Neurologic manifestations in hospitalized patients with COVID-19 in Mexico City

Unveiling the Oral Lesions, Dysgeusia and Osteonecrosis Related to COVID-19: A Comprehensive Systematic Review

Background/Objectives: The oral cavity has garnered increasing attention as a site for viral infection and related pathological manifestations in coronavirus disease-19. This article aims to provide a comprehensive overview of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2)-related oral manifestations, including taste disturbances, oral lesions and osteonecrosis. Methods: A search was conducted up to September 2024 according to PRISMA (Preferred Reporting Items for Systematic Reviews) guidelines using the databases PubMed and Scopus. All the observational, case-series, case-report and cross-sectional studies written in English on oral manifestations related to COVID-19 disease and long-COVID disease were included. All other types of studies and studies based on oral manifestation after COVID-19 vaccination and oral impairment due to lockdown were excluded. The risk of bias of included studies was assessed using the Joanna Briggs Appraisal checklist. Results: A total of 104 articles including 23 case-report, 15 case-series, 8 case-control, 18 cohort and 40 cross-sectional studies were selected. The results showed that patients with COVID-19 were found to have a significantly higher prevalence of xerostomia (45-74%) and dysgeusia (32-59%) compared to non-infected individuals. Regarding oral mucosal lesions, ulcers, candidiasis and herpes simplex infections were frequently observed. As for osteonecrosis, a significant number of patients with COVID-19-associated rhinomaxillary mucormycosis presented with maxillary osteonecrosis due to fungal infection, primarily mucormycosis. The methodological quality of most of the studies was moderate/high. Conclusions: COVID-19 has been associated with a range of oral manifestations. The complex interplay of viral infection, immune response, medication use and stress likely contributes to these oral complications. Early recognition and management of these oral manifestations are crucial for improving patient outcomes and developing targeted preventive and therapeutic strategies for COVID-19-related oral health issues.

Correction: Neurologic manifestations in hospitalized patients with COVID-19 in Mexico City

[This corrects the article DOI: 10.1371/journal.pone.0247433.].

Does COVID-19 Trigger the Risk for the Development of Parkinson's Disease? Therapeutic Potential of Vitamin C

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which was proclaimed a pandemic by the World Health Organization (WHO) in March 2020. There is mounting evidence that older patients with multimorbidity are more susceptible to COVID-19 complications than are younger, healthy people. Having neuroinvasive potential, SARS-CoV-2 infection may increase susceptibility toward the development of Parkinson's disease (PD), a progressive neurodegenerative disorder with extensive motor deficits. PD is characterized by the aggregation of α-synuclein in the form of Lewy bodies and the loss of dopaminergic neurons in the dorsal striatum and substantia nigra pars compacta (SNpc) of the nigrostriatal pathway in the brain. Increasing reports suggest that SARS-CoV-2 infection is linked with the worsening of motor and non-motor symptoms with high rates of hospitalization and mortality in PD patients. Common pathological changes in both diseases involve oxidative stress, mitochondrial dysfunction, neuroinflammation, and neurodegeneration. COVID-19 exacerbates the damage ensuing from the dysregulation of those processes, furthering neurological complications, and increasing the severity of PD symptomatology. Phytochemicals have antioxidant, anti-inflammatory, and anti-apoptotic properties. Vitamin C supplementation is found to ameliorate the common pathological changes in both diseases to some extent. This review aims to present the available evidence on the association between COVID-19 and PD, and discusses the therapeutic potential of vitamin C for its better management.

Predictors of the severity of the course of COVID-19: demographic factors, clinical signs and laboratory markers

Introduction. The Coronavirus Disease 2019 (COVID-19) pandemic has had a significant impact on global healthcare, with high mortality and severe complications remaining a major concern. Understanding the predictors of COVID-19 severity may improve patient management and outcomes. While considerable research has focused on the pathogenesis of the virus and vaccine development, the identification of reliable demographic, clinical and laboratory predictors of severe disease remains critical.Hypothesis. Specific demographic factors, clinical signs and laboratory markers can reliably predict the severity of COVID-19. A comprehensive analysis integrating these predictors could provide a more accurate prognosis and guide timely interventions.Aim. The aim of this study is to identify and evaluate the demographic, clinical and laboratory factors that can serve as reliable predictors of severe COVID-19, thereby aiding in the prediction and prevention of adverse outcomes.Methodology. The methods of analysis, synthesis, generalization and descriptive statistics were used to achieve this objective.Results. The analysis showed that demographic factors such as age over 60 and male sex are significant predictors of severe COVID-19. Clinical predictors include respiratory symptoms, especially dyspnoea, and comorbidities such as hypertension, coronary artery disease, chronic obstructive pulmonary disease, respiratory failure, asthma, diabetes mellitus and obesity. Laboratory markers with high prognostic value include elevated levels of C-reactive protein, interleukin-6, ferritin, neutrophil/lymphocyte ratio, d-dimer, aspartate aminotransferase enzyme and decreased lymphocyte count.Conclusion. The study concludes that a holistic approach incorporating demographic, clinical and laboratory data is essential to accurately predict the severity of COVID-19. This integrated model may significantly improve patient prognosis by facilitating early identification of high-risk individuals and allowing timely, targeted interventions. The results highlight the importance of comprehensive patient assessment in managing and mitigating the impact of COVID-19.

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

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

COVID-19 and Comorbidities: What Has Been Unveiled by Metabolomics?

The COVID-19 pandemic has brought about diverse impacts on the global population. Individuals with comorbidities were more susceptible to the severe symptoms caused by the virus. Within the crisis scenario, metabolomics represents a potential area of science capable of providing relevant information for understanding the metabolic pathways associated with the intricate interaction between the viral disease and previous comorbidities. This work aims to provide a comprehensive description of the scientific production pertaining to metabolomics within the specific context of COVID-19 and comorbidities, while highlighting promising areas for exploration by those interested in the subject. In this review, we highlighted the studies of metabolomics that indicated a variety of metabolites associated with comorbidities and COVID-19. Furthermore, we observed that the understanding of the metabolic processes involved between comorbidities and COVID-19 is limited due to the urgent need to report disease outcomes in individuals with comorbidities. The overlap of two or more comorbidities associated with the severity of COVID-19 hinders the comprehension of the significance of each condition. Most identified studies are observational, with a restricted number of patients, due to challenges in sample collection amidst the emergent situation.

Topographical Distribution of Neuroanatomical Abnormalities Following COVID-19 Invasion : A Systematic Literature Review

PURPOSE

This systematic review is aimed at synthesising the literature base to date on the frequency and topographical distribution of neuroanatomical changes seen on imaging following COVID-19 invasion with a focus on both the acute and chronic phases of the disease.

METHODS

In this study, 8 databases were systematically searched to identify relevant articles published from December 2019 to March 2022 and supplemented with a manual reference search. Data were extracted from the included studies and narrative synthesis was employed to integrate the findings.

RESULTS

A total of 110 studies met the inclusion criteria and comprised 119,307 participants (including 31,073 acute and 143 long COVID-19 patients manifesting neurological alterations) and controls. Considerable variability in both the localisation and nature of neuroanatomical abnormalities are noted along the continuum with a wide range of neuropathologies relating to the cerebrovascular/neurovascular system, (sub)cortical structures (including deep grey and white matter structures), brainstem, and predominant regional and/or global alterations in the cerebellum with varying degrees of spinal involvement.

