Does COVID-19 contribute to development of neurological disease?

Exploring the Therapeutic Potential of Terpenoids for Depression and Anxiety

This review focus on the terpenoids as potential therapeutic agents for depression and anxiety disorders, which naturally found in a variety of plants and exhibit a wide range of biological activities. Among the terpenoids discussed in this review are α-pinene, β-caryophyllene, α-phellandrene, limonene, β-linalool, 1, 8-cineole, β-pinene, caryophyllene oxide, p-cymene, and eugenol. All of these compounds have been studied extensively regarding their pharmacological properties, such as neuroprotective effect, anti-inflammation, antibacterial, regulation of neurotransmitters and antioxidant effect. Preclinical evidence are reviewed to highlight their diverse mechanisms of action and therapeutic potential to support antidepressant and anxiolytic properties. Additionally, challenges and future directions are also discussed to emphasize therapeutic utility of terpenoids for mental health disorders. Overall, this review provides a promising role of terpenoids as novel therapeutic agents for depression and anxiety, with potential implications for the development of more effective and well-tolerated treatments in the field of psychopharmacology.

Antiviral Activity of Graphene Oxide-Silver Nanocomposites Against Murine Betacoronavirus

Background

The high infectivity of coronaviruses has led to increased interest in developing new strategies to prevent virus spread. Silver nanoparticles (AgNPs) and graphene oxide (GO) have attracted much attention in the antiviral field. We investigated the potential antiviral activity of GO and AgNPs combined in the nanocomposite GO-Ag against murine betacoronavirus MHV using an in vitro model.

Methods

GO, AgNPs, and GO-Ag characterization (size distribution, zeta potential, TEM visualization, FT-IR, and EDX analysis) and XTT assay were performed. The antiviral activity of GO-Ag nanocomposites was evaluated by RT-qPCR and TCID50 assays. The results were compared with free AgNPs and pure GO. Cell growth and morphology of MHV-infected hepatocytes treated with GO-Ag composites were analyzed by JuLI™Br. Immunofluorescence was used to visualize the cell receptor used by MHV. Ultrastructural SEM analysis was performed to examine cell morphology after MHV infection and GO-Ag composite treatment.

Results

A significant reduction in virus titer was observed for all nanocomposites tested, ranging from 3.2 to 7.3 log10 TCID50. The highest titer reduction was obtained for GO 5 µg/mL - Ag 25 µg/mL in the post-treatment method. These results were confirmed by RT-qPCR analysis. The results indicate that GO-Ag nanocomposites exhibited better antiviral activity compared to AgNPs and GO. Moreover, the attachment of AgNPs to the GO flake platform reduced their cytotoxicity. In addition, the GO-Ag composite modulates the distribution of the Ceacam1 cell receptor and can modulate cell morphology.

Conclusion

Graphene oxide sheets act as a stabilizing agent, inhibiting the accumulation of AgNPs and reducing their cellular toxicity. The GO-Ag composite can physically bind and inhibit murine betacoronavirus from entering cells. Furthermore, the constant presence of GO-Ag can inhibit MHV replication and significantly limit its extracellular release. In conclusion, GO-Ag shows promise as an antiviral coating on solid surfaces to minimize virus transmission and spread.

Congenital anomalies and predisposition to severe COVID-19 among pediatric patients in the United States

BACKGROUND AND OBJECTIVE

Congenital heart defects are known to be associated with increased odds of severe COVID-19. Congenital anomalies affecting other body systems may also be associated with poor outcomes. This study is an exhaustive assessment of congenital anomalies and odds of severe COVID-19 in pediatric patients.

METHODS

Data were retrieved from the COVID-19 dataset of Cerner® Real-World Data for encounters from March 2020 to February 2022. Prior to matching, the data consisted of 664,523 patients less than 18 years old and 927,805 corresponding encounters with COVID-19 from 117 health systems across the United States. One-to-one propensity score matching was performed, and a cumulative link mixed-effects model with random intercepts for health system and patients was built to assess corresponding associations.

RESULTS

All congenital anomalies were associated with worse COVID-19 outcomes, with the strongest association observed for cardiovascular anomalies (odds ratio [OR], 3.84; 95% CI, 3.63-4.06) and the weakest association observed for anomalies affecting the eye/ear/face/neck (OR, 1.16; 95% CI, 1.03-1.31).

CONCLUSIONS AND RELEVANCE

Congenital anomalies are associated with greater odds of experiencing severe symptoms of COVID-19. In addition to congenital heart defects, all other birth defects may increase the odds for more severe COVID-19.

IMPACT

All congenital anomalies are associated with increased odds of severe COVID-19. This study is the largest and among the first to investigate birth defects across all body systems. The multicenter large data and analysis demonstrate the increased odds of severe COVID19 in pediatric patients with congenital anomalies affecting any body system. These data demonstrate that all children with birth defects are at increased odds of more severe COVID-19, not only those with heart defects. This should be taken into consideration when optimizing prevention and intervention resources within a hospital.

Fifteen acute retrobulbar optic neuritis associated with COVID-19: A case report and review of literature

BACKGROUND

A subtype of the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is suggested to be responsible for the outbreak in Northern China since the quarantine was lifted in December 2022. The coronavirus disease 2019 virus is primarily responsible for the development of respiratory illnesses, however, it can present a plethora of symptoms affecting a myriad of body organs. This virus has been theorized to be linked to demyelinating lesions of the peripheral and central nervous system including transverse myelitis and acute retrobulbar optic neuritis (ARON). For example, magnetic resonance imaging (MRI) of the orbit and brain showed enlargement of the retrobulbar intraorbital segments of the optic nerve with high T2 signal, and no abnormalities were seen in the brain tissue. In this case series, we analyzed the connection between SARS-CoV-2 infection and the onset of ARON.

CASE SUMMARY

Fifteen patients, and a teenage boy who did not have any pre-existing ocular or demyelinating diseases suddenly experienced a loss of vision after SARS-CoV-2 infection. The patients expressed a central scotoma and a fever as the primary concern. The results of the fundus photography were found to be normal. However, the automated perimetry and MRI scans showed evidence of some typical signs. Out of the 15 patients diagnosed with ARON after SARS-CoV-2 infection, only one individual tested positive for the aquaporin-4 antibody.

CONCLUSION

Direct viral invasion of the central nervous system and an immune-related process are the two primary causes of SARS-CoV-2-related ARON.

Hippocampal neurometabolic and structural changes from pre-to post-COVID-19: A case-series study

BACKGROUND

Neurological complications of the COVID-19 infection may be caused in part by local neurochemical and structural abnormalities that could not be detected during routine medical examinations. We examined within subject neurometabolic and structural brain alterations from pre-to post-COVID-19 in the hippocampal region of three elderly individuals (aged 63-68 years) who had a COVID-19 infection with mild symptoms. Patients were participating in an interventional study in which they were closely monitored at the time they were diagnosed with COVID-19. Patients 1 and 2 just completed 18-20 resistance training sessions prior to their diagnosis. Patient 3 was assigned to a non-training condition in the same study.

METHODS

Whole brain magnetic resonance imaging (MRI) images and proton magnetic resonance spectroscopy (1H-MRS) of the left hippocampus were collected before and after infection. Structural and spectroscopic imaging measures post-COVID-19 were contrasted to the pre-COVID-19 measures and were compared with values for Minimal Detectable Change at 95% (MDC95) and 90% (MDC90) confidence from a group of six elderly (aged 60-79 years) without COVID-19 that participated in the same study.

RESULTS

After SARS-COV-2 infection, we observed a reduction of glutamate-glutamine (Glx) in Patients 1 and 2 (≥ 42.0%) and elevation of myo-inositol (mIns) and N-acetyl-aspartate (NAA) in Patient 3 (≥ 36.4%); all > MDC90. MRI findings showed increased (Patients 1 and 2) or unchanged (Patient 3) hippocampal volume.

