Olfactory and gustatory dysfunctions as a clinical presentation of mild-to-moderate forms of the coronavirus disease (COVID-19): a multicenter European study

Optimization of a panel of behavioral tests for use in containment using a golden Syrian hamster model

Golden Syrian hamsters are an often-overlooked model in behavioral testing. While previously utilized for research examining circadian rhythms and mammalian reproduction, they are less common than murine models in both infectious disease and behavioral studies. However, coronavirus disease-19 (COVID-19) quickly pushed hamster modeling to the forefront due to its myriad of advantages over mice in recapitulating human pathology and transmission. At least 10 % of COVID-19 survivors suffer from post-acute sequelae of COVID-19 (PASC), a collection of some 200 sequelae with neurologic sequelae (neuro-PASC) presenting with potentially debilitating symptomology. This presents a clear need for a small animal model that recapitulates human disease with the ability to assess any potential long term neurological changes. We adapted and optimized a panel of behavioral tests from previously accepted murine models utilizing the golden Syrian hamster model for use within biocontainment facilities. Our panel includes grip strength, Porsolt forced swim, and novel object recognition testing to measure muscle fatigue or weakness, depression, and memory loss or cognitive impairment, respectively. Apart from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), this panel of tests is applicable to other pathogens that cause neurologic sequelae, such as Nipah or eastern equine encephalitis viruses, or any other model systems that require the use of hamsters. In this manuscript, we detail the methods for each of these three behavioral tests, how to interpret and analyze the resulting data, and emphasize additional factors for consideration. We also provide baseline data for both male and female golden Syrian hamsters.

Assessment of two olfactory training methods for post-COVID-19 loss of olfaction: Classical and intensive

OBJECTIVES

To determine whether intensive olfactory training provides better chances of recovery than classic protocols in persistent dysosmia after Covid-19.

INTRODUCTION

In the literature, olfactory training holds pride of place in the management of post-infection olfactory disorder, with a classic 4-odor protocol. On the other hand, few studies have assessed the benefit of more intensive training.

MATERIALS AND METHODS

This prospective randomized clinical trial (No. 2020-A01397-32) assessed olfactory training for persistent dysosmia due to COVID-19, with 5 weeks' to 12 months' progression. Patients were divided between 2 groups, receiving a classical 4-odor protocol (n=49) or an intensive 8-odor protocol (n=30). Olfaction was assessed in consultation on the Sniffin' Sticks test, the DyNaChron self-reported olfaction questionnaire and a visual analogue scale (VAS), at inclusion (V1) and at 4 and 8 months (V2 and V3, respectively).

RESULTS

Both protocols significantly improved subjective olfactory assessment on VAS, with non-significant trends for improvement on psychophysical tests. There was no significant difference in olfactory recovery between the classic and intensive protocols. Adhesion to the training program decreased markedly beyond 4 months.

CONCLUSION

Intensive olfactory training did not increase the chances of olfactory recovery compared to the classic protocol in a population with persistent dysosmia following COVID-19 infection.

Socioecology and Prevalence of SARS-CoV-2 Infection in Quilombolas Living in the Brazilian Amazon

OBJECTIVES

This cross-sectional study presents socioecological, epidemiological aspects, and the seroprevalence of immunoglobulin G (IgG) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a group of quilombola (afro-derived) communities in the states of Pará and Tocantins, in the Brazilian Amazon, to evaluate the impact of SARS-CoV-2 prevalence among them.

METHODS

A total of 551 individuals participated. The detection of anti-SARS-CoV-2 antibodies was performed using an enzyme immunoassay. Socioeconomic and ecological data was collected from all participants 7 years of age or older who were not previously vaccinated.

RESULTS

The seroprevalence of antibodies in both states was 40.7% and was associated with factors such as age group, contact with infected individuals, and being in lockdown inside the quilombos. In Pará, a statistically significant association was observed between seroprevalence and females, and the age group of 12-18 years. In addition, seroprevalence in Pará was higher than in Tocantins, and the reported use of masks was a protective factor, while in Tocantins, the reported use of masks was associated with the presence of antibodies. There was no association between the prevalence of antibodies and the presence of COVID-19 symptoms in Pará. However, in Tocantins, diarrhea and loss of taste were associated with infection.

CONCLUSIONS

Quilombola are highly vulnerable groups due to the long history of enslavement in Brazil. This is the first investigation of SARS-CoV-2 seroprevalence and its impact in these groups in the Amazon. The study helps us to understand the relationship of socioecological differences, behavioral characteristics, and the dynamics of viral transmission associated with the risk of infection by SARS-CoV-2 among traditional populations, and can be useful to the planning of more culturally adequate public health policies for future epidemics.

