. We included 36 ET patients (14 females with a mean age of 71.1 ± 10.6 years). Among the 25 patients who reported SARS-CoV-2 infection, 11 (44%) noted a subjective worsening of tremor. All patients reporting subjective tremor worsening also exhibited symptoms of long COVID, whereas the prevalence of these symptoms was lower (50%) in those without subjective exacerbation. The retrospective analysis of clinical data revealed a tremor deterioration in infected patients, which was not observed in non-infected patients. Finally, kinematic analysis revealed substantial stability of tremor features in both groups. The study highlighted a potential correlation between the SARS-CoV-2 infection and clinical worsening of ET. Long COVID contributes to a greater impact of tremor on the daily life of ET patients.

Neurovascular unit, neuroinflammation and neurodegeneration markers in brain disorders

Neurovascular unit (NVU) inflammation via activation of glial cells and neuronal damage plays a critical role in neurodegenerative diseases. Though the exact mechanism of disease pathogenesis is not understood, certain biomarkers provide valuable insight into the disease pathogenesis, severity, progression and therapeutic efficacy. These markers can be used to assess pathophysiological status of brain cells including neurons, astrocytes, microglia, oligodendrocytes, specialized microvascular endothelial cells, pericytes, NVU, and blood-brain barrier (BBB) disruption. Damage or derangements in tight junction (TJ), adherens junction (AdJ), and gap junction (GJ) components of the BBB lead to increased permeability and neuroinflammation in various brain disorders including neurodegenerative disorders. Thus, neuroinflammatory markers can be evaluated in blood, cerebrospinal fluid (CSF), or brain tissues to determine neurological disease severity, progression, and therapeutic responsiveness. Chronic inflammation is common in age-related neurodegenerative disorders including Alzheimer's disease (AD), Parkinson's disease (PD), and dementia. Neurotrauma/traumatic brain injury (TBI) also leads to acute and chronic neuroinflammatory responses. The expression of some markers may also be altered many years or even decades before the onset of neurodegenerative disorders. In this review, we discuss markers of neuroinflammation, and neurodegeneration associated with acute and chronic brain disorders, especially those associated with neurovascular pathologies. These biomarkers can be evaluated in CSF, or brain tissues. Neurofilament light (NfL), ubiquitin C-terminal hydrolase-L1 (UCHL1), glial fibrillary acidic protein (GFAP), Ionized calcium-binding adaptor molecule 1 (Iba-1), transmembrane protein 119 (TMEM119), aquaporin, endothelin-1, and platelet-derived growth factor receptor beta (PDGFRβ) are some important neuroinflammatory markers. Recent BBB-on-a-chip modeling offers promising potential for providing an in-depth understanding of brain disorders and neurotherapeutics. Integration of these markers in clinical practice could potentially enhance early diagnosis, monitor disease progression, and improve therapeutic outcomes.

Amnestic syndrome in the course of seronegative limbic encephalitis complicated by drug-resistant epilepsy: a case report

We present the case of a 35-year-old female patient admitted to the hospital with symptoms of rapidly increasing disturbances of consciousness and fever for 48 hours. A lumbar puncture, bacteriological and virological examinations, and initial imaging studies did not show abnormalities. Brain magnetic resonance imaging (MRI), repeated several times, showed hyperintense confluent lesions in both temporal lobes and atrophy of both hippocampi. General examination, cerebrospinal fluid culture, the panel of antineuronal antibodies, and tumor markers remained negative on subsequent repeats. Despite several laboratory and imaging studies, the etiology of the disease could not be established, infections were excluded, and no autoantibodies were found. A diagnosis of probable limbic encephalitis, amnestic syndrome resulting from organic brain damage, and drug-resistant epilepsy was made. The patient, with limbic encephalitis complicated by drug-resistant status epilepticus, was treated with cycles of immunoglobulin and subsequent plasmapheresis. She was then transferred to the Department of Psychiatry for diagnosis and treatment of intermittent psychotic disorders. During hospitalization, the patient was observed to have multiple epileptic seizures with temporal and frontal morphology, amnestic syndrome with confabulations, and periodic psychotic disorders with the occurrence of visual hallucinations. Antiepileptic treatment was escalated by including cenobamate in increasing doses. To control the mental disorders, duloxetine, tiapride, and cognitive function exercises were introduced. There was a slight improvement in memory, a cessation of confabulations, and an emergence of the patient's criticism of the symptoms presented. The psychotic symptoms subsided, and the number of epileptic seizures decreased. The described case portrays a unique co-occurrence of disease symptoms that are difficult to treat. It shows the therapeutic difficulties that can occur in patients with suspected autoimmune encephalitis. Furthermore, it shows the need for multispecialty care of a patient with psychotic symptoms in the course of epilepsy accompanied by amnestic syndrome.

