Disorders of the Cholinergic System in COVID-19 Era-A Review of the Latest Research

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

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

The Risk of Exacerbation of Myasthenia Gravis After COVID-19 Omicron Infection

OBJECTIVE

The aim of this study is to ascertain whether COVID-19 Omicron infection is associated with exacerbations in these myasthenia gravis (MG) patients.

RESULT

In total, 289 MG patients (comprising 60% females, with an average age of 46 ± 15 years) were enrolled. A total of 80.9% of MG patients reported a COVID-19 infection, with the majority experiencing a benign course (88%). MG patients who experienced COVID-19 infection demonstrated a higher likelihood of MG exacerbation, compared to those without the infection (18.8% vs. 7.3%, p = 0.039). In the survival analysis, after adjusting for confounding factors, the hazard ratio (HR) for exacerbation post-infection was found to be 3.38 (95% CI 1.20-9.53, p = 0.021). Compared to the exacerbation rates observed in JTA21, an increase was noted in DTM23 among COVID-19-infected MG patients (4.4% vs. 17.2%, p < 0.001).

CONCLUSION

The COVID-19 is the risk of MG exacerbation.

Effect and mechanism of quercetin or quercetin-containing formulas against COVID-19: From bench to bedside

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the global coronavirus disease 2019 (COVID-19) pandemic since 2019. Immunopathogenesis and thromboembolic events are central to its pathogenesis. Quercetin exhibits several beneficial activities against COVID-19, including antiviral, anti-inflammatory, immunomodulatory, antioxidative, and antithrombotic effects. Although several reviews have been published, these reviews are incomplete from the viewpoint of translational medicine. The authors comprehensively evaluated the evidence of quercetin against COVID-19, both basically and clinically, to apply quercetin and/or its derivatives in the future. The authors searched the PubMed, Embase, and the Cochrane Library databases without any restrictions. The search terms included COVID-19, SARS-CoV-2, quercetin, antiviral, anti-inflammatory, immunomodulatory, thrombosis, embolism, oxidative, and microbiota. The references of relevant articles were also reviewed. All authors independently screened and reviewed the quality of each included manuscript. The Cochrane Risk of Bias Tool, version 2 (RoB 2) was used to assess the quality of the included randomized controlled trials (RCTs). All selected studies were discussed monthly. The effectiveness of quercetin against COVID-19 is not solid due to methodological flaws in the clinical trials. High-quality studies are also required for quercetin-containing traditional Chinese medicines. The low bioavailability and highly variable pharmacokinetics of quercetin hinder its clinical applications. Its positive impact on immunomodulation through reverting dysbiosis of gut microbiota still lacks robust evidence. Quercetin against COVID-19 does not have tough clinical evidence. Strategies to improve its bioavailability and/or to develop its effective derivatives are needed. Well-designed RCTs are also crucial to confirm their effectiveness in the future.

SARS-CoV-2-Related Olfactory Dysfunction: Autopsy Findings, Histopathology, and Evaluation of Viral RNA and ACE2 Expression in Olfactory Bulbs

BACKGROUND

The COVID-19 pandemic has been a health emergency with a significant impact on the world due to its high infectiousness. The disease, primarily identified in the lower respiratory tract, develops with numerous clinical symptoms affecting multiple organs and displays a clinical finding of anosmia. Several authors have investigated the pathogenetic mechanisms of the olfactory disturbances caused by SARS-CoV-2 infection, proposing different hypotheses and showing contradictory results. Since uncertainties remain about possible virus neurotropism and direct damage to the olfactory bulb, we investigated the expression of SARS-CoV-2 as well as ACE2 receptor transcripts in autoptic lung and olfactory bulb tissues, with respect to the histopathological features.