CONCLUSIONS

Overall, findings from this exploratory study suggest that mild COVID-19 infection could be associated with development of local neuroinflammation and reduced glutamate levels in the hippocampus. Our 1H-MRS findings may have clinical value for explaining chronic neurological and psychological complaints in COVID-19 long-haulers.

Subdural effusion associated with COVID-19 encephalopathy: A case report

BACKGROUND

The precise mechanism by which severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) impacts the central nervous system remains unclear, with manifestations spanning from mild symptoms (e.g., olfactory and gustatory deficits, hallucinations, and headache) to severe complications (e.g., stroke, seizures, encephalitis, and neurally demyelinating lesions). The occurrence of single-pass subdural effusion, as described below, is extremely rare.

CASE SUMMARY

A 56-year-old male patient presented with left-sided limb weakness and slurred speech as predominant clinical symptoms. Through comprehensive imaging and diagnostic assessments, he was diagnosed with cerebral infarction complicated by hemorrhagic transformation affecting the right frontal, temporal, and parietal regions. In addition, an intracranial infection with SARS-CoV-2 was identified during the rehabilitation process; consequently, an idiopathic subdural effusion developed. Remarkably, the subdural effusion underwent absorption within 6 d, with no recurrence observed during the 3-month follow-up.

CONCLUSION

Subdural effusion is a potentially rare intracranial complication associated with SARS-CoV-2 infection.

COVID-19 restrictions promoted the newly occurring loneliness in older people - a prospective study in a memory clinic population

Introduction

A high burden and many negative outcomes for older people were associated with the COVID-19 pandemic. Social isolation and loneliness are prevalent health problems impacting well-being and quality of life and may have increased due to pandemic-related restrictions. Methods: This study investigate the influence of the COVID-19 pandemic on loneliness in people visiting a mem40ory clinic between March 2020 and September 2022. We conducted a prospective, single-center, questionnaire-based observational follow-up study to assess potential predictors of newly occurring, pandemic-related loneliness. Next to a newly developed COVID-19 questionnaire, a comprehensive neuropsychological test battery, the Neuropsychiatric Inventory and the Geriatric Depression Scale were used.

Results

In total 426 people (mean age: 76.48 years, 12.9% cognitively intact, 33.1% diagnosed with Mild Cognitive Impairment, 49.8% diagnosed with dementia, and 4.2% diagnosed with depression) completed the COVID-19 questionnaire at baseline and 166 at follow-up. Newly occurring loneliness was indicated by 22.3% of baseline participants and by 24.1% of follow-up participants. Results of logistic regression analysis showed that living alone (OR 5.452) and having less contact with friends (OR 2.771) were most predictive of the occurrence of loneliness. The use of digital communication media as an alternative strategy for social interaction was lowest in dementia patients (6-13%).

Discussion

In conclusion, personal contacts and a close friendship network appear to be more decisive to prevent loneliness in older people than does the use of digital communication media. However, promoting an intensified use of digital communication media may be useful to counteract loneliness, especially in dementia patients.

SARS-CoV-2 Infection to Premature Neuronal Aging and Neurodegenerative Diseases: Is there any Connection with Hypoxia?

The pandemic of coronavirus disease-2019 (COVID-19), caused by SARS-CoV-2, has become a global concern as it leads to a spectrum of mild to severe symptoms and increases death tolls around the world. Severe COVID-19 results in acute respiratory distress syndrome, hypoxia, and multi- organ dysfunction. However, the long-term effects of post-COVID-19 infection are still unknown. Based on the emerging evidence, there is a high possibility that COVID-19 infection accelerates premature neuronal aging and increases the risk of age-related neurodegenerative diseases in mild to severely infected patients during the post-COVID period. Several studies correlate COVID-19 infection with neuronal effects, though the mechanism through which they contribute to the aggravation of neuroinflammation and neurodegeneration is still under investigation. SARS-CoV-2 predominantly targets pulmonary tissues and interferes with gas exchange, leading to systemic hypoxia. The neurons in the brain require a constant supply of oxygen for their proper functioning, suggesting that they are more vulnerable to any alteration in oxygen saturation level that results in neuronal injury with or without neuroinflammation. We hypothesize that hypoxia is one of the major clinical manifestations of severe SARS-CoV-2 infection; it directly or indirectly contributes to premature neuronal aging, neuroinflammation, and neurodegeneration by altering the expression of various genes responsible for the survival of the cells. This review focuses on the interplay between COVID-19 infection, hypoxia, premature neuronal aging, and neurodegenerative diseases and provides a novel insight into the molecular mechanisms of neurodegeneration.

The effect of COVID-19 on Multiple Sclerosis relapse: A systematic review and meta-analysis

BACKGROUND

Multiple Sclerosis (MS) is a chronic autoimmune disease, affecting over 2.5 million people worldwide. There has been growing concern about the impact of COVID-19 on the clinical course of MS. However, these findings remain controversial, and there is a lack of high-quality evidence to establish the relationship between COVID-19 and MS.

METHODS

A comprehensive search was done to identify relevant studies reporting relapse rate in patients with MS (pwMS), those comparing the relapse rate of COVID-19 pwMS and MS controls, and studies investigating the effect of COVID-19 on relapse rate of pwMS. The results were presented as proportion of COVID-19 pwMS experiencing relapse and odds ratio determining the impact of COVID-19 on relapse rate.

RESULTS

Fourteen studies were included in the analyses. The proportion of COVID-19 positive pwMS with relapse was 7.71 per 100 cases (95 % confidence interval, CI: 4.41-13.89, I2=96 %). Quantitative evaluation of studies with pwMS without COVID-19 did not demonstrate a statistically significant difference in relapse rate of patients with COVID-19 (OR: 0.75, 95 %CI: 0.44-1.29, I2= 54 %). Subgroup and sensitivity analyses did not alter the lack of significance of association between COVID-19 and MS relapse. Sensitivity analysis excluding the outlying study was largely in favor of no difference between the groups (OR:1.00, 95 %CI: 0.72-1.38, I2=34 %) CONCLUSION: The results of this review does not suggest that COVID-19 influences the relapse rate in pwMS. While the findings alleviate the concerns regarding the co-occurrence of the diseases, further studies are needed to investigate the effects of confounding factors.

COVID-19 vaccination for patients with epilepsy: A Chinese expert consensus

Coronavirus disease-2019 (COVID-19) first emerged in late 2019 and has since spread worldwide. More than 600 million people have been diagnosed with COVID-19, and over 6 million have died. Vaccination against COVID-19 is one of the best ways to protect humans. Epilepsy is a common disease, and there are approximately 10 million patients with epilepsy (PWE) in China. However, China has listed "uncontrolled epilepsy" as a contraindication for COVID-19 vaccination, which makes many PWE reluctant to get COVID-19 vaccination, greatly affecting the health of these patients in the COVID-19 epidemic. However, recent clinical practice has shown that although a small percentage of PWE may experience an increased frequency of seizures after COVID-19 vaccination, the benefits of COVID-19 vaccination for PWE far outweigh the risks, suggesting that COVID-19 vaccination is safe and recommended for PWE. Nonetheless, vaccination strategies vary for different PWE, and this consensus provides specific recommendations for PWE to be vaccinated against COVID-19.

Chronic Neurological Disorders and Predisposition to Severe COVID-19 in Pediatric Patients in the United States

BACKGROUND

We investigated the association between chronic pediatric neurological conditions and the severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

METHODS

This matched retrospective case-control study includes patients (n = 71,656) with chronic complex neurological disorders under 18 years of age, with laboratory-confirmed diagnosis of COVID-19 or a diagnostic code indicating infection or exposure to SARS-CoV-2, from 103 health systems in the United States. The primary outcome was the severity of coronavirus disease 2019 (COVID-19), which was classified as severe (invasive oxygen therapy or death), moderate (noninvasive oxygen therapy), or mild/asymptomatic (no oxygen therapy). A cumulative link mixed effects model was used for this study.