CONCLUSION

Structural regional alterations on neuroimaging are frequently demonstrated in both the acute and chronic phases of SARS-CoV‑2 infection, particularly prevalent across subcortical, prefrontal/frontal and cortico-limbic brain areas as well as the cerebrovascular/neurovascular system. These findings contribute to our understanding of the acute and chronic effects of the virus on the nervous system and has the potential to provide information on acute and long-term treatment and neurorehabilitation decisions.

SARS-CoV and SARS-CoV-2 display limited neuronal infection and lack the ability to transmit within synaptically connected axons in stem cell-derived human neurons

Sarbecoviruses such as SARS and SARS-CoV-2 have been responsible for two major outbreaks in humans, the latter resulting in a global pandemic. While sarbecoviruses primarily cause an acute respiratory infection, they have been shown to infect the nervous system. However, mechanisms of sarbecovirus neuroinvasion and neuropathogenesis remain unclear. In this study, we examined the infectivity and trans-synaptic transmission potential of the sarbecoviruses SARS and SARS-CoV-2 in human stem cell-derived neural model systems. We demonstrated limited ability of sarbecoviruses to infect and replicate in human stem cell-derived neurons. Furthermore, we demonstrated an inability of sarbecoviruses to transmit between synaptically connected human stem cell-derived neurons. Finally, we determined an absence of SARS-CoV-2 infection in olfactory neurons in experimentally infected ferrets. Collectively, this study indicates that sarbecoviruses exhibit low potential to infect human stem cell-derived neurons, lack an ability to infect ferret olfactory neurons, and lack an inbuilt molecular mechanism to utilise retrograde axonal trafficking and trans-synaptic transmission to spread within the human nervous system.

Atypical Complications during the Course of COVID-19: A Comprehensive Review

COVID-19 is primarily a respiratory disease, but numerous studies have indicated the involvement of various organ systems during the course of illness. We conducted a comprehensive review of atypical complications of COVID-19 with their incidence range (IR) and their impact on hospitalization and mortality rates. We identified 97 studies, including 55 research articles and 42 case studies. We reviewed four major body organ systems for various types of atypical complications: (i) Gastro-intestinal (GI) and hepatobiliary system, e.g., bowel ischemia/infarction (IR: 1.49-83.87%), GI bleeding/hemorrhage (IR: 0.47-10.6%), hepatic ischemia (IR: 1.0-7.4%); (ii) Neurological system, e.g., acute ischemic stroke/cerebral venous sinus thrombosis/cerebral hemorrhage (IR: 0.5-90.9%), anosmia (IR: 4.9-79.6%), dysgeusia (IR: 2.8-83.38%), encephalopathy/encephalitis with or without fever and hypoxia (IR: 0.19-35.2%); (iii) Renal system, e.g., acute kidney injury (AKI)/acute renal failure (IR: 0.5-68.8%); (iv) Cardiovascular system, e.g., acute cardiac injury/non-coronary myocardial injury (IR: 7.2-55.56%), arrhythmia/ventricular tachycardia/ventricular fibrillation (IR: 5.9-16.7%), and coagulopathy/venous thromboembolism (IR: 19-34.4%). This review encourages and informs healthcare practitioners to keenly monitor COVID-19 survivors for these atypical complications in all major organ systems and not only treat the respiratory symptoms of patients. Post-COVID effects should be monitored, and follow-up of patients should be performed on a regular basis to check for long-term complications.

Neurological complications during the Omicron COVID-19 wave in China: A cohort study

BACKGROUND AND PURPOSE

The aim was to investigate the neurological complications associated with coronavirus disease 19 (COVID-19) during the 2022 Omicron wave.

METHODS AND ANALYSIS

The medical records of a cohort of people admitted to neurological wards of three participating tertiary centres in Sichuan from 12 December 2022 to 12 January 2023 were reviewed. Demographics and clinical data were obtained and analysed with an interest in COVID-19-related new-onset or worse neurological symptoms. The current data were also compared in two centres with similar data from the same period 12 months earlier.

RESULTS

In all, 790 people were enrolled, of whom 436 were positive for COVID-19. Ninety-nine had new onset COVID-related neurological problems, or their known neurological condition deteriorated during the wave. There was a significant difference in demographics from the findings amongst admissions 12 months earlier as there was an increase in the average age, the incidence of encephalitis and encephalopathy, and mortality rates. One hundred and one received COVID-specific antivirals, intravenous glucocorticoids and intravenous immunoglobulin therapy. No differences were seen between these and those who did not use them.

CONCLUSION

New-onset neurological conditions, particularly encephalitis and encephalopathy, increased significantly during this period. Deterioration of existing neurological conditions, such as seizure exacerbation, was also observed. A large-scale treatment trial of people with COVID-19 infection presenting with neurological disorders is still needed.

Prevalence and risk factors for seizures in adult COVID-19 patients: A meta-analysis

Seizures may be one of the neurological consequences of COVID-19. The present study aims to review the prevalence of seizures in COVID-19 patients considering sex and geographical origin. A review protocol was submitted to the PROSPERO database (CRD42021281467). PRISMA statement was used to report the meta-analysis. The authors selected studies for the meta-analysis by searching the principal databases. Studies were eligible if they reported seizures in COVID-19 patients, regardless of study design. Data were analyzed by proportion meta-analysis with a 95 % confidence interval (95 % CI). Cochran's Q and Higgins' I2 were used to measure heterogeneity. R software was used for meta-analysis. Subgroup analyses were carried out for sex, geographical origin of the subjects, and illness severity. A checklist for prevalence studies was used to assess the risk of bias in the included studies. A total of 32 studies (n = 251,997 analyzed patients) were included in this meta-analysis. A prevalence of 1.03 % (95 % CI 0.73 to 1.37, I2 = 93 %, p < 0.001) was found. No statistically significant differences were found in the analysis by geographical subgroups. Men were found to be less likely to had COVID-19 seizures (OR = 0.75, 95 % CI 0.21-2.74), while mildly ill patients were found to be more likely to had COVID-19-induced seizures (OR = 2.08, 95 % CI 0.86-5.06). Our results show a slight prevalence of seizures in COVID-19 patients. In addition, we found that the groups analyzed had differences in the odds of having COVID-19-induced seizures.

Neurological Manifestations and Complications of the Central Nervous System as Risk Factors and Predictors of Mortality in Patients Hospitalized with COVID-19: A Cohort Study

The aim of this study was to analyze the risk factors and predictors of mortality in a retrospective cohort of patients with coronavirus disease (COVID-19) who presented central nervous system (CNS) manifestations and complications when admitted to hospital. Patients hospitalized from 2020 to 2022 were selected. Demographic variables; history of neurological, cardiological and pulmonary manifestations; comorbidities; prognostic severity scales; and laboratory tests were included. Univariate and adjusted analyses were performed to determine risk factors and predictors of mortality. A forest plot diagram was used to show the strength of the associated risk factors. The cohort included 991 patients; at admission, 463 patients presented CNS damage and of these, 96 hospitalized patients presented de novo CNS manifestations and complications. We estimate a general mortality of 43.7% (433/991) and 77.1% (74/96), for hospitalized patients with de novo CNS manifestations and complications, respectively. The following were identified as risks for the development of hospital CNS manifestations and complications when in hospital: an age of ≥64 years, a history of neurological disease, de novo deep vein thrombosis, D-dimer ≥ 1000 ng/dL, a SOFA ≥ 5, and a CORADS 6. In a multivariable analysis, the mortality predictors were an age of ≥64 years, a SOFA ≥ 5, D-dimer ≥ 1000 ng/mL and hospital CNS manifestations and complications when admitted to hospital. Old age, being hospitalized in critical condition, and having CNS manifestations and complications in hospital are predictors of mortality in hospitalized patients with COVID-19.