METHODS

Twenty-five COVID-19 olfactory bulbs and lung tissues were randomly collected from 200 initial autopsies performed during the COVID-19 pandemic. Routine diagnosis was based on clinical and radiological findings and were confirmed with post-mortem swabs. Real-time RT-PCR for SARS-CoV-2 and ACE2 receptor RNA was carried out on autoptic FFPE lung and olfactory bulb tissues. Histological staining was performed on tissue specimens and compared with the molecular data.

RESULTS

While real-time RT-PCR for SARS-CoV-2 was positive in 23 out of 25 lung samples, the viral RNA expression was absent in olfactory bulbs. ACE2-receptor RNA was present in all tissues examined, being highly expressed in lung samples than olfactory bulbs.

CONCLUSIONS

Our finding suggests that COVID-19 anosmia is not only due to neurotropism and the direct action of SARS-CoV-2 entering the olfactory bulb. The mechanism of SARS-CoV-2 neuropathogenesis in the olfactory bulb requires a better elucidation and further research studies to mitigate the olfactory bulb damage associated with virus action.

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

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

Long COVID as a Tauopathy: Of "Brain Fog" and "Fusogen Storms"

Long COVID, also called post-acute sequelae of SARS-CoV-2, is characterized by a multitude of lingering symptoms, including impaired cognition, that can last for many months. This symptom, often called "brain fog", affects the life quality of numerous individuals, increasing medical complications as well as healthcare expenditures. The etiopathogenesis of SARS-CoV-2-induced cognitive deficit is unclear, but the most likely cause is chronic inflammation maintained by a viral remnant thriving in select body reservoirs. These viral sanctuaries are likely comprised of fused, senescent cells, including microglia and astrocytes, that the pathogen can convert into neurotoxic phenotypes. Moreover, as the enteric nervous system contains neurons and glia, the virus likely lingers in the gastrointestinal tract as well, accounting for the intestinal symptoms of long COVID. Fusogens are proteins that can overcome the repulsive forces between cell membranes, allowing the virus to coalesce with host cells and enter the cytoplasm. In the intracellular compartment, the pathogen hijacks the actin cytoskeleton, fusing host cells with each other and engendering pathological syncytia. Cell-cell fusion enables the virus to infect the healthy neighboring cells. We surmise that syncytia formation drives cognitive impairment by facilitating the "seeding" of hyperphosphorylated Tau, documented in COVID-19. In our previous work, we hypothesized that the SARS-CoV-2 virus induces premature endothelial senescence, increasing the permeability of the intestinal and blood-brain barrier. This enables the migration of gastrointestinal tract microbes and/or their components into the host circulation, eventually reaching the brain where they may induce cognitive dysfunction. For example, translocated lipopolysaccharides or microbial DNA can induce Tau hyperphosphorylation, likely accounting for memory problems. In this perspective article, we examine the pathogenetic mechanisms and potential biomarkers of long COVID, including microbial cell-free DNA, interleukin 22, and phosphorylated Tau, as well as the beneficial effect of transcutaneous vagal nerve stimulation.

Clinical Characteristics of Myasthenia Gravis Patients with COVID-19 in Guangxi, China: A Case-Control Study

Purpose

With the adjustment of prevention strategies in December 2022, coronavirus disease 2019 (COVID-19) became widely prevalent in China. This study is aimed to describe the clinical characteristics of myasthenia gravis (MG) patients with COVID-19 and identify risk factors of exacerbation in MG patients with COVID-19 in Guangxi.

Patients and Methods

A total of 489 MG patients and 587 control subjects in Guangxi during the COVID-19 pandemic were enrolled in this case-control study. After contacting the participants, the clinical data of MG patients and the control group were analyzed. The clinical characteristics of MG patients with COVID-19 were described. Multivariable logistic regression analysis was used for discovering independent risk factors of MG exacerbation in the patients with MG and COVID-19.