RESULTS

In this study, a cumulative link mixed effects model (random intercepts for health systems and patients) showed that the following classes of chronic neurological disorders were associated with higher odds of severe COVID-19: muscular dystrophies and myopathies (OR = 3.22; 95% confidence interval [CI]: 2.73 to 3.84), chronic central nervous system disorders (OR = 2.82; 95% CI: 2.67 to 2.97), cerebral palsy (OR = 1.97; 95% CI: 1.85 to 2.10), congenital neurological disorders (OR = 1.86; 95% CI: 1.75 to 1.96), epilepsy (OR = 1.35; 95% CI: 1.26 to 1.44), and intellectual developmental disorders (OR = 1.09; 95% CI: 1.003 to 1.19). Movement disorders were associated with lower odds of severe COVID-19 (OR = 0.90; 95% CI: 0.81 to 0.99).

CONCLUSIONS

Pediatric patients with chronic neurological disorders are at higher odds of severe COVID-19. Movement disorders were associated with lower odds of severe COVID-19.

Microstructural alterations in hypoxia-related BRAIN centers after COVID-19 by using DTI: A preliminary study

PURPOSE

To investigate whether the diffusion tensor imaging (DTI) parameters alterations in the in hypoxia-related neuroanatomical localizations in patients after COVID-19. Additionally, the relationship between DTI findings and the clinical severity of the disease is evaluated.

METHODS

The patients with COVID-19 were classified into group 1 (total patients, n = 74), group 2 (outpatient, n = 46), and group 3 (inpatient, n = 28) and control (n = 52). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were calculated from the bulbus, pons, thalamus, caudate nucleus, globus pallidum, putamen, and hippocampus. DTI parameters were compared between groups. Oxygen saturation, D dimer and lactate dehydrogenase (LDH) values associated with hypoxia were analyzed in inpatient group. Laboratory findings were correlated with ADC and FA values.

RESULTS

Increased ADC values in the thalamus, bulbus and pons were found in group 1 compared to control. Increased FA values in the thalamus, bulbus, globus pallidum and putamen were detected in group 1 compared to control. The FA and ADC values obtained from putamen were higher in group 3 compared to group 2. There was a negative correlation between basal ganglia and hippocampus FA values and plasma LDH values. The ADC values obtained from caudate nucleus were positively correlated with plasma D Dimer values.

CONCLUSION

ADC and FA changes may reveal hypoxia-related microstructural damage after COVID-19 infection. We speculated that the brainstem and basal ganglia can affected during the subacute period.

Meta-Analysis of the Mechanisms Underlying COVID-19 Modulation of Parkinson's Disease

Coronavirus disease-19 (COVID-19) is caused by the infection of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The virus enters host cells through receptor-mediated endocytosis of angiotensin-converting enzyme-2 (ACE2), leading to systemic inflammation, also known as a "cytokine storm", and neuroinflammation. COVID-19's upstream regulator, interferon-gamma (IFNG), is downregulated upon the infection of SARS-CoV-2, which leads to the downregulation of ACE2. The neuroinflammation signaling pathway (NISP) can lead to neurodegenerative diseases, such as Parkinson's disease (PD), which is characterized by the formation of Lewy bodies made primarily of the α-synuclein protein encoded by the synuclein alpha (SNCA) gene. We hypothesize that COVID-19 may modulate PD progression through neuroinflammation induced by cytokine storms. This study aimed to elucidate the possible mechanisms and signaling pathways involved in COVID-19-triggered pathology associated with neurodegenerative diseases like PD. This study presents the analysis of the pathways involved in the downregulation of ACE2 following SARS-CoV-2 infection and its effect on PD progression. Through QIAGEN's Ingenuity Pathway Analysis (IPA), the study identified the NISP as a top-five canonical pathway/signaling pathway and SNCA as a top-five upstream regulator. Core Analysis was also conducted on the associated molecules between COVID-19 and SNCA to construct a network connectivity map. The Molecule Activity Predictor tool was used to simulate the infection of SARS-CoV-2 by downregulating IFNG, which leads to the predicted activation of SNCA, and subsequently PD, through a dataset of intermediary molecules. Downstream effect analysis was further used to quantify the downregulation of ACE2 on SNCA activation.

COVID-19 in the nervous system: physiopathology and neurological manifestations

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a viral infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although respiratory manifestations have received greater visibility during the pandemic caused by this virus, numerous neurological complaints related to coronavirus 2 infection have been documented in several countries. These records suggest that this pathogen presents neurotropism, and it can cause different neurological conditions of varying intensity.

OBJECTIVE

To investigate the ability of coronavirus 2 to invade the central nervous system (CNS) and its neurological clinical outcomes.

METHODS

The present study consists in a comprehensive literature review of the records available in the PubMed, SciELO, and Google Scholar databases. The descriptors COVID-19, brain and physiopathology, associated with the Boolean operator AND, were used in the search. Regarding the inclusion and exclusion criteria, we selected the papers published since 2020 with the highest number of citations.

RESULTS

We selected 41 articles, most of them in English. The main clinical manifestation associated with COVID-19 patients was headache, but cases of anosmia, hyposmia, Guillain-Barré syndrome, and encephalopathies were also described with considerable frequency.

CONCLUSION

Coronavirus-2 presents neurotropism, and it can reach the CNS by hematogenous dissemination and by direct infection of the nerve endings. It causes brain injuries through several mechanisms, such as cytokine storm, microglial activation, and an increase in thrombotic factors.

Associations between underlying diseases with COVID-19 and its symptoms among adults: a cross-sectional study

Background

Specific underlying diseases were reported to be associated with severe COVID-19 outcomes, but little is known about their combined associations. The study was aimed to assess the relations of number of and specific underlying diseases to COVID-19, severe symptoms, loss of smell, and loss of taste.

Methods

A total of 28,204 adult participants in the National Health Interview Survey 2021 were included. Underlying diseases (including cardiovascular diseases, cancer, endocrine diseases, respiratory diseases, neuropsychiatric diseases, liver and kidney diseases, fatigue syndrome, and sensory impairments), the history of COVID-19, and its symptoms were self-reported by structured questionnaires. Multivariable logistic regression models were used to assess the combined relation of total number of underlying diseases to COVID-19 and its symptoms, while mutually adjusted logistic models were used to examine their independent associations.

Results

Among the 28,204 participants (mean ± standard deviation: 48.2 ± 18.5 years), each additional underlying disease was related to 33, 20, 37, and 39% higher odds of COVID-19 (odds ratio [OR]: 1.33, 95% confidence interval [CI]: 1.29-1.37), severe symptoms (OR: 1.20, 95% CI: 1.12-1.29), loss of smell (OR: 1.37, 95% CI: 1.29-1.46), and loss of taste (OR: 1.39, 95% CI: 1.31-1.49). In addition, independent associations of sensory impairments with COVID-19 (OR: 3.73, 95% CI: 3.44-4.05), severe symptoms (OR: 1.37, 95% CI: 1.13-1.67), loss of smell (OR: 8.17, 95% CI: 6.86-9.76), and loss of taste (OR: 6.13, 95% CI: 5.19-7.25), cardiovascular diseases with COVID-19 (OR: 1.13, 95% CI: 1.03-1.24), neuropsychiatric diseases with severe symptoms (OR: 1.41, 95% CI: 1.15-1.74), and endocrine diseases with loss of taste (OR: 1.28, 95% CI: 1.05-1.56) were observed.

Conclusion

A larger number of underlying diseases were related to higher odds of COVID-19, severe symptoms, loss of smell, and loss of taste in a dose-response manner. Specific underlying diseases might be individually associated with COVID-19 and its symptoms.