Literature Review-Transthoracic Echocardiography, Computed Tomography Angiography, and Their Value in Clinical Decision Making and Outcome Predictions in Patients with COVID-19 Associated Cardiovascular Complications

The sudden outbreak of the COVID-19 pandemic posed a great threat to the world's healthcare systems. It resulted in the development of new methods and algorithms for the diagnosis and treatment of both COVID-19 and its complications. Diagnostic imaging played a crucial role in both cases. Among the most widely used examinations are transthoracic echocardiography (TTE) and computed tomography angiography (CTA). Cardiovascular complications in COVID-19 are frequently associated with a severe inflammatory response, which results in acute respiratory failure, further leading to severe complications of the cardiovascular system. Our review aims to discuss the value of TTE and CTA in clinical decision making and outcome prediction in patients with COVID-19-associated cardiovascular complications. Our review revealed the high clinical value of various TTE findings and their association with mortality and the prediction of patients' clinical outcomes, especially when used with other laboratory parameters. The strongest association between increased mortality and findings in TTE was observed for tachycardia and decreased left ventricular ejection fraction (odds ratio (OR) 24.06) and tricuspid annular plane systolic excursion/pulmonary artery systolic pressure ratio (TAPSE/PASP ratio) < 0.31 mm/mmHg (OR 17.80). CTA is a valuable tool in diagnosing COVID-19-associated pulmonary embolism, but its association with mortality and its predictive role should always be combined with laboratory findings and patients' medical history. D-dimers > 3000 ng/mL were found as the strongest predictors of pulmonary embolism (PE) (OR 7.494). Our review indicates the necessity for an active search for cardiovascular complications in patients with severe COVID-19, as they are linked with an increased probability of fatal outcomes.

Post-COVID-19 syndrome and quality of life impairment in severe COVID-19 Mexican patients

Introduction

Post-COVID-19 syndrome (PCS) usually occurs 3 months after the onset of COVID-19 with a symptom duration of at least 2 months without an alternative diagnosis.

Objective

This study aimed to describe the prevalence, characteristics, and impact on the quality of life (QoL) of post-COVID-19 syndrome in patients with a history of hospitalization for COVID-19.

Materials and methods

We conducted a cross-sectional study. Patients who required hospitalization due to COVID-19 between March 2020 and October 2021 were invited to answer a PCS questionnaire and the EQ-5D instrument. A total of 246 patients were included: 187 (76%) met the definition of PCS and 54% were men, with a median age of 50 years (IQR 41-63).

Results

From 187 patients with PCS, the median time to symptom onset after hospital discharge was 1 day (IQR 1-20), and the median symptom duration was 150 days (IQR 90-225). A total of 27 different symptoms were reported; the most frequent were difficulty concentrating (81%), dyspnea (75%), arthralgia (71%), fatigue (68%), and hair loss (60%). Some symptoms, such as difficulty concentrating, arthralgia/myalgia, and hair loss, were more prevalent in women with PCS. Patients with PCS had a higher frequency of tobacco smoking (37 vs. 4%, p = 0.02) and increased severity of lung involvement in the initial chest tomography (75 vs. 58%, p = 0.01) than those without PCS. Patients with PCS were less likely to receive antivirals (15.5 vs. 27%, p = 0.04). No difference between ICU admission, mechanical ventilation, and length of hospital stay was found. Patients with PCS had a lower visual analog scale result for EQ-5D vs. those without (80 [IQR 70-90] vs. 89.5 [IQR 75-90], p = 0.05). All five QoL dimensions were affected in PCS patients, showing increased pain/discomfort (67 vs. 39%, p = < 0.001), difficulties in performing usual activities (39.2 vs. 20.3%, p = 0.03), and anxiety/depression (57.5 vs. 37%, p = 0.02).

Conclusion

PCS occurred in 76% of hospitalized patients with prolonged duration and QoL impairment. Neurological symptoms such as difficulty concentrating were the most frequent symptoms. Timely diagnostic and therapeutic interventions are required.

Hospitalized COVID-19 patients with diabetes have an increased risk for pneumonia, intensive care unit requirement, intubation, and death: A cross-sectional cohort study in Mexico in 2020

Background

Diabetes mellitus is a chronic health condition that has been linked with an increased risk of severe illness and mortality from COVID-19. In Mexico, the impact of diabetes on COVID-19 outcomes in hospitalized patients has not been fully quantified. Understanding the increased risk posed by diabetes in this patient population can help healthcare providers better allocate resources and improve patient outcomes.

Objective

The objective of this study was to quantify the extent outcomes (pneumonia, intensive care unit [ICU] stay, intubation, and death) are worsened in diabetic patients with COVID-19.

Methods

Between April 14, 2020 and December 20, 2020 (last accessed), data from the open-source COVID-19 database maintained by the Mexican Federal Government were examined. Utilizing hospitalized COVID-19 patients with complete outcome data, a retrospective cohort study (N = 402,388) was carried out. In relation to COVID-19, both univariate and multivariate logistic regression were used to investigate the effect of diabetes on specific outcomes.

Results

The analysis included 402,388 adults (age >18) with confirmed hospitalized COVID-19 cases with mean age 46.16 (standard deviation = 15.55), 214,161 (53%) male. The outcomes delineated included pneumonia (N = 88,064; 22%), ICU requirement (N = 23,670; 6%), intubation (N = 23,670; 6%), and death (N = 55,356; 14%). After controlling for confounding variables diabetes continued to be an independent risk factor for both pneumonia (odds ratio [OR]: 1.8, confidence interval [CI]: 1.76-1.84, p < 0.01), ICU requirement (OR: 1.09, CI: 1.04-1.14, p < 0.01), intubation (OR: 1.07, CI: 1.04-1.11, p < 0.01), and death (OR: 1.88, CI: 1.84-1.93, p < 0.01) in COVID-19 patients.

Conclusions

According to the study, all outcomes (pneumonia, ICU requirement, intubation, and death) were greater among hospitalized individuals with diabetes and COVID-19. Additional study is required to acquire a better understanding of how diabetes affects COVID-19 outcomes and to develop practical mitigation techniques for the risk of severe sickness and complications in this particular patient population.

Associations of the neutrophil/lymphocyte ratio, monocyte/ lymphocyte ratio, and platelet/lymphocyte ratio with COVID-19 disease severity in patients with neurological symptoms: A cross-sectional monocentric study

Objectives

Data are limited regarding the relationship of neutrophil/lymphocyte ratio (NLR), monocyte/lymphocyte ratio (MLR), and platelet/ lymphocyte ratio (PLR) with neurological symptoms (NS) in COVID-19 patients. This study is the first to assess the utility of the NLR, MLR, and PLR for predicting COVID-19 severity in infected patients with NS.

Materials and Methods

Consecutive 192 PCR-positive COVID-19 patients with NS were included in this cross-sectional and prospective study. The patients were classified into the non-severe and severe groups. We analyzed routinely complete blood count in these groups in terms of COVID-19 disease severity.

Results

Advanced age, a higher body mass index, and comorbidities were significantly more common in the severe group (P < 0.001). Among the NS, anosmia (P = 0.001) and memory loss (P = 0.041) were significantly more common in the non-severe group. In the severe group, the lymphocytes and monocyte counts and the hemoglobin level were significantly lower, while the neutrophil count, NLR, and PLR were significantly higher (all P < 0.001). In the multivariate model, advanced age and a higher neutrophil count were independently associated with severe disease (both P < 0.001) but the NLR and PLR were not (both P > 0.05).