Results

A total of 311 (75.30%) MG patients and 428 (72.91%) control subjects were infected with COVID-19, and 64.31% of MG patients with COVID-19 were women. The median age at the time of interview was 41 (IQR: 28, 54) years old, and median onset age was 36 (IQR: 24, 51), both of which were lower than those in MG patients without COVID-19. MG duration was 24 (IQR: 9, 72) months. About 44.69% of patients were generalized MG (GMG). About 11.90% of MG patients with COVID-19 showed severe COVID-19 symptoms and the duration of symptomatic COVID-19 was 9.57 ± 6.79 days, higher than those in the control group. About 35.69% MG patients with immunosuppressive drugs were infected with COVID-19, which is higher than those in the non-infected MG patients (21.57%). A total of 120 (38.59%) MG patients with COVID-19 had comorbidities. About 21 (20.19%) of the 104 MG patients without vaccination showed severe COVID-19 symptoms. Multivariable logistic regression analysis showed that baseline MG activities of daily living profile (MG-ADL, OR 1.280, 95% CI: 1.010-1.621, p = 0.041), duration of COVID-19 (OR 1.158, 95% CI: 1.100-1.220, p < 0.001), GMG (OR 2.331, 95% CI: 1.228, 4.426, p = 0.010), and lack of COVID vaccination (OR 2.075, 95% CI: 1.152, 3.738, p = 0.015) were independent factors of exacerbation in MG patients with COVID-19.

Conclusion

MG patients with immunosuppressive drugs, younger onset, longer MG duration, or comorbidities are more susceptible to COVID-19. The baseline MG-ADL, duration of symptomatic COVID-19, GMG, and lack of COVID-19 vaccination are independent risk factors of exacerbation in MG patients with COVID-19.

Cholinergic dysfunction in COVID-19: frantic search and hoping for the best

A novel coronavirus known as severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a potential cause of acute respiratory infection called coronavirus disease 2019 (COVID-19). The binding of SARS-CoV-2 with angiotensin-converting enzyme 2 (ACE2) induces a series of inflammatory cellular events with cytopathic effects leading to cell injury and hyperinflammation. Severe SARS-CoV-2 infection may lead to dysautonomia and sympathetic storm due to dysfunction of the autonomic nervous system (ANS). Therefore, this review aimed to elucidate the critical role of the cholinergic system (CS) in SARS-CoV-2 infection. The CS forms a multi-faceted network performing diverse functions in the body due to its distribution in the neuronal and non-neuronal cells. Acetylcholine (ACh) acts on two main types of receptors which are nicotinic receptors (NRs) and muscarinic receptors (MRs). NRs induce T cell anergy with impairment of antigen-mediated signal transduction. Nicotine through activation of T cell NRs inhibits the expression and release of the pro-inflammatory cytokines. NRs play important anti-inflammatory effects while MRs promote inflammation by inducing the release of pro-inflammatory cytokines. SARS-CoV-2 infection can affect the morphological and functional stability of CS through the disruption of cholinergic receptors. SARS-CoV-2 spike protein is similar to neurotoxins, which can bind to nicotinic acetylcholine receptors (nAChR) in the ANS and brain. Therefore, cholinergic receptors mainly nAChR and related cholinergic agonists may affect the pathogenesis of SARS-CoV-2 infection. Cholinergic dysfunction in COVID-19 is due to dysregulation of nAChR by SARS-CoV-2 promoting the central sympathetic drive with the development of the sympathetic storm. As well, nAChR activators through interaction with diverse signaling pathways can reduce the risk of inflammatory disorders in COVID-19. In addition, nAChR activators may mitigate endothelial dysfunction (ED), oxidative stress (OS), and associated coagulopathy in COVID-19. Similarly, nAChR activators may improve OS, inflammatory changes, and cytokine storm in COVID-19. Therefore, nAChR activators like varenicline in virtue of its anti-inflammatory and anti-oxidant effects with direct anti-SARS-CoV-2 effect could be effective in the management of COVID-19.