Consequences and Perception of the COVID-19 Pandemic on Patients and Caregivers in an Austrian Memory Clinic Population One Year After Pandemic Onset

BACKGROUND

The COVID-19 pandemic was associated with high mortality and negative consequences for patients with Alzheimer's disease or dementia and their caregivers. Memory clinics play an important role in enabling early dementia diagnosis and providing support for patients and their caregivers.

OBJECTIVE

This study investigates the impact of the COVID-19 pandemic and its restrictions on patients of a memory clinic and their caregivers between March 2020 and March 2021.

METHODS

We conducted a prospective, single-center, questionnaire-based, observational study to assess consequences and perception of the COVID-19 pandemic on emotion, cognitive function, social living, areas of care, and information retrieval.

RESULTS

Results of 255 participants' (mean age 76.78, SD 8.9; 12% cognitively intact, 33% mild cognitive impairment, 55% dementia) and 203 caregivers' COVID-19 questionnaires (valid response rate 71%) could be included in the study. Participants reported a prevalence of psychological symptoms associated with the pandemic between 3-20%. Caregivers living outside compared to those living with the participant reported higher rates of new onset or worsening of neuropsychiatric symptoms in participants since pandemic onset. Patients with dementia showed the lowest use of digital communication before (15.7%) and after (17.1%) pandemic onset in the diagnostic groups.

CONCLUSION

The COVID-19 pandemic frequently led to social isolation and reduced cognitive stimulation due to restrictions in elderly persons with cognitive deficits resulting in negative effects on emotional and social levels. We hypothesize that the implementation and sensitization with digital communication in clinical routine could provide a useful tool to counteract these negative effects.

Review of therapeutic mechanisms and applications based on SARS-CoV-2 neutralizing antibodies

COVID-19 pandemic is a global public health emergency. Despite extensive research, there are still few effective treatment options available today. Neutralizing-antibody-based treatments offer a broad range of applications, including the prevention and treatment of acute infectious diseases. Hundreds of SARS-CoV-2 neutralizing antibody studies are currently underway around the world, with some already in clinical applications. The development of SARS-CoV-2 neutralizing antibody opens up a new therapeutic option for COVID-19. We intend to review our current knowledge about antibodies targeting various regions (i.e., RBD regions, non-RBD regions, host cell targets, and cross-neutralizing antibodies), as well as the current scientific evidence for neutralizing-antibody-based treatments based on convalescent plasma therapy, intravenous immunoglobulin, monoclonal antibodies, and recombinant drugs. The functional evaluation of antibodies (i.e., in vitro or in vivo assays) is also discussed. Finally, some current issues in the field of neutralizing-antibody-based therapies are highlighted.

Evaluation of ABCD2 score during the development of stroke in COVID-19 patients diagnosed with transient ischemic attack in the emergency department

BACKGROUND

The aim of the present study is to reveal the association between the risk of stroke using ABCD2 score and COVID-19 in patients who presented to our emergency department during the pandemic and were diagnosed with TIA.

METHODS

According to the recommendations of the European Stroke Association, patients with an ABCD2 score of <4 were classified as low-risk, and patients with an ABCD2 score of ≥4 were classified as high-risk. Within 90 days of the patient's admission to the emergency room, the development of stroke was tracked and recorded on the system.

RESULTS

Stroke occurred in 35.78% of the patients. Regarding COVID-19, 75.34% of stroke patients were positive for COVID-19 and 65.75% had COVID-19 compatible pneumonia on 'thoracic CT'. Regarding mortality, 16.4% of the patients who were positive for COVID-19 and developed a stroke died. The presence of COVID-19 compatible pneumonia on thorax CT, PCR test result and ABCD2 score were determined as independent risk factors for the development of stroke. According to the PCR test results, the probability of having a stroke decreases 0.283 times in patients who are negative for COVID-19. According to the PCR test results, the probability of having a stroke increased 2.7 times in COVID-19 positive patients.

CONCLUSIONS

Adding the presence of COVID-19 and the presence of COVID-19 pneumonia to the ABCD2 score, based on the information about the increased risk of stroke in TIA patients, improves the predictive power of the score. More studies are needed in this regard.

Neurological infection and complications of SARS-CoV-2: A review

The primary target of severe acute respiratory syndrome coronavirus 2 is the respiratory system including the nose and lungs, however, it can also damage the kidneys, cardiovascular system and gastrointestinal system. Many recent reports suggested that severe acute respiratory syndrome coronavirus 2 infections can also affect the central nervous system as well as peripheral nervous system that lead to the several neurological complications. The virus can break the blood brain barrier and enters the brain via haematological route or directly by the angiotensin-converting enzyme 2 receptors present on endothelial cells of many cerebral tissues. The neurological complications are manifested by headache, dizziness, encephalopathy, encephalitis, cerebrovascular disease, anosmia, hypogeusia, muscle damage, etc. This review article described the possible routes and mechanism of nervous system infection and the range of neurological complications of COVID-19 that may help the medical practitioners and researchers to improve the clinical treatment and reduce the mortality rate among patients with viral diseases.

An integrated strategy to identify COVID-19 causal genes and characteristics represented by LRRC37A2

Genome-wide association study (GWAS) could identify host genetic factors associated with coronavirus disease 2019 (COVID-19). The genes or functional DNA elements through which genetic factors affect COVID-19 remain uncharted. The expression quantitative trait locus (eQTL) provides a path to assess the correlation between genetic variations and gene expression. Here, we firstly annotated GWAS data to describe genetic effects, obtaining genome-wide mapped genes. Subsequently, the genetic mechanisms and characteristics of COVID-19 were investigated by an integrated strategy that included three GWAS-eQTL analysis approaches. It was found that 20 genes were significantly associated with immunity and neurological disorders, including prior and novel genes such as OAS3 and LRRC37A2. The findings were then replicated in single-cell datasets to explore the cell-specific expression of causal genes. Furthermore, associations between COVID-19 and neurological disorders were assessed as a causal relationship. Finally, the effects of causal protein-coding genes of COVID-19 were discussed using cell experiments. The results revealed some novel COVID-19-related genes to emphasize disease characteristics, offering a broader insight into the genetic architecture underlying the pathophysiology of COVID-19.

Moderate Severity SARS-CoV-2 (COVID-19) Affects Ocular Vergence Indices: Eye Tracking-Based Study

OBJECTIVE

Since the start of the SARS-CoV-2 (COVID-19) pandemic, it has become clear that the brain is one of the main targets for acute and chronic damage. Although neurodegenerative changes have yet to be investigated, there is already a large body of data on damage to its fiber tracts. A mobile eye tracker is possibly one of the best tools to study such damage in a COVID hospital setting. At the same time, the available data indicate that eye tracking parameters, even in healthy volunteers, demonstrate a distinct gender-specific difference.The aim of the work is to evaluate functional and structural impairments of the fiber tracts and to find possible gender-specific dynamics of eye tracking indicators in the acute period of COVID-19 pneumonia (Delta variant) of moderate severity.

MATERIALS AND METHODS

A single-center non-randomized retrospective study included 84 patients in the acute period of moderate severity SARS-CoV-2 (COVID-19) pneumonia (Delta variant) (Group 1). The mean time from admission was 1.4 ± 1.2 days. M:41, F:43. According to thoracic CT, the lung involvement ranged from CT 1 to CT 2. SpO2 ranged from 95% to 99%. The mean age was 35.5 ± 14.8 years (from 18 to 60). The control group (Group 2) included 158 healthy volunteers without pathology of the vision organs and central nervous system.The eye vergence index (VRx) was determined using eye tracking as a motion correlation coefficient between the angular velocities of the left and right eyeballs and was a measure of the conjugation of horizontal and vertical eye movements.The mobile complex Eye Tracker Low-Speed 20 (BVG LLC, the Netherlands) was used. Eye tracking parameters were assessed by vertical and horizontal eye vergence (VVRx and HVRx).Statistical analysis was done using the methods of parametric and non-parametric statistics.