Conclusion

We found positive associations of COVID-19 severity with the NLR and PLR in infected patients with NS. Further research is required to shed more light on the role of neurological involvement in disease prognosis and outcomes.

DOES AUDIOVESTIBULAR POST-COVID SYNDROME EXIST?

The purpose of this study was to present and analyze patients with audiovestibular post COVID-19 syndrome, and highlight the most characteristic and most common findings. We analyzed 87 patients aged between 20 and 86 years who presented to the Audiology Division between February 1, 2021 and July 1, 2021 after having been isolated due to the SARS-CoV-2 infection. Study patients presented with complaints of persistent hearing loss, tinnitus, and vertigo, lasting for more than 3 months. Study results showed that there was acute sensorineural hearing loss in 4 patients during the SARS-CoV-2 infection. None of the patients experienced complete hearing recovery after 3 months. High frequency hearing loss (at 4 kHz and 6 kHz) occurred bilaterally, and was found in 52 patients. This finding of gradual hearing loss was both the most characteristic and most common in COVID patients. Extensive damage can directly occur to inner ear structures, including hair cells, the Corti organ, and the cochlear nerve because of this viral infection. A total of 73 patients had tinnitus. 68 patients had unilateral tinnitus, and only 5 patients had bilateral tinnitus. Exacerbation of tinnitus was recorded in 12 patients and new-onset tinnitus in 61 patients. Vertigo occurred in 9 patients, all of which were new-onset. A conclusion of our research is that audiovestibular post-COVID syndrome does exist. Further research with more patients and over a longer period is needed to obtain a better and longer effect on the audiovestibular system and audiovestibular complications, as well as an insight into possible recovery.

Neurological Manifestations of hospitalized patients with mild to moderate infection with SARS-CoV-2 Omicron variant in Shanghai, China

BACKGROUND

Accumulating studies demonstrated that patients with coronavirus disease 2019(COVID-19) could develop a variety of neurological manifestations and long-term neurological sequelae, which may be different from the strains. At the peak of the Omicron variant outbreak in Shanghai, China, no relevant epidemiological data about neurological manifestations associated with this strain was reported.

OBJECTIVE

To investigate neurological manifestations and related clinical features in patients with mild to moderate COVID-19 patients with Omicron variant.

METHODS

A self-designed clinical information registration form was used to gather the neurological manifestations of mild to moderate COVID-19 patients admitted to a designated hospital in Shanghai from April 18, 2022 to June 1, 2022. Demographics, clinical presentations, laboratory findings, treatments and clinical outcomes were compared between patients with and without neurological manifestations.

RESULTS

One hundred sixty-nine(48.1 %) of 351 patients diagnosed with mild to moderate COVID-19 exhibited neurological manifestations, the most common of which were fatigue/weakness(25.1 %) and myalgia(20.7 %), whereas acute cerebrovascular disease(0.9 %), impaired consciousness(0.6 %) and seizure(0.6 %) were rare. Younger age(p = 0.001), female gender(p = 0.026) and without anticoagulant medication(p = 0.042) were associated with increasing proportions of neurological manifestations as revealed by multivariate logistic regressions. Patients with neurological manifestations had lower creatine kinase and myoglobin levels, as well as higher proportion of patchy shadowing on chest scan. Vaccination status, clinical classification of COVID-19 and clinical outcomes were similar between the two groups.

CONCLUSIONS

Nearly half of the involved patients have neurological manifestations which were relatively subjective and closely associated with younger age, female gender and without anticoagulation. Patients with neurologic manifestations may be accompanied by increased lung patchy shadowing.

Association between nutritional therapy and complications in patients diagnosed with COVID-19 followed in the state of Pernambuco

Objective: To analyze the association between nutritional therapy and complications in patients diagnosed with COVID-19 followed in Pernambuco. Methods: A prospective cohort study was conducted to investigate secondary data from multicenter research from June 2020 to June 2021. Patients of both sexes over 18 years old were hospitalized for COVID-19 in wards or intensive care units of eight hospitals. Sociodemographic and economic data, nutritional status, nutritional therapy, gastrointestinal complications, and clinical outcome were collected during admission and at the end of hospitalization. Results: The sample consisted of 272 patients, with a median age of 67 years (IQR 54 - 76), equally distributed between men and women (50.4% vs. 49.6%). A higher frequency of overweight/obesity (40.31%) was observed. The most frequent alterations were inappetence (12.88%) and dysgeusia (8.28%). It was observed that 84.6% received an early diet, the caloric adequacy varied between 72.1% and 60.7%, the oral route between 82.4% and 70.7%, the majority (58%) received up to 1.3 g of protein per day, and 46.7% died. Caloric adequacy was associated with dysgeusia (p = 0.040) and clinical outcome (p = 0.044) and tended to be associated with vomiting (p = 0.077). No association was found with proteins. Conclusion: Nutritional therapy is associated with gastrointestinal symptoms such as vomiting and dysgeusia and the clinical outcome of patients with COVID-19.

When to test for COVID-19 using real-time reverse transcriptase polymerase chain reaction: a systematic review

OBJECTIVES

The aim of this study was to evaluate the time in days between symptom onset and first positive real-time reverse transcriptase polymerase chain reaction (RT-PCR) result for COVID-19.

METHODS

This systematic review was conducted in the MEDLINE (PubMed), Embase, and Scopus databases using the following descriptors: "COVID-19", "SARS-CoV-2", "coronavirus", "RT-PCR", "real time PCR", and "diagnosis".

RESULTS

The included studies were conducted in 31 different countries and reported on a total of 6831 patients. The median age of the participants was 49.95 years. The three most common symptoms were fever, cough, and dyspnea, which affected 4012 (58.68%), 3192 (46.69%), and 2009 patients (29.38%), respectively. Among the 90 included studies, 13 were prospective cohorts, 15 were retrospective cohorts, 36 were case reports, 20 were case series, and six were cross-sectional studies. The overall mean time between symptom onset and positive test result was 6.72 days. Fourteen articles were analyzed separately for the temporal profile of RT-PCR test results; the best performance was on days 22-24, when 98% of test results were positive.

CONCLUSION

These findings corroborate the RT-PCR COVID-19 testing practices of some health units. In addition, the most frequently described symptoms of these patients can be considered the initial symptoms of infection and used in decision-making about RT-PCR testing.

Therapeutic prospects of ceRNAs in COVID-19

Since the end of 2019, COVID-19 caused by SARS-CoV-2 has spread worldwide, and the understanding of the new coronavirus is in a preliminary stage. Currently, immunotherapy, cell therapy, antiviral therapy, and Chinese herbal medicine have been applied in the clinical treatment of the new coronavirus; however, more efficient and safe drugs to control the progress of the new coronavirus are needed. Long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) may provide new therapeutic targets for novel coronavirus treatments. The first aim of this paper is to review research progress on COVID-19 in the respiratory, immune, digestive, circulatory, urinary, reproductive, and nervous systems. The second aim is to review the body systems and potential therapeutic targets of lncRNAs, miRNAs, and circRNAs in patients with COVID-19. The current research on competing endogenous RNA (ceRNA) (lncRNA-miRNA-mRNA and circRNA-miRNA-mRNA) in SARS-CoV-2 is summarized. Finally, we predict the possible therapeutic targets of four lncRNAs, MALAT1, NEAT1, TUG1, and GAS5, in COVID-19. Importantly, the role of PTEN gene in the ceRNA network predicted by lncRNA MALAT1 and lncRNA TUG1 may help in the discovery and clinical treatment of effective drugs for COVID-19.