Altered microRNA Transcriptome in Cultured Human Airway Cells upon Infection with SARS-CoV-2

Numerous proteomic and transcriptomic studies have been carried out to better understand the current multi-variant SARS-CoV-2 virus mechanisms of action and effects. However, they are mostly centered on mRNAs and proteins. The effect of the virus on human post-transcriptional regulatory agents such as microRNAs (miRNAs), which are involved in the regulation of 60% of human gene activity, remains poorly explored. Similar to research we have previously undertaken with other viruses such as Ebola and HIV, in this study we investigated the miRNA profile of lung epithelial cells following infection with SARS-CoV-2. At the 24 and 72 h post-infection time points, SARS-CoV-2 did not drastically alter the miRNome. About 90% of the miRNAs remained non-differentially expressed. The results revealed that miR-1246, miR-1290 and miR-4728-5p were the most upregulated over time. miR-196b-5p and miR-196a-5p were the most downregulated at 24 h, whereas at 72 h, miR-3924, miR-30e-5p and miR-145-3p showed the highest level of downregulation. In the top significantly enriched KEGG pathways of genes targeted by differentially expressed miRNAs we found, among others, MAPK, RAS, P13K-Akt and renin secretion signaling pathways. Using RT-qPCR, we also showed that SARS-CoV-2 may regulate several predicted host mRNA targets involved in the entry of the virus into host cells (ACE2, TMPRSS2, ADAM17, FURIN), renin-angiotensin system (RAS) (Renin, Angiotensinogen, ACE), innate immune response (IL-6, IFN1β, CXCL10, SOCS4) and fundamental cellular processes (AKT, NOTCH, WNT). Finally, we demonstrated by dual-luciferase assay a direct interaction between miR-1246 and ACE-2 mRNA. This study highlights the modulatory role of miRNAs in the pathogenesis of SARS-CoV-2.

Potential of Nano-Antioxidants and Nanomedicine for Recovery from Neurological Disorders Linked to Long COVID Syndrome

Long-term neurological complications, persisting in patients who cannot fully recover several months after severe SARS-CoV-2 coronavirus infection, are referred to as neurological sequelae of the long COVID syndrome. Among the numerous clinical post-acute COVID-19 symptoms, neurological and psychiatric manifestations comprise prolonged fatigue, "brain fog", memory deficits, headache, ageusia, anosmia, myalgias, cognitive impairments, anxiety, and depression lasting several months. Considering that neurons are highly vulnerable to inflammatory and oxidative stress damages following the overproduction of reactive oxygen species (ROS), neuroinflammation and oxidative stress have been suggested to dominate the pathophysiological mechanisms of the long COVID syndrome. It is emphasized that mitochondrial dysfunction and oxidative stress damages are crucial for the pathogenesis of neurodegenerative disorders. Importantly, antioxidant therapies have the potential to slow down and prevent disease progression. However, many antioxidant compounds display low bioavailability, instability, and transport to targeted tissues, limiting their clinical applications. Various nanocarrier types, e.g., liposomes, cubosomes, solid lipid nanoparticles, micelles, dendrimers, carbon-based nanostructures, nanoceria, and other inorganic nanoparticles, can be employed to enhance antioxidant bioavailability. Here, we highlight the potential of phytochemical antioxidants and other neuroprotective agents (curcumin, quercetin, vitamins C, E and D, melatonin, rosmarinic acid, N-acetylcysteine, and Ginkgo Biloba derivatives) in therapeutic strategies for neuroregeneration. A particular focus is given to the beneficial role of nanoparticle-mediated drug-delivery systems in addressing the challenges of antioxidants for managing and preventing neurological disorders as factors of long COVID sequelae.