RESULTS

Moderate COVID-19 pneumonia resulted in a significant decrease in both VVRx and HVRx compared to controls (0.763 ± 0.127 and 0.856 ± 0.043; p < 0.000001; 0.729 ± 0.018 and 0.776 ± 0.023 p < 0.000001, respectively). VVRx values were significantly higher in men (0.775 ± 0.046 and 0.747 ± 0.091, p = 0.019, respectively), while ХVRx values were significantly higher in women (0.665 ± 0.018 and 0.728 ± 0.024, p < 0.0000001, respectively).

CONCLUSIONS

SARS-CoV-2 (COVID-19) of moderate severity is accompanied by a significant deterioration in eye tracking performance proving functional and structural impairments (p < 0.05). VVRx was significantly higher in men, and HVRx was substantially greater in women reflecting gender-specific differences.

The role of Substance P in the defense line of the respiratory tract and neurological manifestations post COVID-19 infection

Substance P (SP) has been a great interest for scientists due to its unique properties and involvement in various physiological and pathological phenomenon. It took almost a century for the current understanding of this peptide so far. Its role in brain and gut were initially discussed and later on it was widely studied and observed in cardiovascular system, asthma, traumatic brain injury, immune response, vasodilation, behavior, inflammation, arthritis, cancer, airway hyper responsiveness and respiratory disorders. Involvement of SP in sudden perinatal death and COVID-19 has also been discussed which shed light on its vital role in respiratory rhythm regulation and initiation of cytokine storming in COVID-19. This article will provide a comprehensive overview of the researches done to understand the basic functions and involvement of SP in different processes of cell and its association with various diseases. This article describes the historical and scientific journey of SP from its discovery until today, including its future perspectives.

Effect of inactivated COVID-19 vaccines on seizure frequency in patients with epilepsy: A multicenter, prospective study

Objectives

Several COVID-19 vaccines list "uncontrolled epilepsy" as a contraindication for vaccination. This consequently restricts vaccination against COVID-19 in patients with epilepsy (PWE). However, there is no strong evidence that COVID-19 vaccination can exacerbate conditions in PWE. This study aims to determine the impact of COVID-19 vaccination on PWE.

Methods

PWE were prospectively recruited from 25 epilepsy centers. We recorded the seizure frequency at three time periods (one month before the first vaccination and one month after the first and second vaccinations). A generalized linear mixed-effects model (GLMM) was used for analysis, and the adjusted incidence rate ratio (AIRR) with 95% CI was presented and interpreted accordingly.

Results

Overall, 859 PWE were included in the analysis. Thirty-one (3.6%) and 35 (4.1%) patients were found to have increased seizure frequency after the two doses, respectively. Age had an interaction with time. The seizure frequency in adults decreased by 81% after the first dose (AIRR=0.19, 95% CI:0.11-0.34) and 85% after the second dose (AIRR=0.16, 95% CI:0.08-0.30). In juveniles (<18), it was 25% (AIRR=0.75, 95% CI:0.42-1.34) and 51% (AIRR=0.49, 95% CI:0.25-0.95), respectively. Interval between the last seizure before vaccination and the first dose of vaccination (ILSFV) had a significant effect on seizure frequency after vaccination. Seizure frequency in PWE with hereditary epilepsy after vaccination was significantly higher than that in PWE with unknown etiology (AIRR=1.95, 95% CI: 1.17-3.24). Two hundred and seventeen (25.3%) patients experienced non-epileptic but not serious adverse reactions.

Discussion

The inactivated COVID-19 vaccine does not significantly increase seizure frequency in PWE. The limitations of vaccination in PWE should focus on aspects other than control status. Juvenile PWE should be of greater concern after vaccination because they have lower safety. Finally, PWE should not reduce the dosage of anti-seizure medication during the peri-vaccination period.

The Adverse Outcome Pathway Framework Applied to Neurological Symptoms of COVID-19

Several reports have shown that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has the potential to also be neurotropic. However, the mechanisms by which SARS-CoV-2 induces neurologic injury, including neurological and/or psychological symptoms, remain unclear. In this review, the available knowledge on the neurobiological mechanisms underlying COVID-19 was organized using the AOP framework. Four AOPs leading to neurological adverse outcomes (AO), anosmia, encephalitis, stroke, and seizure, were developed. Biological key events (KEs) identified to induce these AOs included binding to ACE2, blood–brain barrier (BBB) disruption, hypoxia, neuroinflammation, and oxidative stress. The modularity of AOPs allows the construction of AOP networks to visualize core pathways and recognize neuroinflammation and BBB disruption as shared mechanisms. Furthermore, the impact on the neurological AOPs of COVID-19 by modulating and multiscale factors such as age, psychological stress, nutrition, poverty, and food insecurity was discussed. Organizing the existing knowledge along an AOP framework can represent a valuable tool to understand disease mechanisms and identify data gaps and potentially contribute to treatment, and prevention. This AOP-aligned approach also facilitates synergy between experts from different backgrounds, while the fast-evolving and disruptive nature of COVID-19 emphasizes the need for interdisciplinarity and cross-community research.

Early SARS-CoV-2-associated acute transverse myelitis: A case for neurotropism?

There are increasing reports of immune-mediated and para-infectious syndromes beyond the well-known respiratory manifestations of severe-acute-respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, the spectrum of severe neurological sequelae of SARS-CoV-2 remains undefined. We present the case of a 66-year-old female with rapidly progressive lower limb neurology 3 days post SARS-CoV-2 infection. Clinical and radiological findings were in keeping with transverse myelitis and treatment success was achieved with methylprednisolone and remdesivir. This report will discuss the associations between SARS-CoV-2 and acute transverse myelitis. We believe this is one of few described cases of early SARS-CoV-2-associated transverse myelitis secondary to neurotropism and the first successfully treated with the inclusion of remdesivir in the therapeutic regimen.

Role of Demyelination in the Persistence of Neurological and Mental Impairments after COVID-19

Long-term neurological and mental complications of COVID-19, the so-called post-COVID syndrome or long COVID, affect the quality of life. The most persistent manifestations of long COVID include fatigue, anosmia/hyposmia, insomnia, depression/anxiety, and memory/attention deficits. The physiological basis of neurological and psychiatric disorders is still poorly understood. This review summarizes the current knowledge of neurological sequelae in post-COVID patients and discusses brain demyelination as a possible mechanism of these complications with a focus on neuroimaging findings. Numerous reviews, experimental and theoretical studies consider brain demyelination as one of the mechanisms of the central neural system impairment. Several factors might cause demyelination, such as inflammation, direct effect of the virus on oligodendrocytes, and cerebrovascular disorders, inducing myelin damage. There is a contradiction between the solid fundamental basis underlying demyelination as the mechanism of the neurological injuries and relatively little published clinical evidence related to demyelination in COVID-19 patients. The reason for this probably lies in the fact that most clinical studies used conventional MRI techniques, which can detect only large, clearly visible demyelinating lesions. A very limited number of studies use specific methods for myelin quantification detected changes in the white matter tracts 3 and 10 months after the acute phase of COVID-19. Future research applying quantitative MRI assessment of myelin in combination with neurological and psychological studies will help in understanding the mechanisms of post-COVID complications associated with demyelination.