Exacerbation of Pre-existing Neurological Symptoms With COVID-19 in Patients With Chronic Neurological Diseases: An Updated Systematic Review

The neurotropism of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can potentially explain the worsening of symptoms in patients with a history of neurological conditions such as stroke, Parkinson's disease, Alzheimer's, and epilepsy. Several studies have reported that these pre-existing conditions may worsen with a higher frequency of flare-ups, thus resulting in a more significant risk of patient mortality. In this review, we sought to provide an overview of the relationship between pre-existing neurological disorders and COVID-19, focusing on whether the initial infection directly influenced the severity of symptoms. We systematically searched the electronic database PubMed (MEDLINE) and used specific keywords related to our aims from January 2020 to July 2022. All articles published on COVID-19 with keywords pertaining to pre-existing neurological diseases were retrieved and subsequently analyzed. After independent review, the data from 107 articles were selected and evaluated. After analyzing the data from selected articles reviewing the effect of COVID-19 on neurological conditions, we have documented the relationship between said pre-existing neurological diseases, showing an increased risk of hospitalization, admission length, worsening of symptoms, and even mortality in COVID-19 patients.

Neurological Manifestations of SARS-CoV-2 Infection: Protocol for a Sub-analysis of the COVID-19 Critical Care Consortium Observational Study

Introduction

Neurological manifestations and complications in coronavirus disease-2019 (COVID-19) patients are frequent. Prior studies suggested a possible association between neurological complications and fatal outcome, as well as the existence of potential modifiable risk factors associated to their occurrence. Therefore, more information is needed regarding the incidence and type of neurological complications, risk factors, and associated outcomes in COVID-19.

Methods

This is a pre-planned secondary analysis of the international multicenter observational study of the COVID-19 Critical Care Consortium (which collected data both retrospectively and prospectively from the beginning of COVID-19 pandemic) with the aim to describe neurological complications in critically ill COVID-19 patients and to assess the associated risk factors, and outcomes. Adult patients with confirmed COVID-19, admitted to Intensive Care Unit (ICU) will be considered for this analysis. Data collected in the COVID-19 Critical Care Consortium study includes patients' pre-admission characteristics, comorbidities, severity status, and type and severity of neurological complications. In-hospital mortality and neurological outcome were collected at discharge from ICU, and at 28-days.

Ethics and Dissemination

The COVID-19 Critical Care Consortium main study and its amendments have been approved by the Regional Ethics Committee of participating sites. No further approval is required for this secondary analysis.

Trial Registration Number

ACTRN12620000421932.

Neurocognitive and psychiatric post-coronavirus disease 2019 conditions: pathogenic insights of brain dysfunction following severe acute respiratory syndrome coronavirus 2 infection

PURPOSE OF REVIEW

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), can trigger a myriad of neuropsychiatric manifestations. As a 2-year-old disease (at the writing of this manuscript), its long-term cognitive and neuropsychiatric implications, known as post-COVID-19 conditions, are incompletely recognized and mechanistically obscure.

RECENT FINDINGS

Fatigue, anxiety, depression, posttraumatic stress disorder, and cognitive dysfunction are reported more frequently in COVID-19 survivors than in matching, non-COVID-19 population. Risk factors are unclear, including comorbidities, age at COVID-19 onset, or disease severity; women, however, have been reported to be at increased risk than men. Although the frequency of these symptoms decreases over time, at least one in five will have persistent cognitive and neuropsychiatric manifestations one year after recovering from COVID-19.

SUMMARY

Neurocognitive and psychiatric post-COVID-19 long-term conditions are frequent and complex multifactorial sequelae. Several acute and chronic factors such as hypoxemia, cerebral thrombotic and inflammatory endothelial damage, and disruption of the blood-brain barrier (leading to parenchymal translocation of pro-inflammatory molecules, cytokines, and cytotoxic T lymphocytes) are involved, leading to microglial activation and astrogliosis. As an evolving topic, evidence derived from prospective studies will expand our understanding of post-COVID-19 these long-term outcomes.

Stroke Among SARS-CoV-2 Vaccine Recipients in Mexico: A Nationwide Descriptive Study

BACKGROUND AND OBJECTIVES

Information on stroke among severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines remains scarce. We report stroke incidence as an adverse event following immunization (AEFI) among recipients of 79,399,446 doses of 6 different SARS-CoV-2 vaccines (BNT162b2, ChAdOx1 nCov-19, Gam-COVID-Vac, CoronaVac, Ad5-nCoV, and Ad26.COV2-S) between December 24, 2020, and August 31, 2021, in Mexico.

METHODS

This retrospective descriptive study analyzed stroke incidence per million doses among hospitalized adult patients (≥18 years) during an 8-month interval. According to the World Health Organization, AEFIs were defined as clinical events occurring within 30 days after immunization and categorized as either nonserious or serious, depending on severity, treatment, and hospital admission requirements. Acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), and cerebral venous thrombosis (CVT) cases were collected through a passive epidemiologic surveillance system in which local health providers report potential AEFI to the Mexican General Board of Epidemiology. Data were captured with standardized case report formats by an ad hoc committee appointed by the Mexican Ministry of Health to evaluate potential neurologic AEFI against SARS-COV-2.

RESULTS

We included 56 patients (31 female patients [55.5%]) for an overall incidence of 0.71 cases per 1,000,000 administered doses (95% CI 0.54-0.92). Median age was 65 years (interquartile range [IQR] 55-76 years); median time from vaccination to stroke (of any subtype) was 2 days (IQR 1-5 days). In 27 (48.2%) patients, the event was diagnosed within the first 24 hours after immunization. The most frequent subtype was AIS in 43 patients (75%; 0.54 per 1,000,000 doses, 95% CI 0.40-0.73), followed by ICH in 9 (16.1%; 0.11 per 1,000,000 doses, 95% CI 0.06-0.22) and SAH and CVT, each with 2 cases (3.6%; 0.03 per 1,000,000 doses, 95% CI 0.01-0.09). Overall, the most common risk factors were hypertension in 33 (58.9%) patients and diabetes in 22 (39.3%). Median hospital length of stay was 6 days (IQR 4-13 days). At discharge, functional outcome was good (modified Rankin Scale score 0-2) in 41.1% of patients; in-hospital mortality rate was 21.4%.

DISCUSSION

Stroke is an exceedingly rare AEFI against SARS-CoV-2. Preexisting stroke risk factors were identified in most patients. Further research is needed to evaluate causal associations between SARS-COV-2 vaccines and stroke.

Neuropathological Aspects of SARS-CoV-2 Infection: Significance for Both Alzheimer's and Parkinson's Disease

Evidence suggests that SARS-CoV-2 entry into the central nervous system can result in neurological and/or neurodegenerative diseases. In this review, routes of SARS-Cov-2 entry into the brain via neuroinvasive pathways such as transcribrial, ocular surface or hematogenous system are discussed. It is argued that SARS-Cov-2-induced cytokine storm, neuroinflammation and oxidative stress increase the risk of developing neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Further studies on the effects of SARS-CoV-2 and its variants on protein aggregation, glia or microglia activation, and blood-brain barrier are warranted.