Cholinergic deficiency in the cholinergic system as a pathogenetic link in the formation of various syndromes in COVID-19

According to recent data, several mechanisms of viral invasion of the central nervous system (CNS) have been proposed, one of which is both direct penetration of the virus through afferent nerve fibers and damage to the endothelium of cerebral vessels. It has been proven that the SARS-CoV-2 virus affects pathologically not only the human cardiorespiratory system but is also associated with a wide range of neurological diseases, cerebrovascular accidents, and neuromuscular pathologies. However, the observed post-COVID symptom complex in patients, manifested in the form of headache, "fog in the head," high temperature, muscle weakness, lowering blood pressure, does it make us think about the pathophysiological mechanisms that contribute to the development of this clinical picture? One possible explanation is a disruption in the signaling of the acetylcholine system (AChS) in the body. Viral invasions, and in particular COVID-19, can negatively affect the work of the AChS, disrupting its coordination activities. Therefore, the main goal of this literature review is to analyze the information and substantiate the possible mechanisms for the occurrence of post-COVID syndrome in people who have had COVID-19 from the standpoint of AChS dysfunctions.

Toxin-like Peptides from the Bacterial Cultures Derived from Gut Microbiome Infected by SARS-CoV-2-New Data for a Possible Role in the Long COVID Pattern

It has been 3 years since the beginning of the SARS-CoV-2 outbreak, however it is as yet little known how to care for the acute COVID-19 and long COVID patients. COVID-19 clinical manifestations are of both pulmonary and extra-pulmonary types. Extra-pulmonary ones include extreme tiredness (fatigue), shortness of breath, muscle aches, hyposmia, dysgeusia, and other neurological manifestations. In other autoimmune diseases, such as Parkinson's disease (PD) or Alzheimer's Disease (AD), it is well known that role of acetylcholine is crucial in olfactory dysfunction. We have already observed the presence of toxin-like peptides in plasma, urine, and faecal samples from COVID-19 patients, which are very similar to molecules known to alter acetylcholine signaling. After observing the production of these peptides in bacterial cultures, we have performed additional proteomics analyses to better understand their behavior and reported the extended data from our latest in vitro experiment. It seems that the gut microbiome continues to produce toxin-like peptides also after the decrease of RNA SARS-CoV-2 viral load at molecular tests. These toxicological interactions between the gut/human microbiome bacteria and the virus suggest a new scenario in the study of the clinical symptoms in long COVID and also in acute COVID-19 patients. It is discussed that in the bacteriophage similar behavior, the presence of toxins produced by bacteria continuously after viral aggression can be blocked using an appropriate combination of certain drugs.

Is SARS-CoV-2 a Risk Factor of Bipolar Disorder?-A Narrative Review

For 2.5 years we have been facing the coronavirus disease (COVID-19) and its health, social and economic effects. One of its known consequences is the development of neuropsychiatric diseases such as anxiety and depression. However, reports of manic episodes related to COVID-19 have emerged. Mania is an integral part of the debilitating illness-bipolar disorder (BD). Due to its devastating effects, it is therefore important to establish whether SARS-CoV-2 infection is a causative agent of this severe mental disorder. In this narrative review, we discuss the similarities between the disorders caused by SARS-CoV-2 and those found in patients with BD, and we also try to answer the question of whether SARS-CoV-2 infection may be a risk factor for the development of this affective disorder. Our observation shows that disorders in COVID-19 showing the greatest similarity to those in BD are cytokine disorders, tryptophan metabolism, sleep disorders and structural changes in the central nervous system (CNS). These changes, especially intensified in severe infections, may be a trigger for the development of BD in particularly vulnerable people, e.g., with family history, or cause an acute episode in patients with a pre-existing BD.

Comparison of QEEG Findings before and after Onset of Post-COVID-19 Brain Fog Symptoms