Exploring the Relationship Between Obstructive Sleep Apnea and Olfactory Function

Obstructive sleep apnea (OSA) is increasingly recognized as a chronic condition that is closely interrelated to olfactory disorders, with a significant contribution to quality of health and overall quality of life. This narrative review aims to provide a thorough overview of the emerging evidence that now integrates these two previously considered distinct physiologic systems. Studies published recently have reported a significantly higher frequency of olfactory dysfunction among OSA patients compared to the general population, which raises the possibility of a causal relationship. We explore the postulated mechanisms behind this association, namely, the chronic intermittent hypoxia, local inflammatory effect, and neuroanatomical changes attributed to OSA. The review further explores the clinical impacts of this relationship through proposing the potential for an olfactory assessment to be used as a diagnostic modality for OSA and the effects of OSA treatment on olfactory function. Thus, we explore the difficulties in treating patients who experience both and suggest future areas for research. This review attempts to bridge the gap between the existing literature and impending investigation necessary for a better management of the interaction of sleep apnea and the human sense of smell.

Neurologic features in hospitalized patients with COVID-19: a prospective cohort in a catalan hospital

OBJECTIVES

To study the prevalence and timing of neurological manifestations, including cognitive involvement, in patients hospitalized for Coronavirus disease 2019 (COVID-19). To analyze the pathogenic mechanisms and any association they have with disease severity.

METHODS

Longitudinal cohort study with prospective follow-up of patients who required hospitalization. Patients under 65 who had no pre-existing cognitive impairment and did not require an ICU stay were evaluated 3 and 12 months after discharge using a battery of neuropsychological tests.

RESULTS

Of 205 patients hospitalized for COVID-19, 153 (74.6%) presented with neurological manifestations. The most frequent were myalgia (32.7%), headache (31.7%), dysgeusia (29.2%), and anosmia (24.9%). Patients with more severe illness at the time of hospitalization presented fewer neurological manifestations. Of the 62 patients who underwent neuropsychological examination 3 months after discharge, 22.6% had impaired attention, 19.4% impaired working memory, 16.1% impaired learning and retrieval, 9.7% impaired executive functions, and 8.2% impaired processing speed. Patients with anosmia also presented with more headache (OR 5.45; p < 0.001) and greater risk of working memory impairment (OR 5.87; p 0.03). At follow-up 12 months after hospital discharge, 14.3% of patients still showed impaired attention, 2.4% impaired working memory, 2.5% impaired executive functions, and 2.5% impaired processing speed.

DISCUSSION

Neurological manifestations are common in patients hospitalized for COVID-19 regardless of severity. The high prevalence of anosmia and its association with headache and working memory impairment at 3 months, suggest potential direct or indirect damage to the prefrontal cortex via invasion of the olfactory bulb by COVID-19.

Efficacy of the adjunctive use of photobiomodulation therapy in olfactory disorders in post-COVID-19 patients: A randomized controlled trial

OBJECTIVES

Photobiomodulation Therapy (PBMT) is a non-invasive treatment that uses photons from the red to infrared spectrum to modulate cellular processes with anti-inflammatory and regenerative properties. This study aimed to evaluate the use of PBMT applied intranasally in patients with an impaired sense of smell after COVID-19.

METHODS

This proof-of-concept study was a randomized, placebo-controlled clinical trial that recruited 81 patients with olfactory disorders after SARS-CoV-2 infection (1-12 months), randomly assigned to 3 groups: controls, red light and infrared light exposure groups. PBMT was applied twice a week for five weeks, associated with prednisolone 40 mg for five days and olfactory training for 90 days from the first day of laser application. UPSIT® and subjective chemosensory scores were the outcomes collected before the first session and three months thereafter.

RESULTS

Compared to controls, patients undergoing infrared PBMT showed more improvement in UPSIT® scores (+4.6 points, 95% CI: 1.5-7.8, p =  0.004) and a tendency towards reporting a better subjective smell score at the three-month follow-up. Response rates were 26.1% (95% CI: 6.7-45.5), 43.5% (95% CI: 21.6-65.4), and 68% (95% CI: 48.3-87.7) in the control, red and infrared groups, respectively. No major adverse events were reported.

CONCLUSION

Therapy with PBMT in the infrared frequency appears to be a safe option in treating post-COVID olfactory disorders when combined with a five-day use of systemic corticosteroid and 90 days of olfactory training.