NeuroCOVID-19: a critical review

BACKGROUND

The COVID-19 pandemic has challenged neurologists since its early days. Neurology consultation services were then overloaded by emergency department and intensive-care patients with acute neurological syndromes. These complications are better explained today, but the growing number of patients with reported longstanding neurological symptoms constitute an emerging, complex, and still poorly understood phenomenon.

OBJECTIVE

This review summarizes data on relevant neurological manifestations of acute SARS-CoV-2 infection and lasting post-infectious disease, also known as Long COVID. The complex history of Long COVID is examined to illustrate the upsides and challenges imposed by the active participation of patient communities in the production of medical knowledge.

METHODS

Narrative review.

RESULTS

Infection with the severe acute respiratory syndrome coronavirus 2 is associated with encephalopathy/delirium, cerebrovascular disease, headache, and peripheral nervous system involvement. Long COVID is a living concept jointly defined by patient communities, physicians and scientists, including neurologists.

CONCLUSION

Co-production of Long COVID knowledge between scientists and patients has initiated an era of patient-led research and evidence-based activism that acts as a two-edged sword - putting patient's suffering in the spotlight, but with a tradeoff in methodological consistency.

Critical role of acute hypoxemia on the cognitive impairment after severe COVID-19 pneumonia: a multivariate causality model analysis

Background

A high proportion of coronavirus disease 2019 (COVID-19) survivors may develop long-term cognitive impairment. We aimed to develop a multivariate causal model exposing the links between COVID-19-associated biomarkers, illness-related variables, and their effects on cognitive performance.

Methods

In this prospective study, we assess the potential drivers for the development of cognitive impairment in patients with severe COVID-19 pneumonia aged ≥ 18 years at 6-month follow-up after hospital discharge, using the Montreal Cognitive Assessment (MoCA). Patients with pre-existing cognitive impairment were excluded. Laboratory results at hospital admission were clustered by principal component analysis (PCA) and included in a path analysis model evaluating the causal relationship between age, comorbidities, hypoxemia, invasive mechanical ventilation (IMV) requirement, in-hospital delirium, and cognitive performance.

Results

We studied 92 patients: 54 (58.7%) men and 38 (41.3%) women, with median age of 50 years (interquartile range 42–55), among whom 50 (54.4%) tested positive for cognitive impairment at 6-month follow-up. Path analysis revealed a direct link between the thrombo-inflammatory component of PCA (C-reactive protein, fibrinogen, and neutrophils) and hypoxemia severity at hospital admission. Our model showed that low PaO₂/FiO₂ ratio values, unlike the thrombo-inflammatory component, had a direct effect on cognitive performance, independent from age, in-hospital delirium, and invasive mechanical ventilation.

Conclusion

In this study, biomarkers of thrombo-inflammation in COVID-19 and low PaO₂/FiO₂ had a negative effect on cognitive performance 6 months after hospital discharge. These results highlight the critical role of hypoxemia as a driver for impaired cognition in the mid-term.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-021-05798-8.

Central nervous system outcomes of COVID-19

The worldwide pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected an estimated 200 million people with over 4 million deaths. Although COVID-19, the disease caused by the SARS-CoV-2 virus, is primarily a respiratory disease, an increasing number of neurologic symptoms have been reported. Some of these symptoms, such as loss of smell or taste, are mild and non-life threatening, while others, such as stroke or seizure, are more critical. Many of these symptoms remain long after the acute illness has passed, a phenomenon known as "long COVID" or postacute sequelae of SARS-CoV-2 infection (PASC). Neurological symptoms can be difficult to study due to the complexity of the central and peripheral nervous system. These neurologic symptoms can be difficult to identify and quantitate. This narrative review will describe approaches for assessing neurologic manifestations of COVID-19, with examples of the data they provide, as well as some directions for future research to aid in understanding the pathophysiology of COVID-19-related neurological implications.

Non-invasive vagus nerve stimulation for prevention of migraine: The multicenter, randomized, double-blind, sham-controlled PREMIUM II trial

AIM

Evaluate the efficacy and safety of non-invasive vagus nerve stimulation for migraine prevention.

METHODS

After completing a 4-week diary run-in period, adults who had migraine with or without aura were randomly assigned to receive active non-invasive vagus nerve stimulation or sham therapy during a 12-week double-blind period.

RESULTS

Of 336 enrolled participants, 113 (active, n = 56; sham, n = 57) completed ≥70 days of the double-blind period and were ≥66% adherent with treatment, comprising the prespecified modified intention-to-treat population. The COVID-19 pandemic led to early trial termination, and the population was ∼60% smaller than the statistical target for full power. Mean reduction in monthly migraine days (primary endpoint) was 3.12 for the active group and 2.29 days for the sham group (difference, -0.83; p = 0.2329). Responder rate (i.e. the percentage of participants with a ≥50% reduction in migraine days) was greater in the active group (44.87%) than the sham group (26.81%; p = 0.0481). Prespecified subgroup analysis suggested that participants with aura responded preferentially. No serious device-related adverse events were reported.

CONCLUSIONS

These results suggest clinical utility of non-invasive vagus nerve stimulation for migraine prevention, particularly for patients who have migraine with aura, and reinforce the well-established safety and tolerability profile of this therapy.Trial Registration: ClinicalTrials.gov (NCT03716505).

Delirium and Psychiatric Sequelae Associated to SARS-CoV-2 in Asymptomatic Patients With Psychiatric History and Mild Cognitive Impairment as Risk Factors: Three Case Reports

Human coronaviruses have neuroinvasive and neurotropic abilities that might explain psychiatric outcomes in affected patients. We hypothesized that delirium might be the sole clinical manifestation or even the prodrome of a psychiatric episode consistent with the mental history of a few infected patients with a preexisting diagnosed cognitive impairment. We examined three patients with preexisting mild cognitive impairment and delirium at admission for suspected SARS-CoV-2 infection. We diagnosed delirium using DSM-5 and Confusion Assessment Method (CAM) and measured consciousness level by the Glasgow Coma Scale. All the patients had no history of fever, respiratory complications, anosmia or ageusia, meningitis, and negative cerebrospinal fluid analysis for SARS-CoV-2. Our first patient had no psychiatric history, the second reported only a depressive episode, and the third had a history of bipolar disorder dated back to 40 years before. In the first patient, delirium resolved 2 days following the admission. The other two patients recovered in 4 and 14 days, and delirium appeared as the prodrome of a new psychiatric episode resembling past events. Clinicians should monitor the possibility that SARS-CoV-2 presence in the brain might clinically manifest in the form of delirium and acute psychiatric sequelae, even without other systemic symptoms. Psychiatric history and preexisting mild cognitive impairment are to be considered as predisposing factors for COVID-19 sequelae in delirium patients.

Delirium and Associated Factors in a Cohort of Hospitalized Patients With Coronavirus Disease 2019

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic dramatically increased the number of patients requiring treatment in an intensive care unit or invasive mechanical ventilation worldwide. Delirium is a well-known neuropsychiatric complication of patients with acute respiratory diseases, representing the most frequent clinical expression of acute brain dysfunction in critically ill patients, especially in those undergoing invasive mechanical ventilation. Among hospitalized patients with COVID-19, delirium incidence ranges from 11% to 80%, depending on the studied population and hospital setting.

OBJECTIVE

To determine risk factors for the development of delirium in hospitalized patients with COVID-19 pneumonia.