Electrolytes, Zinc and Vitamin D3 in COVID-19 Patients with Cardiovascular Complications

INTRODUCTION

COVID-19 is strongly linked to cardiovascular disease, with direct myocardial injury and systemic inflammation as common mechanisms. Pre-existing or infection-induced cardiovascular disease worsens the outcomes for COVID-19 patients.

MATERIALS AND METHODS

To estimate the serum electrolytes (Na+, K+, Ca++, Zn) and vitamin D3, the study depended on ichroma ii device for Vitamin D3 and Chemistry Analyzer for electrolytes in patient samples.

RESULTS

A study was conducted on 192 individuals diagnosed with COVID-19, including 35 critical cases, 53 severe cases, 54 moderate cases, and 50 individuals in a control group. The age group with the highest prevalence of infection was between 50‒69 years, while the lowest prevalence was observed in those under 30 years. The study found significant decreases in calcium, potassium, sodium, zinc, and vitamin D3 levels among COVID-19 patients compared to the control group. Zinc and vitamin D3 levels showed a significant correlation with sex, with males experiencing a decline in zinc levels and females having lower vitamin D3 levels. The concentration of calcium, sodium, and zinc showed a negative correlation with age, with older patients having the lowest levels. COVID-19 patients with chronic cardiac issues and high blood pressure exhibited the lowest levels of these markers. The severity of the disease also had a detrimental impact on electrolyte levels, zinc, and vitamin D3, with critical cases showing the lowest levels. The complications such as heart failure were associated with lower levels of potassium, sodium, and zinc.

CONCLUSION

In conclusion, the study revealed significant associations between COVID-19 and decreased electrolyte levels, zinc, and vitamin D3. Sex and age were found to be correlated with these markers. Patients with chronic cardiac issues and high blood pressure exhibited the lowest levels of these markers. The severity of the disease was also linked to lower electrolyte levels, zinc, and vitamin D3. Complications such as heart failure were associated with decreased levels of potassium, sodium, and zinc.

Neurological Manifestations of Acute SARS-CoV-2 Infection in Pediatric Patients: A 3-Year Study on Differences between Pandemic Waves

This study analyzed the neurological manifestation profiles of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection across pandemic waves in pediatric patients. The study collected data on patients aged between 0 and 18 years, diagnosed with acute SARS-CoV-2 infection, admitted to a pediatric tertiary hospital between 1 March 2020 and 28 February 2023. This study included 1677 patients. Neurological manifestations were noted in 10% (n = 168) of patients with a median age of 3.2 years (interquartile range: 1-11.92). Neurological manifestations were significantly associated with the pandemic waves (p = 0.006) and age groups (p < 0.001). Seizures were noted in 4.2% of cases and reached an increasing frequency over time (p = 0.001), but were not associated with age groups. Febrile seizures accounted for the majority of seizures. Headache was reported in 2.6% of cases and had similar frequencies across the pandemic waves and age groups. Muscular involvement was noted in 2% of cases, reached a decreasing frequency over time (p < 0.001), and showed different frequencies among the age groups. Neurological manifestations of acute SARS-CoV-2 infection exhibit distinct patterns, depending on the pandemic wave and patient age group. The Wuhan and Omicron waves involved the nervous system more often than the other waves.