LEVEL OF EVIDENCE: 2

Subjective smell and taste dysfunctions and prognosis in patients with COVID-19 admitted to a major public hospital in Southern Brazil: A retrospective cohort study (NUTRICOVID19)

The literature notes that coronavirus disease 2019 (COVID-19) patients with olfactory disturbances tend to have lower disease severity and that olfactory disturbances may act as a protective factor against mortality. So, this study aimed to explore the association of smell and/or taste disturbance with disease severity and all-cause mortality among patients who were hospitalized with COVID-19. A retrospective cohort study (Nutrition and COVID-19 Study [NUTRICOVID19]) was conducted with 1331 patients (men and women, age ≥ 18 years) hospitalized with COVID-19 between June and December 2020. Poisson and Cox regressions were used to investigate the unadjusted and adjusted associations between smell and/or taste disturbance and the following prognostic indicators: length of stay (LOS), intensive care unit admission, need for invasive mechanical ventilation (IMV), and mortality. Patients with altered smell and/or taste had a shorter LOS (9 vs 11 days), were less likely to require IMV (22% vs 35.1%), and experienced lower mortality (17.1% vs 29.2%) compared to those without such symptoms. After multivariable adjustment, patients with smell and/or taste disturbances were 33% less likely to need IMV compared to those without such symptoms (RR = 0.67; 95% CI = 0.50-0.88), but the relationship between these symptoms and mortality lost statistical significance. In this population of patients with COVID-19, the presence of smell and/or taste disturbances was associated to lower rates of IMV.

Unraveling Dysgeusia in SARS-CoV-2 Infection: Clinical and Laboratory Insights from Hospitalized COVID-19 Patients in Romania

Introduction: Dysgeusia has been regarded as a clinical feature associated with SARS-CoV-2 infection since the onset of the pandemic. The initial circulating variants were linked to the presence of dysgeusia; however, with the emergence of the Omicron variant, the incidence of dysgeusia has decreased. The aim of this study was to identify the incidence and characteristics of patients with dysgeusia from the onset of the pandemic to the Omicron variant. Methods: We conducted a retrospective study from March 2020 to December 2021, among adult patients hospitalized with COVID-19 in the main infectious diseases hospital in Romania. Clinical and laboratory data were collected and interpreted in relation to the presence or absence of dysgeusia. Results: The incidence of dysgeusia was 32.0%, with the majority of cases (44.2%) occurring in patients with the Beta SARS-CoV-2 variant. Dysgeusia has been predominantly observed in mild to moderate cases of the disease. The presence of obesity and hypertension has been shown to be negatively associated with the development of dysgeusia (OR = 0.45, OR = 0.39, respectively). In patients with dysgeusia, inflammatory changes such as lymphopenia were significantly less frequently identified (OR = 0.22, p < 0.001), as were increased C-reactive protein (OR = 0.12, p < 0.001) and increased interleukin-1 (OR = 0.42, p = 0.002), increased fibrinogen (OR = 0.31, p < 0.001), and increased ferritin (OR = 0.27, p < 0.001) compared to patients without dysgeusia. The incidence of acute respiratory failure was higher in the dysgeusia group (71.2% vs. 28.8%, p < 0.001). This was accompanied by a milder management of patients with dysgeusia and a median duration of hospitalization that was two days shorter. Conclusions: The presence or absence of dysgeusia in patients with COVID-19 appears to correlate with both the inflammatory response and outcome. In the context of evolving circulating viral variants, which seem to be associated with a lower incidence of dysgeusia, continuous monitoring of patients who develop this disorder remains essential to clarify the pathophysiologic mechanisms involved and to assess the potential of dysgeusia as a predictor of the course of SARS-CoV-2 infection.

Whole-body visualization of SARS-CoV-2 biodistribution in vivo by immunoPET imaging in non-human primates

The COVID-19 pandemic has caused at least 780 million cases globally. While available treatments and vaccines have reduced the mortality rate, spread and evolution of the virus are ongoing processes. Despite extensive research, the long-term impact of SARS-CoV-2 infection is still poorly understood and requires further investigation. Routine analysis provides limited access to the tissues of patients, necessitating alternative approaches to investigate viral dissemination in the organism. We address this issue by implementing a whole-body in vivo imaging strategy to longitudinally assess the biodistribution of SARS-CoV-2. We demonstrate in a COVID-19 non-human primate model that a single injection of radiolabeled [89Zr]COVA1-27-DFO human monoclonal antibody targeting a preserved epitope of the SARS-CoV-2 spike protein allows longitudinal tracking of the virus by positron emission tomography with computed tomography (PET/CT). Convalescent animals exhibit a persistent [89Zr]COVA1-27-DFO PET signal in the lungs, as well as in the brain, three months following infection. This imaging approach also allows viral detection in various organs, including the airways and kidneys, of exposed animals during the acute infection phase. Overall, the technology we developed offers a comprehensive assessment of SARS-CoV-2 distribution in vivo and provides a promising approach for the non-invasive study of long-COVID pathophysiology.