METHODS

We retrospectively studied consecutive hospitalized adult (≥18 y) patients with confirmed COVID-19 pneumonia from March 15 to July 15, 2020, in a tertiary-care hospital in Mexico City. Delirium was assessed by the attending physician or trained nurse, with either the Confusion Assessment Method for the Intensive Care Unit or the Confusion Assessment Method brief version, according to the appropriate diagnostic tool for each hospital setting. Consultation-liaison psychiatrists and neurologists confirmed all diagnoses. We calculated adjusted hazard ratios (aHR) with 95% confidence interval (CI) using a Cox proportional-hazards regression model.

RESULTS

We studied 1017 (64.2% men; median age, 54 y; interquartile range 44-64), of whom 166 (16.3%) developed delirium (hyperactive in 75.3%); 78.9% of our delirium cases were detected in patients under invasive mechanical ventilation. The median of days from admission to diagnosis was 14 (interquartile range 8-21) days. Unadjusted mortality rates between delirium and no delirium groups were similar (23.3% vs. 24.1; risk ratio 0.962, 95% CI 0.70-1.33). Age (aHR 1.02, 95% CI 1.01-1.04; P = 0.006), an initial neutrophil-to-lymphocyte ratio ≥9 (aHR 1.81, 95% CI 1.23-2.65; P = 0.003), and requirement of invasive mechanical ventilation (aHR 3.39, 95% CI 1.47-7.84; P = 0.004) were independent risk factors for in-hospital delirium development.

CONCLUSIONS

Delirium is a common in-hospital complication of patients with COVID-19 pneumonia, associated with disease severity; given the extensive number of active COVID-19 cases worldwide, it is essential to detect patients who are most likely to develop delirium during hospitalization. Improving its preventive measures may reduce the risk of the long-term cognitive and functional sequelae associated with this neuropsychiatric complication.

Delirium and Cognitive Impairment as Predisposing Factors of COVID-19 Infection in Neuropsychiatric Patients: A Narrative Review

SARS-CoV-2 neuroinvasive and neurotropic abilities may underlie delirium onset and neuropsychiatric outcomes. Only a limited number of studies have addressed the potential effect of SARS-CoV-2 infection on mental health so far. Most studies mainly reported the acute onset of mixed neuropsychiatric conditions in patients infected with SARS-CoV-2, characterized by agitated behavior, altered level of consciousness, and disorganized thinking, regardless of psychological or socioeconomic triggering factors. The present narrative review aims to analyze and discuss the mechanisms underlying the neuroinvasive/neurotropic properties of SARS-CoV-2 and the subsequent mental complications. Delirium appeared as a clinical manifestation of SARS-CoV-2 brain infection in some patients, without systemic or multiple organ failure symptoms. A small number of studies demonstrated that neuropsychiatric symptoms associated with COVID-19, initially presenting as a confused state, may subsequently evolve in a way that is consistent with the patients' neuropsychiatric history. A literature analysis on this topic prevalently showed case reports and case series of patients presenting delirium or delirium-like symptoms as the main outburst of COVID-19, plus a cognitive impairment, from mild to severe, which pre-existed or was demonstrated during the acute phase or after infection. Dementia appeared as one of the most frequent predisposing factors to SARS-CoV-2 infection complicated with delirium. Instead, contrasting data emerged on the potential link between COVID-19 and delirium in patients with cognitive impairment and without a neuropsychiatric history. Therefore, clinicians should contemplate the possibility that COVID-19 appears as delirium followed by a psychiatric exacerbation, even without other systemic symptoms. In addition, cognitive impairment might act as a predisposing factor for COVID-19 in patients with delirium.

Mechanism of Anosmia Caused by Symptoms of COVID-19 and Emerging Treatments

The occurrence of anosmia, the loss or change in sense of smell, is one of the most common symptoms of COVID-19 experienced by almost 53% of those affected. Several hypotheses explain the mechanism of anosmia in patients suffering from COVID-19. This study aims to review the related mechanisms and answer the questions regarding COVID-19-related anosmia as well as propose a new strategy for treatment of long-term anosmia as a result of COVID-19 infection. This paper covers all of the studies investigating olfactory disorders following COVID-19 infection and explains the possible reasons for the correlated anosmia, including olfactory cleft syndrome, local inflammation in the nasal epithelium, early apoptosis of olfactory cells, changes in olfactory cilia and odor transmission, damage to microglial cells, effect on olfactory bulbs, epithelial olfactory injury, and impairment of olfactory neurons and stem cells. The key questions that arise in this field have been discussed, such as why prevalent anosmia is varied among the age categories and among sexes and the correlation of anosmia with mild or severe COVID-19 infection. The angiotensin-converting enzyme 2 receptor is a significant player in the mechanism of anosmia in COVID-19 patients. Based on current studies, a novel approach to treat long-COVID-19 with ongoing anosmia has been proposed. The fields of smart drug delivery, tissue engineering, and cell therapy provide a hypothesized strategy that can minimize the side effects of current treatments and support efficient recovery of the olfactory system.

The Common Neurological Presentations and Clinical Outcomes of Coronavirus Disease 2019 in Saudi Arabia

Background: Neurological manifestations have increasingly become recognized in COVID-19. People from different ethnic backgrounds are experiencing different outcomes related to SARS-CoV-2 infection. Several cohort studies reported the common neurological manifestations and complications associated with COVID-19 disease around the world however, the prevalence of neurological complications associated with SARS-CoV-2 infection in the Arab countries and Saudi Arabia is still unknown.

Objective: To study the prevalence, risk factors, and characteristics of the neurological complications associated with COVID-19 and their relationship with clinical outcomes.

Methods: We conducted a prospective, single-center, observational, cohort study of consecutive hospitalized adults COVID-19 patients with and without neurological manifestation admitted between March 2020 until the end of December 2020. Data was collected prospectively using electronic medical records; Cases and controls were observed until they either get discharged from the hospital or died. The primary outcomes were death, survival, and survival with sequalae.

Results: Among 497 patients with COVID-19, 118 patients (23.7%) had neurological complications, 94 patients (18.9%) had encephalopathy, and 16 patients (3.2%) had cerebrovascular accidents (CVA). Patients with COVID-19-related neurological complications were older and more likely to have a pre-existing neurological disease. The most common neurological syndrome associated with COVID-19 were encephalopathy (18.9%) and headache (13.7%). Pre-existing neurological disease and an elevated neutrophil count were the strongest predictors of developing any neurological complications. Death form COVID-19 was associated with age (OR 1.06, 95% CI 1.02–1.10, P = 0.001), invasive ventilation (OR 37.12, 95% CI 13.36–103.14), COVID-19-related-neurological complications (OR 3.24, 95% CI 1.28–8.21, P = 0.01), and elevated CRP level (OR 1.01, 95% CI 1.00–1.01, P = 0.01).

Conclusions: COVID-19 is associated with a wide range of neurological manifestations in people living in Saudi Arabia, with older individuals and those with underlying neurological disorders being most at risk. The presence of neurological complications was associated with increased mortality and poor outcomes.