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.

Neuropathological lesions in intravenous BCG-stimulated K18-hACE2 mice challenged with SARS-CoV-2

In the wake of the COVID-19 pandemic caused by SARS-CoV-2, questions emerged about the potential effects of Bacillus Calmette-Guérin (BCG) vaccine on the immune response to SARS-CoV-2 infection, including the neurodegenerative diseases it may contribute to. To explore this, an experimental study was carried out in BCG-stimulated and non-stimulated k18-hACE2 mice challenged with SARS-CoV-2. Viral loads in tissues determined by RT-qPCR, histopathology in brain and lungs, immunohistochemical study in brain (IHC) as well as mortality rates, clinical signs and plasma inflammatory and coagulation biomarkers were assessed. Our results showed BCG-SARS-CoV-2 challenged mice presented higher viral loads in the brain and an increased frequency of neuroinvasion, with the greatest differences observed between groups at 3-4 days post-infection (dpi). Histopathological examination showed a higher severity of brain lesions in BCG-SARS-CoV-2 challenged mice, mainly consisting of neuroinflammation, increased glial cell population and neuronal degeneration, from 5 dpi onwards. This group also presented higher interstitial pneumonia and vascular thrombosis in lungs (3-4 dpi), BCG-SARS-CoV-2 mice showed higher values for TNF-α and D-dimer values, while iNOS values were higher in SARS-CoV-2 mice at 3-4 dpi. Results presented in this study indicate that BCG stimulation could have intensified the inflammatory and neurodegenerative lesions promoting virus neuroinvasion and dissemination in this experimental model. Although k18-hACE2 mice show higher hACE2 expression and neurodissemination, this study suggests that, although the benefits of BCG on enhancing heterologous protection against pathogens and tumour cells have been broadly demonstrated, potential adverse outcomes due to the non-specific effects of BCG should be considered.

The Neurological Implications of COVID-19: A Comprehensive Narrative Review

The COVID-19 pandemic caused by the coronavirus SARS-CoV-2 revealed a huge number of problems as well as discoveries in medicine, notably, regarding the effects of the virus on the central nervous system (CNS) and peripheral nervous system (PNS). This paper is a narrative review that takes a deep dive into the complex interactions between COVID-19 and the NS. Therefore, this paper explains the broad range of neurological manifestations and neurodegenerative diseases caused by the virus. It carefully considers the routes through which SARS-CoV-2 reaches the NS, including the olfactory system and of course, the hematogenous route, which are also covered when discussing the virus's direct and indirect mechanisms of neuropathogenesis. Besides neurological pathologies such as stroke, encephalitis, Guillain-Barré syndrome, Parkinson's disease, and multiple sclerosis, the focus area is also given to the challenges of making diagnosis, treatment, and management of these conditions during the pandemic. The review also examines the strategic and interventional approaches utilized to prevent these disorders, as well as the ACE2 receptors implicated in the mediation of neurological effects caused by COVID-19. This detailed overview, which combines research outputs with case data, is directed at tackling this pandemic challenge, with a view toward better patient care and outcomes in the future.

Factors associated with cognitive impairment and the quality-of-life among COVID-19 survivors working as healthcare workers