Single-cell transcriptomics reveals a compartmentalized antiviral interferon response in the nasal epithelium of mice

Type III interferons (IFNs) primarily act on epithelial cells and protect against virus infection of the mucosa, whereas type I IFNs act more systemically. To date, it has been unknown which epithelial subtypes in the upper airways, the primary site for initial infection for most respiratory viruses, primarily rely on type III IFN or type I IFNs for antiviral protection. To address this question, we performed a single-cell transcriptomics analysis of the epithelial IFN-mediated response focusing on the upper airways of mice. This work identified nine distinct cell types derived from the olfactory epithelium and thirteen distinct cell types from the respiratory epithelium. Interestingly, type I IFNs induced a stronger antiviral transcriptional response than type III IFN in respiratory epithelial cells, whereas in olfactory epithelial cells, including sustentacular (SUS) and Bowman's gland cells (BGC), type III IFN was more dominant compared to type I IFN. SUS and BGC, which provide structural support and maintain the integrity of olfactory sensory neurons, were highly susceptible to infection with a mouse-adapted variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 MA20) but were protected against infection if the animals were prophylactically treated with type III IFN. These findings demonstrate a high degree of cell type heterogeneity in terms of interferon-mediated antiviral responses and reveal a potent role for type III IFNs in protecting the olfactory epithelium.IMPORTANCESARS-CoV-2 infects SUS and BGC in the olfactory epithelium, causing an impairment of structural support and integrity of olfactory sensory neurons that can result in severe olfactory dysfunctions. We observed an unexpected compartmentalization of the IFN-mediated transcriptional response within the airway epithelium, and we found that olfactory epithelial cells preferentially respond to type III IFN, which resulted in robust antiviral protection of SUS and BGC. Given the proximity of the olfactory epithelium to the central nervous system, we hypothesize that evolution favored a type III IFN-biased antiviral immune response in this tissue to limit inflammatory responses in the brain. Cell type-specific antiviral responses in the upper airways, triggered by the different types of IFNs, should be investigated in more detail and carefully taken into consideration during the development of IFN-based antivirals for clinical use.

Knowledge mapping of Guillain-Barré syndrome from January 2013 to October 2023: A bibliometric analysis

BACKGROUND

With the COVID-19 pandemic and the serious sequelae, foreign factor-induced Guillain-Barré syndrome (GBS) has become a research focus in autoimmune peripheral neuropathies. The study employs a bibliometric system to illustrate the research hotspots and trends in GBS based on pertinent literature from January 2013 to October 2023.

METHODS

The Web of Science Core Collection retrieved articles on GBS from January 1, 2013, to October 28, 2023. These articles were then visualized and statistically evaluated using VOSviewer, CiteSpace software, R version 4.2.1, and Microsoft Office Excel 2019.

RESULTS

A total of 4269 articles on GBS were gathered. The United States of America produced the most publications (28.55%, 1219/4269), followed by China (14.22%, 607/4269). The world's leading country was the United States of America, with the most publications, the most substantial international cooperation, and the highest centrality (0.17). Union of French Research Universities (UDICE)-French Research Universities in France was the most productive organization (189 articles). Lancet was the highest cocited journal (2428), and Professor Jacobs, Bart C., was the most prolific author (93). The most significant increases were shown for the keywords coronavirus, respiratory failure, and coronavirus disease 2019. The novel coronavirus is an emerging virus that may cause GBS, indicating a promising area of research.

CONCLUSIONS

The study on GBS was illustrated using bibliometrics, and it covers trends in international collaboration, publications, and research hotspots. These findings allow the scientific community to pinpoint the novel ideas and directions that will drive future GBS research.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Coronavirus Disease 2019 Case Series in China: Sequelae and Effectiveness of Vaccination and Antiviral Drugs

Purpose of the Study

This study investigated post-coronavirus disease 2019 (COVID-19) sequelae among a sample of the Chinese population, and determined the statistical significance of correlations between age, sex, number of COVID-19 vaccinations, number of SARS-CoV-2 infections, development of pneumonia, use of specific drugs (namatevir/ritonavir, azvudine, molnupiravir), chronic underlying diseases, and post-COVID-19 sequelae.

Methods

Data from 869 patients, who visited the Emergency Department of Beijing Shijitan Hospital (Beijing, China) between December 7, 2022 to January 31, 2024, were collected. The criteria for admission: Age ≥ 14 years old, and diagnosed with ≥ 1 positive result on nucleic acid or antigen tests. Retrospectively analyzed the main manifestations of sequelae, statistical analysis of the relationship between age; sex; underlying diseases; number of COVID-19 vaccinations received; use of specific antiviral drugs for COVID-19 and prognosis, and statistical analyses, including logistic regression, were performed. Differences with P < 0.05 were considered to be statistically significant. Before entering the model, variables are screened using stepwise regression to ensure that the selected variables are the main ones related to the research question, thereby controlling for confounding factors. SPSS version 27 (IBM Corp. Armonk, NY, USA) was used for statistical analysis. In this study, the duration of sequelae ranged from 2 to 13 months.