COVID-19 neuropsychiatric repercussions: Current evidence on the subject

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has affected the entire world, causing the coronavirus disease 2019 (COVID-19) pandemic since it was first discovered in Wuhan, China in December 2019. Among the clinical presentation of the disease, in addition to fever, fatigue, cough, dyspnea, diarrhea, nausea, vomiting, and abdominal pain, infected patients may also experience neurological and psychiatric repercussions during the course of the disease and as a post-COVID-19 sequelae. Thus, headache, dizziness, olfactory and gustatory dysfunction, cerebrovascular disorders, neuromuscular abnormalities, anxiety, depression, and post-traumatic stress disorder can occur both from the infection itself and from social distancing and quarantine. According to current evidence about this infection, the virus has the ability to infect the central nervous system (CNS) via angiotensin-converting enzyme 2 (ACE2) receptors on host cells. Several studies have shown the presence of ACE2 in nerve cells and nasal mucosa, as well as transmembrane serine protease 2, key points for interaction with the viral Spike glycoprotein and entry into the CNS, being olfactory tract and blood-brain barrier, through hematogenous dissemination, potential pathways. Thus, the presence of SARS-CoV-2 in the CNS supports the development of neuropsychiatric symptoms. The management of these manifestations seems more complex, given that the dense parenchyma and impermeability of brain tissue, despite protecting the brain from the infectious process, may hinder virus elimination. Still, some alternatives used in non-COVID-19 situations may lead to worse prognosis of acute respiratory syndrome, requiring caution. Therefore, the aim of this review is to bring more current points related to this infection in the CNS, as well as the repercussions of the isolation involved by the pandemic and to present perspectives on interventions in this scenario.

Neurological Complications of COVID-19: A Review of the Literature

Coronavirus disease 2019 (COVID-19) has caused the most unprecedented health crisis since the 1918 H1N1 pandemic. Whilst COVID-19 is traditionally considered to be a respiratory disease, it is important to understand that this virus has the potential to disseminate throughout the body causing multi-organ failure. Both peripheral and central neurological systems have been shown to be greatly affected. This review aims to look at the available literature published on COVID-19 and summarize the main neurological complications seen so far.

Pathological Features and Neuroinflammatory Mechanisms of SARS-CoV-2 in the Brain and Potential Therapeutic Approaches

The number of deaths has been increased due to COVID-19 infections and uncertain neurological complications associated with the central nervous system. Post-infections and neurological manifestations in neuronal tissues caused by COVID-19 are still unknown and there is a need to explore how brainstorming promoted congenital impairment, dementia, and Alzheimer's disease. SARS-CoV-2 neuro-invasion studies in vivo are still rare, despite the fact that other beta-coronaviruses have shown similar properties. Neural (olfactory or vagal) and hematogenous (crossing the blood-brain barrier) pathways have been hypothesized in light of new evidence showing the existence of SARS-CoV-2 host cell entry receptors into the specific components of human nerve and vascular tissue. Spike proteins are the primary key and structural component of the COVID-19 that promotes the infection into brain cells. Neurological manifestations and serious neurodegeneration occur through the binding of spike proteins to ACE2 receptor. The emerging evidence reported that, due to the high rate in the immediate wake of viral infection, the olfactory bulb, thalamus, and brain stem are intensely infected through a trans-synaptic transfer of the virus. It also instructs the release of chemokines, cytokines, and inflammatory signals immensely to the blood-brain barrier and infects the astrocytes, which causes neuroinflammation and neuron death; and this induction of excessive inflammation and immune response developed in more neurodegeneration complications. The present review revealed the pathophysiological effects, molecular, and cellular mechanisms of possible entry routes into the brain, pathogenicity of autoantibodies and emerging immunotherapies against COVID-19.

MicroRNA Networks in Cognition and Dementia

The change from viewing noncoding RNA as “junk” in the genome to seeing it as a critical epigenetic regulator in almost every human condition or disease has forced a paradigm shift in biomedical and clinical research. Small and long noncoding RNA transcripts are now routinely evaluated as putative diagnostic or therapeutic agents. A prominent role for noncoding microRNAs in the central nervous system has uncovered promising new clinical candidates for dementia-related disorders, treatments for which currently remain elusive even as the percentage of diagnosed patients increases significantly. Cognitive decline is a core neurodegenerative process in Alzheimer’s Disease, Frontotemporal Dementia, Lewy body dementia, vascular dementia, Huntington’s Disease, Creutzfeldt–Jakob disease, and a significant portion of Parkinson’s Disease patients. This review will discuss the microRNA-associated networks which influence these pathologies, including inflammatory and viral-mediated pathways (such as the novel SARS-CoV-2 virus implicated in COVID-19), and their current status in clinical trials.

Deleterious effects of nervous system in the offspring following maternal SARS-CoV-2 infection during the COVID-19 pandemic

During the Coronavirus disease 2019 (COVID-19) pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is universally susceptible to all types of populations. In addition to the elderly and children becoming the groups of great concern, pregnant women carrying new lives need to be even more alert to SARS-CoV-2 infection. Studies have shown that pregnant women infected with SARS-CoV-2 can lead to brain damage and post-birth psychiatric disorders in offspring. It has been widely recognized that SARS-CoV-2 can affect the development of the fetal nervous system directly or indirectly. Pregnant women are recommended to mitigate the effects of COVID-19 on the fetus through vaccination, nutritional supplements, and psychological support. This review summarizes the possible mechanisms of the nervous system effects of SARS-CoV-2 infection on their offspring during the pregnancy and analyzes the available prophylactic and treatment strategies to improve the prognosis of fetal-related neuropsychiatric diseases after birth.

Neurological and Psychiatric Symptoms of COVID-19: A Narrative Review

Recently dubbed Long COVID or Long-Haul COVID, those recovering from the initial COVID-19 infection may maintain clinical signs for longer than two or more weeks following the initial onset of the infection. The virus can gain entry into the CNS through axonal transport mediated through the olfactory nerve or hematogenous spread and can also cross the blood–brain barrier to access the temporal lobe and the brainstem. The neurologic and neuropsychiatric symptoms associated with COVID-19 patients are becoming a highly studied area due to the increased frequency of reported cases. Multiple hospital case series and observational studies have found a headache to be a common symptom among patients who are symptomatic with the SARS-CoV-2 virus. The headache described by many of these patients is similar to new daily persistent headache (NDPH). NDPH potentially develops in response to pro-inflammatory cytokines during a persistent systemic or CNS inflammation, mostly due to the initial infection. The treatments investigated were high-dose steroids, tetracycline derivatives, onabotulinum toxin type A, and long-term multidrug regimens. Among the identified symptoms of post-COVID-19 viral illness, fatigue appears to be the most ubiquitous. High-dose vitamin C is currently a suggested therapy proposed for its antioxidant, anti-inflammatory, and immunomodulatory properties. The mental health consequences of this diagnosis are being identified among large portions of COVID-19 survivors. Among these consequences, cases of major depressive disorder (MDD) and anxiety are being reported and closely examined. The aim of this narrative review is to highlight the neurological and psychiatric symptoms that have been associated with Long-Haul COVID and their possible treatments.

Tapia's Syndrome: keep it in mind!

INTRODUCTION

The aim of this study was to revise the etiologic features about Tapia's Syndrome (TS), a condition to particularly consider in the era of the COVID-19 pandemic.

EVIDENCE ACQUISITION

A systematic review was performed according to the PRISMA criteria. The Medline and Embase databases were searched from January 1, 1990, to December 31, 2020. Initially the search yielded 399 manuscripts, which were reduced to 50, upon the application of inclusion criteria.

EVIDENCE SYNTHESIS

A total of 65 patients were included in the present review. Mean age was 44±17.5 (DS) years (15-95); M:F ratio was 2.3:1. TS involved mainly the left side (3:2) and was rarely bilateral. Only 2 TS reported cases were due to central causes. Peripheral causes were mainly due to postintubation edema (77%), extrinsic compression (15%), vascular disease (3%), other/not defined (5%).

CONCLUSIONS

TS is a rare syndrome that has been related to a combined cranial nerve palsy; while TS due to central causes is very rare, it is mainly related to peripheral causes. A particular attention to TS should be given during the SARS-CoV-2 pandemic, either since the correlation between Tapia's syndrome, airway management and anesthetic procedures, since the possible implication of the viral infection itself.