Previous research and clinical reports have shown that some individuals after COVID-19 infection may demonstrate symptoms of so-called brain fog, manifested by cognitive impairment and disorganization in behavior. Meanwhile, in several other conditions, related to intellectual function, a specific pattern of changes in electric brain activity, as recorded by quantitative electroencephalography (QEEG) has been documented. We hypothesized, that in post-COVID brain fog, the subjective complaints may be accompanied by objective changes in the QEEG profile. In order to test this hypothesis, we have performed an exploratory study on the academic staff of our University with previous records of QEEG originating in the pre-COVID-19 era. Among them, 20 subjects who revealed neurological problems in the cognitive sphere (confirmed as covid fog/brain fog by a clinical specialist) after COVID-19 infection were identified. In those individuals, QEEG was performed. We observed, that opposite to baseline QEEG records, increased Theta and Alpha activity, as well as more intensive sensimotor rhythm (SMR) in C4 (right hemisphere) in relation to C3 (left hemisphere). Moreover, a visible increase in Beta 2 in relation to SMR in both hemispheres could be documented. Summarizing, we could demonstrate a clear change in QEEG activity patterns in individuals previously not affected by COVID-19 and now suffering from post-COVID-19 brain fog. These preliminary results warrant further interest in delineating their background. Here, both neuroinflammation and psychological stress, related to Sars-CoV2-infection may be considered. Based on our observation, the relevance of QEEG examination as a supportive tool for post-COVID clinical workup and for monitoring the treatment effects is also to be explored.

Understanding the Pivotal Role of the Vagus Nerve in Health from Pandemics

The COVID-19 pandemic seems endless with the regular emergence of new variants. Is the SARS-CoV-2 virus particularly evasive to the immune system, or is it merely disrupting communication between the body and the brain, thus pre-empting homeostasis? Retrospective analysis of the COVID-19 and AIDS pandemics, as well as prion disease, emphasizes the pivotal but little-known role of the 10th cranial nerve in health. Considering neuroimmunometabolism from the point of view of the vagus nerve, non-invasive bioengineering solutions aiming at monitoring and stimulating the vagal tone are subsequently discussed as the next optimal and global preventive treatments, far beyond pandemics.

New-Onset Ocular Myasthenia Gravis After Booster Dose of COVID-19 Vaccine

Coronavirus disease 2019 (COVID-19) vaccines have been reported as possible triggers of the production of antibodies pathogenic to the peripheral nerve and neuromuscular junction. We report on a patient who experienced vertical diplopia three weeks after the booster dose of the Pfizer-BioNTech vaccine (Comirnaty®). The diagnosis of myasthenia gravis (MG) was established based on highly positive antibodies to the nicotinic acetylcholine receptor (nAChR). Treatment with pyridostigmine and prednisone was started with gradually raising doses. On a follow-up exam two months after treatment initiation, clinical improvement was noted with an almost normal bulbomotor examination. The occurrence of diplopia following COVID-19 vaccination should raise suspicion of new-onset ocular MG and testing for anti-nAChR antibodies is advised.

Special Issue: Cholinergic Control of Inflammation

Inflammation caused by infection, tissue trauma, and disease states such as arthritis and inflammatory bowel disease is perceived by the Central nervous System (CNS) through different routes that, by means of neural reflex circuits, regulate the immune system response [...]

SARS-CoV-2 infection in patients with neuroimmunological disorders in a tertiary referral centre from the north of Portugal

Introduction

The impact of COVID-19 in patients with neuroimmunological disorders is not fully established. There is some evidence suggesting an increased risk of more severe infection associated with the use of immunosuppressors in this population.

Objective

To characterize SARS-CoV-2 infection in patients followed in the neuroimmunology outpatient clinic of a tertiary centre from the north of Portugal.

Methods

Retrospective analysis of neuroimmunological patients with PCR-proven SARS-CoV-2 infection during the observational period of 20 months.