Results and Conclusions

This study retrospectively analyzed 869 patients (415 male, 454 female), with an average age of 61.52 ± 23.09 years. There were 401 patients without underlying conditions and 468 patients with one or more underlying conditions. Regarding COVID-19 vaccination status, 320 patients were unvaccinated, while 576 patients received at least one dose of the COVID-19 vaccine. Additionally, 514 patients received antiviral medication, while 355 did not receive antiviral treatment. The primary manifestations of post-COVID-19 included shortness of breath, dizziness and weakness, chronic pneumonia, asthma, and reduced sense of smell. Individuals ≥ 70 years of age were more prone to COVID-19 pneumonia. Patients with underlying disease(s) exhibited statistically higher mortality rates after diagnosis of COVID-19. Vaccination against COVID-19 and the use of specific drugs had a statistically significant effect on mortality and the occurrence of post-COVID-19 sequelae. There was no statistically significant difference in COVID-19 infection rates between males and females, although males were more prone to COVID-19 pneumonia. Young women with COVID-19 often experienced no sequelae, and elderly males exhibited a high mortality rate.

Urine amino acid and gamma aminobutyric acid level in COVID 19 patients

Background and Objectives

SARS CoV2 has tropism for various tissues, including the respiratory tract, brain, endothelium, heart, kidney and liver. Neurological symptoms can also be seen in the clinical course of the disease, and anosmia is the most common. The main objective of our study was to examine the urinary amino acid profiles of moderately severe patients diagnosed with COVID-19 with a positive RT-PCR test and try to find metabolic changes associated with the infection. Also, it was aimed to investigate the neuroinhibitory Gamma-Aminobutyric acid (GABA) levels in order to examine the physiopathology.

Materials and Methods

Thirty adult cases who were followed up in the infection clinic with positive SARS CoV 2 RT-PCR and diagnosed with COVID 19 disease were included in the study with consent. The amino acid profile of these patients' urine samples, 30 different amino acid levels and creatine levels were examined using the liquid chromatography-mass spectrometry (LCMS) method on the SCIEX QTRAP 4500 device.

Results

The mean age of the patients is 40 ± 5. Elevated GABA in 28/30 cases, high hydroxylysine amino acid in 27/30 cases, low glycine in 30/30 cases were detected in the urine. The creatinine levels of the patients were found to be normal.

Conclusion

It has been thought that the height of GABA may be due to bacteria producing GABA as a result of the change in microbiota due to lactic acidosis, as well as that the virus may directly affect the brain and cause an increase in GABA.

Selected Acute Safety Events Following the Use of Nirmatrelvir/Ritonavir or Molnupiravir for COVID-19: A Nationwide Cohort Study in South Korea

There had been concerns about the acute complications during or shortly after coronavirus disease 2019 (COVID-19) treatment with nirmatrelvir/ritonavir (NMVr) and molnupiravir (MOL). This study aimed to compare the risks of selected acute safety events in patients treated with or without NMVr or MOL using the COVID-19 oral treatment safety assessment data, constructed through the linkage of nationwide databases: National COVID-19 registry, Real-time Prescription Surveillance, and National Health Insurance data. We identified all adults diagnosed with COVID-19 between January and November 2022, and then constructed two cohorts by matching up to four patients without antiviral treatment records to NMVr or MOL users using propensity score matching. Outcomes of interest were incident-selected cardiac (i.e., atrial fibrillation, other arrhythmia, bradycardia), neurological (i.e., seizure, neuropathy, encephalomyelitis), and miscellaneous (i.e., acute pancreatitis, acute liver injury, dysgeusia) events. A total of 739,935 NMVr users were matched with 2,951,690 comparators and 150,431 MOL users with 759,521 comparators. NMVr users were at lower risk for developing selected cardiac events (hazard ratio 0.74 [95% CI 0.65-0.87] for atrial fibrillation, 0.81 [0.65-0.99] for other arrhythmia, and 0.82 [0.70-0.96] for bradycardia) and dysgeusia (0.58 [0.45-0.74]). For MOL users, the risk was lower for atrial fibrillation (0.72 [0.53-0.96]) and dysgeusia (0.34 [0.18-0.65]). Overall, there were no increased risks of acute complications during and shortly after treatment with oral COVID-19 antivirals. Rather, the findings underscore their effectiveness in attenuating the risk of potential acute sequelae of COVID-19.