Mendelian randomization study on the causal effects of COVID-19 on childhood intelligence

Although individuals with coronavirus disease 2019 (COVID‐19) are known to be at increased risk for other conditions resulting from pathogenic changes (including metaplastic or anaplastic) in the lungs and other organs and organ systems, it is still unknown whether COVID‐19 affects childhood intelligence. The present two‐sample Mendelian randomization study aims to identify the genetic causal link between COVID‐19 and childhood intelligence. Four COVID‐19 genetic instrumental variants (IVs) were chosen from the largest genome‐wide association studies (GWAS) for COVID‐19 (hospitalized vs. population) (6406 cases and 902 088 controls of European ancestry). The largest childhood intelligence GWAS (n = 12 441 individuals of European ancestry) was used to evaluate the effect of the identified COVID‐19‐associated genetic IVs on childhood intelligence. We found that as the genetic susceptibility to COVID‐19 increased, childhood intelligence followed a decreasing trend, according to mr_egger (β = −0.156; p = 0.601; odds ratio [OR] = 0.856; 95% confidence interval [CI]: 0.522–1.405), simple mode (β = −0.126; p = 0.240; OR = 0.882; 95% CI: 0.745–1.044), and weighted mode (β = −0.121; p = 0.226; OR = 0.886; 95% CI: 0.758–1.036) analyses. This trend was further demonstrated by the weighted median (β = −0.134; p = 0.031; OR = 0.875; 95% CI: 0.774–0.988) and the inverse variance weighted (β = −0.152; p = 0.004; OR = 0.859; 95% CI: 0.776–0.952). Our analysis suggests a causal link between genetically increased COVID‐19 and decreased childhood intelligence. Thus, COVID‐19 may be a risk factor for declines in childhood intelligence.

Loneliness as risk factor for Alzheimer´s disease

There is considerable empirical evidence that unequivocally points to loneliness as a modifiable risk factor for the development of Alzheimer's disease and other related dementias. With the emergence of the COVID-19 pandemic and the resulting lockdown and social distancing, there has been renewed interest in studying this topic. The present review examines the links between loneliness and Alzheimer's disease, with particular emphasis on the mechanisms common to both conditions.

Eye Movement Alterations in Post-COVID-19 Condition: A Proof-of-Concept Study

There is much evidence pointing out eye movement alterations in several neurological diseases. To the best of our knowledge, this is the first video-oculography study describing potential alterations of eye movements in the post-COVID-19 condition. Visually guided saccades, memory-guided saccades, and antisaccades in horizontal axis were measured. In all visual tests, the stimulus was deployed with a gap condition. The duration of the test was between 5 and 7 min per participant. A group of n=9 patients with the post-COVID-19 condition was included in this study. Values were compared with a group (n=9) of healthy volunteers whom the SARS-CoV-2 virus had not infected. Features such as centripetal and centrifugal latencies, success rates in memory saccades, antisaccades, and blinks were computed. We found that patients with the post-COVID-19 condition had eye movement alterations mainly in centripetal latency in visually guided saccades, the success rate in memory-guided saccade test, latency in antisaccades, and its standard deviation, which suggests the involvement of frontoparietal networks. Further work is required to understand these eye movements' alterations and their functional consequences.

Mental depression: Relation to different disease status, newer treatments and its association with COVID-19 pandemic (Review)

The present study aimed to review major depression, including its types, epidemiology, association with different diseases status and treatments, as well as its correlation with the current COVID-19 pandemic. Mental depression is a common disorder that affects most individuals at one time or another. During depression, there are changes in mood and behavior, accompanied by feelings of defeat, hopelessness, or even suicidal thoughts. Depression has a direct or indirect relation with a number of other diseases including Alzheimer's disease, stroke, epilepsy, diabetes, cardiovascular disease and cancer. In addition, antidepressant drugs have several side effects including sedation, increased weight, indigestion, sexual dysfunction, or a decrease in blood pressure. Stopping medication may cause a relapse of the symptoms of depression and pose a risk of attempted suicide. The pandemic of COVID-19 has affected the mental health of individuals, including patients, individuals contacting patients and medical staff with a number of mental disorders that may adversely affect the immune ability of their bodies. Some of the drugs currently included in the protocols for treating COVID-19 may negatively affect the mental health of patients. Evidence accumulated over the years indicates that serotonin (5HT) deficiencies and norepinephrine (NE) in the brain can lead to mental depression. Drugs that increase levels of NE and 5HT are commonly used in the treatment of depression. The common reason for mood disorders, including mania and bipolar disease are not clearly understood. It is assumed that hyperactivity in specific parts of the brain and excessive activity of neurotransmitters may be involved. Early diagnosis and developing new treatment strategies are essential for the prevention of the severe consequences of depression. In addition, extensive research should be directed towards the investigation of the mental health disturbances occurring during and/or after COVID-19 infection. This may lead to the incorporation of a suitable antidepressant into the current treatment protocols.

Is there a common pathophysiological mechanism between COVID-19 and depression?

COVID-19 is a disease caused by SARS-CoV-2 and was initially considered to cause serious damage to the respiratory system. Over time, it has been found to affect other organs due to its ability to bind to the ACE2 receptor (type 2 angiotensin-converting enzyme), which can be found in various tissues, including the central nervous system. In addition, a large formation of pro-inflammatory cytokines responsible for various lesions was observed during the evolution of this disease. Our objective was to demonstrate the molecular mechanisms involved in the infection that may demonstrate the relationship between COVID-19 and the development of depressive conditions. Based on the main medical databases (LiLacs, SciELO, Bireme, Scopus, EBSCO, and PubMed) and using the terms 'coronavirus infections' AND 'Inflammation' AND 'depression' AND 'cytokines', we conducted an integrative review of articles published in 2020. Considering this stage of Covid-19 and the inflammatory component of depression, this review showed a relationship between these two conditions based on common pathophysiological mechanisms indicating possible depressive disorders in surviving patients, especially in the most severe cases. The role of inflammatory cytokines and the presence of ACE-2 receptors on the cell surface appear to be the common pathophysiological mechanism between COVID-19 and depression.

N-acylethanolamine regulation of TLR3-induced hyperthermia and neuroinflammatory gene expression: A role for PPARα

Increasing evidence suggests that SARS-CoV-2, the virus responsible for the COVID-19 pandemic, is associated with increased risk of developing neurological or psychiatric conditions such as depression, anxiety or dementia. While the precise mechanism underlying this association is unknown, aberrant activation of toll-like receptor (TLR)3, a viral recognizing pattern recognition receptor, may play a key role. Synthetic cannabinoids and enhancing cannabinoid tone via inhibition of fatty acid amide hydrolase (FAAH) has been demonstrated to modulate TLR3-induced neuroimmune responses and associated sickness behaviour. However, the role of individual FAAH substrates, and the receptor mechanisms mediating these effects, are unknown. The present study examined the effects of intracerebral or systemic administration of the FAAH substrates N-oleoylethanolamide (OEA), N-palmitoylethanolamide (PEA) or the anandamide (AEA) analogue meth-AEA on hyperthermia and hypothalamic inflammatory gene expression following administration of the TLR3 agonist, and viral mimetic, poly I:C. The data demonstrate that meth-AEA does not alter TLR3-induced hyperthermia or hypothalamic inflammatory gene expression. In comparison, OEA and PEA attenuated the TLR3-induced hyperthermia, although only OEA attenuated the expression of hyperthermia-related genes (IL-1β, iNOS, COX2 and m-PGES) in the hypothalamus. OEA, but not PEA, attenuated TLR3-induced increases in the expression of all IRF- and NFκB-related genes examined in the hypothalamus, but not in the spleen. Antagonism of PPARα prevented the OEA-induced attenuation of IRF- and NFκB-related genes in the hypothalamus following TLR3 activation but did not significantly alter temperature. PPARα agonism did not alter TLR3-induced hyperthermia or hypothalamic inflammatory gene expression. These data indicate that OEA may be the primary FAAH substrate that modulates TLR3-induced neuroinflammation and hyperthermia, effects partially mediated by PPARα.