Results

Ninety-one patients were infected, 68.1% female, with a mean age of 48.9±16.7 years. The median disease duration was 11.0 (IQR 6.0-19.0) years. Sixty-one patients (67.0%) had Multiple Sclerosis, of which 50 with relapsing-remitting course, 12 (13.2%) Myasthenia Gravis (MG), 6 (6.6%) Autoimmune Encephalitis and 6 (6.6%) Chronic Inflammatory Demyelinating Polyneuropathy. Seventy-six patients (83.5%) were taking disease-modifying therapy, 77.6% of which were on immunosuppressants, including anti-CD20 in 12 (13.2%). Most patients had mild COVID-19 (84.6%), with 3 cases (3.3%) of severe disease and, 7 cases (7.7%) of critical disease being reported. In total, 13 patients were hospitalized and 4 died. Patients with severe to critical disease were significantly older than patients with milder forms (69.4±21.0 versus 46.5±14.4 years, p<0.01). MG was also associated with more severe disease (p=0.02). There was no association between comorbidities or use of immunosuppressors (including anti-CD20) and COVID-19 severity.

Conclusions

Greater age and MG were associated with severe or critical COVID-19. We found no association between a specific DMT, including anti-CD20, and outcome. Clinical recovery was achieved by 93.4%.

Significant Increase in Blood Pressure Following BNT162b2 mRNA COVID-19 Vaccination among Healthcare Workers: A Rare Event

This brief report examined the frequency and characteristics of a significant blood-pressure (BP) increase after Pfizer-BioNTech BNT162b2 vaccination among healthcare workers who were advised to measure their BP at home. A total of 797 participants (mean age 48.1 ± 10.8 years, 63% women, 39% smokers) were included in the analysis. Seven participants reported an increase in their BP (three in the range of grade 2 and four in the range of grade 3 hypertension). Only one participant had a history of treated hypertension. The BP increase was observed at the end of the first week after the first dose, lasted for 3 to 4 days, and recurred promptly after the second dose. Only one case required hospitalization, mainly due to a history of cardiovascular disease (follow-up). Individuals experiencing a BP increase compared with those not reporting issues with their BP had a higher mean age and similar distribution of sex and non-smoking status. In conclusion, a significant BP increase after Pfizer-BioNTech vaccination seems to be rare and of a benign and transient nature. Monitoring the BP before and after vaccination might be advisable only for selected individuals with a high cardiovascular risk.

Post-Coronavirus Disease 2019 Triggers the Appearance of Mixed Polyneuropathy and Brain Fog: A Case Report

Coronavirus disease 2019 (COVID-19) can directly or indirectly affect the central and peripheral nervous systems, resulting in cognitive impairment, memory problems, and a wide range of neuromuscular involvement, including neuropathies. However, the long-term neurological complications of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection are not clear. The aim this study was to analyze a case report the presence of neurological sequelae due to post-Coronavirus disease 19 in a patient without apparent previous neurological symptoms. Clinical case: A 46-year-old patient, with no relevant history for the described condition, who, after severe COVID-19 infection, started a mixed neuropathy and mental fog syndrome as the main sequel. Multiple laboratory and imaging studies were performed during and after his hospital stay, and it was corroborated by an electromyography that it occurred from a neuropathy triggered by COVID-19 infection. Conclusions: This case provides additional evidence that mixed neuropathy and brain fog syndrome are potential complications of post-coronavirus disease 2019 syndrome. The neurological sequelae that manifest after a COVID-19 episode can be rapidly enhanced as a consequence of another alteration in some systems of the organism. However, future studies are necessary to elucidate the incidence of these neurological complications, their pathophysiological mechanisms and their therapeutic options.

Reply to Cafiero et al. Comment on "Kopańska et al. Disorders of the Cholinergic System in COVID-19 Era-A Review of the Latest Research. Int. J. Mol. Sci. 2022, 23, 672"

We have carefully read the Letter to the Editor by Concetta Cafiero, Alessandra Micera, Agnese Re, Beniamino Schiavone, Giulio Benincasa, and Raffaele Palmirotta related to our paper entitled "Disorders of the Cholinergic System in COVID-19 Era-A Review of the Latest Research" [...].

Comment on Kopańska et al. Disorders of the Cholinergic System in COVID-19 Era-A Review of the Latest Research. Int. J. Mol. Sci. 2022, 23, 672

We read the recent review article by Marta Kopańska et al. [...].