Executive functioning in subjects post COVID-19 infection in Mexico

Over the past three years, conflicting evidence has emerged regarding the impact of COVID-19 on executive functions and the frontal lobe. In this study, we evaluated executive functions in individuals from the state of Jalisco who had contracted COVID-19. Sixty individuals with a history of mild COVID-19 were included and compared to historical controls from the Mexican population, who had been assessed prior to the pandemic during the validation of the Trail Making Test Form B, the Stroop Color and Word Test, and the Modified Wisconsin Card Sorting Test (M-WCST). The post-infection group exhibited lower scores only on the M-WCST. Therefore, we concluded that individuals who have recovered from mild COVID-19 do not display widespread impairments in executive functions, with the exception of deficits observed on the M-WCST. This suggests possible neurophysiological alterations in the prefrontal cortex during SARS-CoV-2 infection, given that cognitive flexibility is primarily mediated in this region. These findings contribute to the growing body of evidence indicating that even non-hospitalized COVID-19 patients can experience executive function deficits, providing a foundation for further neurophysiological research into the mechanisms underlying this phenomenon.

Sleep and cardiorespiratory function assessed by a smart bed over 10 weeks post COVID-19 infection

Inadequate information exists regarding physiological changes post-COVID-19 infection. We used smart beds to record biometric data following COVID-19 infection in nonhospitalized patients. Recordings of daily biometric signals over 14 weeks in 59 COVID-positive participants' homes in 2020 were compared with the same participants' data from 2019. Participants completed a survey of demographic information, health conditions, COVID exposure and testing, and symptom prevalence/subjective severity. Mean age was 47.5 years (standard deviation [SD] 9.5), mean body mass index was 30.1 kg/m2 (SD 7.1), and 46% were men. During acute infection, 64% exhibited 5-6 h increased sleep duration, 51% had increased movement, and 64% had increased breathing rate (BR). Nearly 34% had paradoxical bradycardia (decreased heart rate by ~ 10 BPM concomitant with elevated BR and/or fever), with more-severe symptoms. Smart beds can detect physiological changes during COVID-19. A subtype of acute response (paradoxical bradycardia) may predict delay recovery from COVID-19.

Parosmia: Pathophysiology and Management

PURPOSE OF REVIEW

Parosmia is a qualitative olfactory disorder in which there is a mismatch between the memory of an odor and the actual experience triggered by an odor. There has been a surge in parosmia-related publications since the COVID-19 pandemic. This review summarizes the latest clinical findings, theories on pathophysiology and potential treatment options.

RECENT ADVANCES

Potential models of parosmia include peripheral or central hypotheses, which refer to aberrancies in olfactory neuron regeneration or information processing in central olfactory centers respectively. This leads to an incomplete or disorganized pattern of olfactory information relay. Studies using gas chromatography and functional magnetic resonance imaging have identified molecular triggers and intracranial functional connectivity patterns in parosmia respectively. Parosmia tends to occur in a delayed fashion after virus-induced anosmia. It may run a protracted course, but typically improves over time. Currently there are no generally approved, objective ways to ascertain the presence and measure the extent of parosmia. Evidence-based treatment for parosmia remains elusive. In some people, this can lead to health and quality of life issues.

Determinants of persistence and recovery of chronic coronavirus disease 2019 chemosensory dysfunction

BACKGROUND

In 2% to 4% of patients, coronavirus disease 2019 (COVID-19) chemosensory dysfunction (CSD) persists beyond 6 months, accounting for up to 4 million people in the United States. The predictors of persistence and recovery require further exploration.

OBJECTIVE

We sought to define the predictors of recovery and assess the quality of CSD in registry subjects with self-reported persistent smell and taste dysfunction after COVID-19.

METHODS

COVID-19 CSD participants (n = 408) from the 4 major waves of the pandemic completed questionnaires at 4 time points between 2021 and 2023, assessing demographics, sinonasal symptoms, and self-assessed recovery. Objective measurements of smell (UPSIT) and taste (BWETT) were performed on a subcohort (n = 108).

RESULTS

In this chronic CSD cohort, the average symptom duration was 24 ± 5 months, with 70% of those who contracted COVID-19 in 2020 report ongoing dysfunction. Phantosmia and dysgeusia were most prevalent in the early waves of COVID-19, while most participants reported disrupted ability to distinguish scents and flavors as well as undulating chemosensory function. Subjects reported low incidence of subjective sinonasal symptoms but high prevalence of sleep and mood disturbance. Cigarette smoke phantosmia was predictive of persistence of CSD. Conversely, self-reported environmental allergies and hypertension were predictive of recovery, and dust mite allergies specifically were negative predictors of cigarette smoke phantosmia. Finally, no treatment resolved CSD, but nasal steroids were reported to be effective by recovered CSD subjects. Objective measures of both smell and taste were significantly reduced in patients with chronic CSD compared to controls.

CONCLUSIONS

Chronic COVID-19 CSD is a syndrome resistant to standard anti-inflammatory therapy. Preexisting environmental allergies and hypertension predict recovery, while cigarette smoke phantosmia predicts persistence.