Prolonged physical and mental health changes, known as post-COVID conditions (PCC), could impair the quality-of-life (QoL) of healthcare workers. The aim of this study was to identify factors that contribute to cognitive impairments and QoL among COVID-19 survivors working as healthcare workers. This cross-sectional study involved healthcare workers at Prof. Dr. Chairuddin P. Lubis Universitas Sumatera Utara Hospital, Medan, Indonesia. The Montreal Cognitive Assessment (MoCA) was used to assess the cognitive function, while the World Health Organization Quality-of-Life Brief Version (WHOQOL-BREF) questionnaire was used to evaluate the QoL. Factors associated with cognitive and QoL status were examined using Mann-Whitney and Chi-squared tests. A total of 100 COVID-19 survivors were included in the study, most of whom were female (74%), aged ≤35 years (95%), and were doctors (62%). Only 22% of the participants had a normal BMI, 93% had a history of mild COVID-19, and 54% had one comorbidity. The Overall MoCA score averaged 24.18±2.86, indicating mild cognitive impairment among the groups. The distribution of MoCA scores had similar patterns with no significant differences based on age, gender, comorbidities, BMI, COVID-19 severity, and frequency of COVID-19 infection. Interestingly, the number of vaccine doses received by the participants had a statistically significant associated with MoCA scores of which those receiving more than two doses had higher cognitive scores than those with only two doses (p=0.008). Based on categorized MoCA scores (normal vs cognitive impairment), none assessed factors were not significantly associated with cognitive outcomes. The WHOQOL-BREF scores ranged from 62.5 to 95.5, with a mean±SD of 83.67±7.03. None of the assessed factors were associated with WHOQOL-BREF scores among COVID-19 survivors. These findings highlight the need for further study to explore the protective role of vaccination frequency in cognitive impairment and the factors underlying the resilience in QoL among survivors.

Elevated level of circulating calprotectin correlates with severity and high mortality in patients with COVID-19

BACKGROUND

Patients with coronavirus disease-2019 (COVID-19) are characterized by hyperinflammation. Calprotectin (S100A8/S100A9) is a calcium- and zinc-binding protein mainly secreted by neutrophilic granulocytes or macrophages and has been suggested to be correlated with the severity and prognosis of COVID-19.

AIM

To thoroughly evaluate the diagnostic and prognostic utility of calprotectin in patients with COVID-19 by analyzing relevant studies.

METHODS

PubMed, Web of Science, and Cochrane Library were comprehensively searched from inception to August 1, 2023 to retrieve studies about the application of calprotectin in COVID-19. Useful data such as the level of calprotectin in different groups and the diagnostic efficacy of this biomarker for severe COVID-19 were extracted and aggregated by using Stata 16.0 software.

RESULTS

Fifteen studies were brought into this meta-analysis. First, the pooled standardized mean differences (SMDs) were used to estimate the differences in the levels of circulating calprotectin between patients with severe and non-severe COVID-19. The results showed an overall estimate of 1.84 (95% confidence interval [CI]: 1.09-2.60). Diagnostic information was extracted from 11 studies, and the pooled sensitivity and specificity of calprotectin for diagnosing severe COVID-19 were 0.75 (95% CI: 0.64-0.84) and 0.88 (95% CI: 0.79-0.94), respectively. The AUC was 0.89 and the pooled DOR was 18.44 (95% CI: 9.07-37.51). Furthermore, there was a strong correlation between elevated levels of circulating calprotectin and a higher risk of mortality outcomes in COVID-19 patients (odds ratio: 8.60, 95% CI: 2.17-34.12; p < 0.1).

CONCLUSION

This meta-analysis showed that calprotectin was elevated in patients with severe COVID-19, and this atypical inflammatory cytokine might serve as a useful biomarker to distinguish the severity of COVID-19 and predict the prognosis.

A Comprehensive Review of COVID-19-Related Olfactory Deficiency: Unraveling Associations with Neurocognitive Disorders and Magnetic Resonance Imaging Findings