COVID-19 outcomes of 10,881 patients: retrospective study of neurological symptoms and associated manifestations (Philippine CORONA Study)

Our study aimed to determine the effects of new-onset neurological symptoms (NNS) on clinically relevant outcomes in hospitalized patients with COVID-19 infection. We conducted a nationwide, comparative, retrospective, cohort study among adult, hospitalized COVID-19 patients involving 37 hospital sites from various regions in the Philippines. We included a total of 10,881 patients with confirmed COVID-19 infection (2008 had NNS while 8873 did not have NNS). The adjusted hazard ratios (aHRs) for mortality among the mild and severe cases were significantly higher by 1.660 (95% CI 1.132–2.435) and by 1.352 (95% CI 1.042–1.752), respectively, in the NNS group compared to those in the non-NNS group. The aHRs for respiratory failure in the NNS group were significantly increased by 1.914 (95% CI 1.346–2.722), by 1.614 (95% CI 1.260–2.068), and by 1.234 (95% CI 1.089–1.398) among the mild, severe, and critical cases, respectively. The aHRs for ICU admission in the NNS group were still significantly higher by 1.973 (95% CI 1.457–2.673) and by 1.831 (95% CI 1.506–2.226) among the mild and severe cases, respectively. Patients who had NNS were not significantly associated with a longer duration of ventilator dependence (adjusted odds ratio (aOR) 0.954, 95% CI 0.772–1.179), longer ICU stay (aOR 0.983, 95% CI 0.772–1.252) and longer hospital admission (aOR 1.045, 95% CI 0.947–1.153). The presence of NNS significantly increases the risk of mortality, respiratory failure and ICU admission among COVID-19 patients. Registration and associated protocol publication: ClinicalTrials.gov website (NCT04386083); Espiritu AI, Sy MCC, Anlacan VMM, Jamora RDG. The Philippine COVID-19 Outcomes: a Retrospective study Of Neurological manifestations and Associated symptoms (The Philippine CORONA study): a protocol study. BMJ Open. 2020;10:e040944.

What can the neurological manifestations of COVID-19 tell us: a meta-analysis

Background

Covid-19 became a global pandemic in 2019. Studies have shown that coronavirus can cause neurological symptoms, but clinical studies on its neurological symptoms are limited. In this meta-analysis, we aimed to summarize the various neurological manifestations that occurred in COVID-19 patients and calculate the incidence of various neurological manifestations. At the same time, we further explored the mechanism of nervous system injury and prognosis in COVID-19 patients in combination with their nervous system manifestations. This study provides a reference for early clinical identification of COVID-19 nervous system injury in the future, so as to achieve early treatment and reduce neurological sequelae.

Methods

We systematically searched all published English literature related to the neurological manifestations of COVID-19 from January 1, 2020, to April 30, 2021, in Pubmed, Embase, and Cochrane Library. The keywords used were COVID-19 and terminology related to the nervous system performance. All included studies were selected by two independent reviewers using EndNote and NoteExpress software, any disagreement was resolved by consensus or by a third reviewer, and the selected data were then collected for meta-analysis using a random-effects model.

Results

A total of 168 articles (n = 292,693) were included in the study, and the meta-analysis showed that the most common neurological manifestations of COVID-19 were myalgia(33%; 95%CI 0.30–0.37; I² = 99.17%), smell impairment(33%; 95%CI 0.28–0.38; I² = 99.40%), taste dysfunction(33%; 95%CI 0.27–0.39; I² = 99.09%), altered mental status(32%; 95%CI 0.22–0.43; I² = 99.06%), headache(29%; 95%CI 0.25–0.33; I² = 99.42%), encephalopathy(26%; 95%CI 0.16–0.38; I² = 99.31%), alteration of consciousness(13%; 95%CI 0.08–0.19; I² = 98.10%), stroke(12%; 95%CI 0.08–0.16; I² = 98.95%), dizziness(10%; 95%CI 0.08–0.13; I² = 96.45%), vision impairment(6%; 95%CI 0.03–0.09; I² = 86.82%), intracerebral haemorrhage(5%; 95%CI 0.03–0.09; I² = 95.60%), seizure(4%; 95%CI 0.02 -0.05; I² = 98.15%), encephalitis(2%; 95%CI 0.01–0.03; I² = 90.36%), Guillan-Barré Syndrome (GBS) (1%; 95%CI 0.00–0.03; I² = 89.48%).

Conclusions

Neurological symptoms are common and varied in Covid-19 infections, and a growing number of reports suggest that the prevalence of neurological symptoms may be increasing. In the future, the role of COVID-19 neurological symptoms in the progression of COVID-19 should be further studied, and its pathogenesis and assessment methods should be explored, to detect and treat early neurological complications of COVID-19 and reduce mortality.

Posterior reversible encephalopathy syndrome during convalescence from COVID-19

Background and aim: With an ever-increasing population of patients recovering form severe coronavirus disease 2019 (COVID-19), recognizing long-standing and delayed neurologic manifestations is crucial. Here, we present a patient developing posterior reversible encephalopathy syndrome (PRES) in the convalescence form severe coronavirus disease 2019 (COVID-19).Case presentation: A 61-year-old woman with severe (COVID-19) confirmed by nasopharyngeal real-time reverse transcription-polymerase chain reaction (RT-PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) required invasive mechanical ventilation 24-hours after admission. During her intensive care unit stay, she developed transient acute kidney injury and septic shock. She was extubated after 22 days. On day 25, she developed generalized tonic-clonic seizures. Magnetic resonance imaging (MRI) of the brain showed bilateral subcortical lesions on the parietal and occipital lobes and multiple micro-and macro-bleeds, consistent with PRES. At this point, RT-PCR for SARS-CoV-2 in a respiratory specimen and cerebrospinal fluid was negative. She was discharged home 35 days after admission on oral levetiracetam. Control MRI five months after discharge showed bilateral focal gliosis. On follow-up, she remains seizure-free on levetiracetam.Conclusions: PRES has been observed before as a neurological manifestation of acute COVID-19; to our knowledge, this is the first PRES case occurring in a hospitalized patient already recovered from COVID-19. A persistent proinflammatory/prothrombotic state triggered by SARS-CoV-2 infection may lead to long-standing endothelial dysfunction, resulting in delayed PRES in patients recovering from COVID-19. With a rapid and exponential increase in survivors of acute COVID-19, clinicians should be aware of delayed (post-acute) neurological damage, including PRES.

Characteristics and predictors for silent hypoxemia in a cohort of hospitalized COVID-19 patients

Background

An intriguing feature recently unveiled in some COVID-19 patients is the “silent hypoxemia” phenomenon, which refers to the discrepancy of subjective well-being sensation while suffering hypoxia, manifested as the absence of dyspnea.

Objective

To describe the clinical characteristics and predictors of silent hypoxemia in hospitalized COVID-19 patients.

Methods

We conducted a prospective cohort study including consecutive hospitalized adult (≥ 18 years) patients with confirmed COVID-19 presenting to the emergency department with oxygen saturation (SpO2) ≤ 80% on room air from March 15 to June 30, 2020. We analyzed the characteristics, disease severity, and in-hospital outcomes of patients presenting with dyspnea and those without dyspnea (silent hypoxemia).

Results

We studied 470 cases (64.4% men; median age 55 years, interquartile range 46–64). There were 447 (95.1%) patients with dyspnea and 23 (4.9%) with silent hypoxemia. The demographic and clinical characteristics, comorbidities, laboratory and imaging findings, disease severity, and outcomes were similar between groups. Higher breathing and heart rates correlated significantly with lower SpO₂ in patients with dyspnea but not in those with silent hypoxemia. Independent predictors of silent hypoxemia were the presence of new-onset headache (OR 2.919, 95% CI 1.101–7.742; P = 0.031) and presenting to the emergency department within the first eight days after symptoms onset (OR 3.183, 95% CI 1.024–9.89; P = 0.045).

Conclusions

Patients with silent hypoxemia sought medical attention earlier and had new-onset headache more often. They were also likely to display lower hemodynamic compensatory responses to hypoxemia, which may underestimate the disease severity.