Essential Reads in Rhinology: A Bibliometric Analysis

Aims

Rhinology is a progressive subspecialty within otolaryngology. Bibliometric analysis is a powerful method to survey the landscape of literature on a specific topic and identify publication trends. We aimed to analyze the 50 most impactful English-language rhinology manuscripts of all time to create a targeted reading list for otolaryngologists.

Material and Methods

The Journal Citation Report within the Web of Science database was utilized to identify articles relating to rhinology. Web of Science Research categories were restricted to otolaryngology. The articles were then ranked by number of citations. The top 50 articles of all time ranked by number of citations were analyzed. The articles were analyzed for publication year, journal impact factor, citation density, first author (FA), and senior author (SA) name, country, and institution. Statistical analyses were performed.

Results

Most articles were published in the 2000s (N = 22, 44%) and 1990s (N = 11, 22%). Male FA (N = 37, 74%) and SA (N = 43, 86%) published most articles. Most articles were clinical studies (N = 36, 72%) followed by clinical guidelines/expert opinions. Most articles were published in the United States (N = 28, 56%) and England (N = 9, 18%). There were more female FAs of guidelines/position papers than basic lab, reviews, and clinical studies. England had more female FAs than other countries, and the United States had more female SA. There was an average of 585.2 citations per study.

Conclusion

This investigation highlights the most influential literature within rhinology. The most impactful studies are consensus statements, large multicenter studies, and technique studies. Significant gender disparities in authorship exist.

Brain Fog: a Narrative Review of the Most Common Mysterious Cognitive Disorder in COVID-19

It has been more than three years since COVID-19 impacted the lives of millions of people, many of whom suffer from long-term effects known as long-haulers. Notwithstanding multiorgan complaints in long-haulers, signs and symptoms associated with cognitive characteristics commonly known as "brain fog" occur in COVID patients over 50, women, obesity, and asthma at excessive. Brain fog is a set of symptoms that include cognitive impairment, inability to concentrate and multitask, and short-term and long-term memory loss. Of course, brain fog contributes to high levels of anxiety and stress, necessitating an empathetic response to this group of COVID patients. Although the etiology of brain fog in COVID-19 is currently unknown, regarding the mechanisms of pathogenesis, the following hypotheses exist: activation of astrocytes and microglia to release pro-inflammatory cytokines, aggregation of tau protein, and COVID-19 entry in the brain can trigger an autoimmune reaction. There are currently no specific tests to detect brain fog or any specific cognitive rehabilitation methods. However, a healthy lifestyle can help reduce symptoms to some extent, and symptom-based clinical management is also well suited to minimize brain fog side effects in COVID-19 patients. Therefore, this review discusses mechanisms of SARS-CoV-2 pathogenesis that may contribute to brain fog, as well as some approaches to providing therapies that may help COVID-19 patients avoid annoying brain fog symptoms.

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.

Neuropsychiatric Burden of SARS-CoV-2: A Review of Its Physiopathology, Underlying Mechanisms, and Management Strategies

The COVID-19 outbreak, caused by the SARS-CoV-2 virus, was linked to significant neurological and psychiatric manifestations. This review examines the physiopathological mechanisms underlying these neuropsychiatric outcomes and discusses current management strategies. Primarily a respiratory disease, COVID-19 frequently leads to neurological issues, including cephalalgia and migraines, loss of sensory perception, cerebrovascular accidents, and neurological impairment such as encephalopathy. Lasting neuropsychological effects have also been recorded in individuals following SARS-CoV-2 infection. These include anxiety, depression, and cognitive dysfunction, suggesting a lasting impact on mental health. The neuroinvasive potential of the virus, inflammatory responses, and the role of angiotensin-converting enzyme 2 (ACE2) in neuroinflammation are critical factors in neuropsychiatric COVID-19 manifestations. In addition, the review highlights the importance of monitoring biomarkers to assess Central Nervous System (CNS) involvement. Management strategies for these neuropsychiatric conditions include supportive therapy, antiepileptic drugs, antithrombotic therapy, and psychotropic drugs, emphasizing the need for a multidisciplinary approach. Understanding the long-term neuropsychiatric implications of COVID-19 is essential for developing effective treatment protocols and improving patient outcomes.