Olfactory dysfunction (OD) is one of the most common symptoms in COVID-19 patients and can impact patients' lives significantly. The aim of this review was to investigate the multifaceted impact of COVID-19 on the olfactory system and to provide an overview of magnetic resonance (MRI) findings and neurocognitive disorders in patients with COVID-19-related OD. Extensive searches were conducted across PubMed, Scopus, and Google Scholar until 5 December 2023. The included articles were 12 observational studies and 1 case report that assess structural changes in olfactory structures, highlighted through MRI, and 10 studies correlating the loss of smell with neurocognitive disorders or mood disorders in COVID-19 patients. MRI findings consistently indicate volumetric abnormalities, altered signal intensity of olfactory bulbs (OBs), and anomalies in the olfactory cortex among COVID-19 patients with persistent OD. The correlation between OD and neurocognitive deficits reveals associations with cognitive impairment, memory deficits, and persistent depressive symptoms. Treatment approaches, including olfactory training and pharmacological interventions, are discussed, emphasizing the need for sustained therapeutic interventions. This review points out several limitations in the current literature while exploring the intricate effects of COVID-19 on OD and its connection to cognitive deficits and mood disorders. The lack of objective olfactory measurements in some studies and potential validity issues in self-reports emphasize the need for cautious interpretation. Our research highlights the critical need for extensive studies with larger samples, proper controls, and objective measurements to deepen our understanding of COVID-19's long-term effects on neurological and olfactory dysfunctions.

"Multisystem Inflammatory Syndrome in Children"-Like Disease after COVID-19 Vaccination (MIS-V) with Potential Significance of Functional Active Autoantibodies Targeting G-Protein-Coupled Receptors (GPCR-fAAb) for Pathophysiology and Therapy

BACKGROUND

An infection with SARS-CoV-2 can trigger a systemic disorder by pathological autoimmune processes. A certain type of this dysregulation is known as Multisystemic inflammatory syndrome in children (MIS-C). However, similar symptoms may occur and have been described as Multisystemic inflammatory syndrome after SARS-CoV-2 Vaccination (MIS-V) following vaccination against SARS-CoV-2. We report the case of a 12-year-old boy who was identified with MIS-C symptoms without previous SARS-CoV-2 infection after receiving two doses of the Pfizer-BioNTech COVID-19 vaccine approximately one month prior to the onset of symptoms. He showed polyserositis, severe gastrointestinal symptoms and, consequently, a manifestation of a multiorgan failure. IgG antibodies against spike proteins of SARS-CoV-2 were detected, indicating a successful vaccination, while SARS-CoV-2 Nucleocapsid protein antibodies and SARS-CoV-2 PCR were not detected. Several functional, active autoantibodies against G-protein-coupled receptors (GPCR-fAAb), previously associated with Long COVID disease, were detected in a cardiomyocyte bioassay. Immunosuppression with steroids was initiated. Due to side effects, treatment with steroids and later interleukin 1 receptor antagonists had to be terminated. Instead, immunoadsorption was performed and continued with tacrolimus and mycophenolic acid therapy, leading to improvement and discharge after 79 days. GPCR-fAAb decreased during therapy and remained negative after clinical curing and under continued immunosuppressive therapy with tacrolimus and mycophenolic acid. Follow-up of the patient showed him in good condition after one year.

CONCLUSIONS

Infection with SARS-CoV-2 shows a broad and severe variety of symptoms, partly due to autoimmune dysregulation, which, in some instances, can lead to multiorgan failure. Despite its rarity, post-vaccine MIS-C-like disease may develop into a serious condition triggered by autoimmune dysregulation. The evidence of circulating GPCR-fAAb and their disappearance after therapy suggests a link of GPCR-fAAb to the clinical manifestations. Thus, we hypothesize a potential role of GPCR-fAAb in pathophysiology and their potential importance for the therapy of MIS-C or MIS-V. However, this observation needs further investigation to prove a causative correlation.

SARS-CoV-2 and Brain Health: New Challenges in the Era of the Pandemic

Respiratory viral infections have been found to have a negative impact on neurological functions, potentially leading to significant neurological impairment. The SARS-CoV-2 virus has precipitated a worldwide pandemic, posing a substantial threat to human lives. Growing evidence suggests that SARS-CoV-2 may severely affect the CNS and respiratory system. The current prevalence of clinical neurological issues associated with SARS-CoV-2 has raised significant concerns. However, there needs to be a more comprehensive understanding of the specific pathways by which SARS-CoV-2 enters the nervous system. Based on the available evidence, this review focuses on the clinical neurological manifestations of SARS-CoV-2 and the possible mechanisms by which SARS-CoV-2 invades the brain.