The co-circulation of two infectious diseases and the impact of vaccination against one of them

An epidemiological model based on probabilistic cellular automaton is proposed to investigate the dynamics of two co-circulating infections. In the model, one of these two diseases compromises the immune response to future infections; however, there is vaccine against this immunosuppressive disease. The goal is to evaluate the impact of the vaccination coverage on the prevalence and on the cumulative deaths associated with both contagious diseases. The performed numerical simulations highlight the importance of vaccination on decreasing morbidity and mortality. The results are discussed from a public health standpoint, by taking into account outbreaks of measles and COVID-19.

Association of CNS demyelination and COVID-19 infection: an updated systematic review

Background

Since the declaration of COVID-19 pandemic, several case reports of demyelination of both peripheral and central nervous systems have been published. The association between CNS demyelination and viral infection has long been documented, and this link was recently reported following SARS-CoV-2 infection as well.

Objectives

In this systematic review, we aim to investigate the existing literature on CNS demyelination associated with SARS-CoV-2, and the proposed pathophysiological mechanisms.

Methods

We conducted a systematic review of articles in PubMed, SCOPUS, EMBASE, Cochrane, Google Scholar and Ovid databases, from 1 January 2020 until June 15, 2021. The following keywords were used: “COVID-19”, “SARS-CoV-2”, “demyelination”, “demyelinating disease”, “multiple sclerosis”, “neuromyelitis optica”, and “transverse myelitis”.

Results

A total of 60 articles were included in the final analysis of this systematic review and included 102 patients: 52 (51%) men and 50 (49%) women, with a median age of 46.5 years. The demyelination mimicked a variety of conditions with a picture of encephalitis/encephalomyelitis being the most common. At the same time other patterns were less frequently reported such as MS, NMOSD and even MOGAD. Longitudinally extensive transverse myelitis (LETM) was the most frequently reported pattern of spinal cord involvement.

Conclusion

A growing body of literature has shown an association between SARS‐CoV‐2 infection and the development of different types of CNS demyelination. Although causality cannot readily be inferred, this review may suggest a probable causal relationship, through a para-infectious or post-infectious immune-mediated etiology in COVID-19 patients. This relationship needs to be clarified in future research.

Molecular Mechanisms of Palmitic Acid Augmentation in COVID-19 Pathologies

The coronavirus disease 2019 (COVID-19) pandemic has claimed over 2.7 million lives globally. Obesity has been associated with increased severity and mortality of COVID-19. However, the molecular mechanisms by which obesity exacerbates COVID-19 pathologies are not well-defined. The levels of free fatty acids (FFAs) are elevated in obese subjects. This study was therefore designed to examine how excess levels of different FFAs may affect the progression of COVID-19. Biological molecules associated with palmitic acid (PA) and COVID-19 were retrieved from QIAGEN Knowledge Base, and Ingenuity Pathway Analysis tools were used to analyze these datasets and explore the potential pathways affected by different FFAs. Our study found that one of the top 10 canonical pathways affected by PA was the coronavirus pathogenesis pathway, mediated by key inflammatory mediators, including PTGS2; cytokines, including IL1β and IL6; chemokines, including CCL2 and CCL5; transcription factors, including NFκB; translation regulators, including EEF1A1; and apoptotic mediators, including BAX. In contrast, n-3 fatty acids may attenuate PA's activation of the coronavirus pathogenesis pathway by inhibiting the activity of such mediators as IL1β, CCL2, PTGS2, and BAX. Furthermore, PA may modulate the expression of ACE2, the main cell surface receptor for the SARS-CoV-2 spike protein.

Can COVID-19 accelerate neurodegeneration?

COVID-19 may accelerate neurodegeneration in patients with neurodegenerative disease.

Drug repurposing of selective serotonin reuptake inhibitors: Could these drugs help fight COVID-19 and save lives?

The current 2019 novel coronavirus disease (COVID-19), an emerging infectious disease, is undoubtedly the most challenging pandemic in the 21st century. A total of 92,977,768 confirmed cases of COVID-19 and 1,991,289 deaths were reported globally up to January 14, 2021. COVID-19 also affects people's mental health and quality of life. At present, there is no effective therapeutic strategy for the management of this disease. Therefore, in the absence of a specific vaccine or curative treatment, it is an urgent need to identify safe, effective and globally available drugs for reducing COVID-19 morbidity and fatalities. In this review, we focus on selective serotonin reuptake inhibitors (SSRIs: a class of antidepressant drugs with widespread availability and an optimal tolerability profile) that can potentially be repurposed for COVID-19 and are currently being tested in clinical trials. We also summarize the existing literature on what is known about the link between serotonin (5-HT) and the immune system. From the evidence reviewed here, we propose fluoxetine as an adjuvant therapeutic agent for COVID-19 based on its known immunomodulatory, anti-inflammatory and antiviral properties. Fluoxetine may potentially reduce pro-inflammatory chemokine/cytokines levels (such as CCL-2, IL-6, and TNF-α) in COVID-19 patients. Furthermore, fluoxetine may help to attenuate neurological complications of COVID-19.

Biosensing surfaces and therapeutic biomaterials for the central nervous system in COVID-19

COVID-19 can affect the central nervous system (CNS) indirectly by inflammatory mechanisms and even directly enter the CNS. Thereby, COVID-19 can evoke a range of neurosensory conditions belonging to infectious, inflammatory, demyelinating, and degenerative classes. A broad range of non-specific options, including anti-viral agents and anti-inflammatory protocols, is available with varying therapeutic. Due to the high mortality and morbidity in COVID-19-related brain damage, some changes to these general protocols, however, are necessary for ensuring the delivery of therapeutic(s) to the specific components of the CNS to meet their specific requirements. The biomaterials approach permits crossing the blood-brain barrier (BBB) and drug delivery in a more accurate and sustained manner. Beyond the BBB, drugs can protect neural cells, stimulate endogenous stem cells, and induce plasticity more effectively. Biomaterials for cell delivery exist, providing an efficient tool to improve cell retention, survival, differentiation, and integration. This paper will review the potentials of the biomaterials approach for the damaged CNS in COVID-19. It mainly includes biomaterials for promoting synaptic plasticity and modulation of inflammation in the post-stroke brain, extracellular vesicles, exosomes, and conductive biomaterials to facilitate neural regeneration, and artificial nerve conduits for treatment of neuropathies. Also, biosensing surfaces applicable to the first sensory interface between the host and the virus that encourage the generation of accelerated anti-viral immunity theoretically offer hope in solving COVID-19.

Does COVID-19 contribute to development of neurological disease?

BACKGROUND

Although coronavirus disease 2019 (COVID-19) has been associated primarily with pneumonia, recent data show that the causative agent of COVID-19, the coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can infect a large number of vital organs beyond the lungs, such as the heart, kidneys, and the brain. Thus, there is evidence showing possible retrograde transmission of the virus from the olfactory epithelium to regions of the brain stem.

METHODS

This is a literature review article. The research design method is an evidence-based rapid review. The present discourse aim is first to scrutinize and assess the available literature on COVID-19 repercussion on the central nervous system (CNS). Standard literature and database searches were implemented, gathered relevant material, and extracted information was then assessed.

RESULTS

The angiotensin-converting enzyme 2 (ACE2) receptors being the receptor for the virus, the threat to the central nervous system is expected. Neurons and glial cells express ACE2 receptors in the CNS, and recent studies suggest that activated glial cells contribute to neuroinflammation and the devastating effects of SARS-CoV-2 infection on the CNS. The SARS-CoV-2-induced immune-mediated demyelinating disease, cerebrovascular damage, neurodegeneration, and depression are some of the neurological complications discussed here.

CONCLUSION

This review correlates present clinical manifestations of COVID-19 patients with possible neurological consequences in the future, thus preparing healthcare providers for possible future consequences of COVID-19.