In-silico modeling of the interplay between APOE4, NLRP3, and ACE2-SPIKE complex in neurodegeneration between Alzheimer and SARS-CoV: implications for understanding pathogenesis and developing therapeutic strategies

The multifaceted interplay between neurodegenerative pathologies, including Alzheimer's disease (AD), and the highly virulent severe acute respiratory syndrome coronavirus (SARS-CoV), is implicated in various conditions. AD and SARS-CoV pathogenesis involve the APOE4 allele, NLRP3 inflammasome, and ACE2-SPIKE complex. APOE4, a genetic polymorphism of the APOE gene, is associated with an increased susceptibility to AD. NLRP3, an inflammatory protein of the innate immune system, plays a pivotal role in immune response cascades. In SARS-CoV, the ACE2 receptor serves as the principal portal for cellular entry, while APOE4 intricately interacts with the ACE2-spike protein complex, enhancing viral internalization process. The interaction of NLRP3 with the ACE2-spike protein complex leads to increased inflammatory signaling. The convergence of APOE4/NLRP3 and ACE2-spike protein complex interactions suggests a possible link between SARS and AD. Therefore, the current research centralizes the association between by utilizing SARS-CoV datasets to explore possible mechanisms that account for the pathogenesis of SARS-CoV and AD. The work is further extended to unveil the molecular interactions of APOE4 and NLRP3 with the ACE2-Spike protein complex at the molecular level by employing molecular dynamics simulation techniques. The therapeutic efficacy of Chyawanprash nutraceuticals is evaluated as their inhibitory potential towards APOE4-ACE2-Spike protein and NLRP3-ACE2-Spike protein complexes. Notably, our simulations unequivocally demonstrate the robust and enduring binding capability of the compound Phyllantidine with the target complexes throughout the simulation period. The findings of the studies further corroborate the primary hypothesis of APOE4 and NLRP3 as driver factors in the pathogenesis of both SARS-CoV and AD. Therefore, this research establishes a paradigm for comprehending the complex interaction between AD and SARS-CoV and lays the groundwork for further study in this domain.Communicated by Ramaswamy H. Sarma.

The long-term effect of COVID-19 infection on olfaction and taste; a prospective analysis

PURPOSE

To estimate long-term prognosis of chemosensory dysfunctions among patients recovering from COVID-19 disease.

METHODS

Between April 2020 and July 2022, we conducted a prospective, observational study enrolling 48 patients who experienced smell and/or taste dysfunction during the acute-phase of COVID-19. Patients were evaluated for chemosensory function up to 24 months after disease onset.

RESULTS

During the acute-phase of COVID-19, 80% of patients reported anosmia, 15% hyposmia, 63% ageusia, and 33% hypogeusia. At two years' follow-up, 53% still experienced smell impairment, and 42% suffered from taste impairment. Moreover, 63% of patients who reported parosmia remained with olfactory disturbance. Interestingly, we found a negative correlation between visual analogue scale scores for smell and taste impairments during the acute-phase of COVID-19 and the likelihood of long-term recovery.

CONCLUSION

Our study sheds light on the natural history and long-term follow-up of chemosensory dysfunction in patients recovering from COVID-19 disease. Most patients who initially suffered from smell and/or taste disturbance did not reach full recovery after 2 years follow-up. The severity of impairment may serve as a prognostic indicator for full recovery.

Oral complications during the two waves of COVID-19 pandemic in China: a prospective cross-section analysis of 510 cases using questionnaire

BACKGROUND

Oral complications such as parageusia, xerostomia, and oral ulcers are frequently observed in patients with COVID-19. The aim of this study was to understand the oral complications and their influencing factors during the two waves of the COVID-19 pandemic in China between December 2022 and May 2023.

METHODS

A total of 347 patients during the COVID-19 pandemic from December 2022 and January 2023 and 163 patients during the second COVID-19 pandemic were recruited through the Disease Prevention and Control Reporting System. Data on oral complications were collected via researcher-made questionnaires.

RESULTS

During both pandemic periods, more than 50% of the subjects developed oral complications. Specifically, the incidence of parageusia, pathological tongue coating, and xerostomia all exceeded 20%, while the incidence of oral ulcers surpassed 7%. Patients with allotriosmia and xerostomia had a significantly higher likelihood of developing other oral complications. Hospitalized patients requiring supplemental oxygen had a significantly higher incidence of oral complications.

CONCLUSIONS

The results of our study underline that oral complications during the COVID-19 pandemic are prevalent, and their incidence has not decreased during the subsequent pandemic. In the context of the ongoing global spread of COVID-19, this study lays the foundation for physicians in recognizing and managing oral complications, which will improve the oral health of communities globally.

SARS-CoV-2 Infection and the Neuroendocrine System

BACKGROUND

The novel coronavirus strain SARS-CoV-2 triggered the COVID-19 pandemic with severe economic and social ramifications. As the pathophysiology of SARS-CoV-2 infection in the respiratory system becomes more understood, growing evidence suggests that the virus also impacts the homeostasis-regulating neuroendocrine system, potentially affecting other organ systems.

SUMMARY

This review explores the interactions between SARS-CoV-2 and the neuroendocrine system, highlighting the effect of this virus on various endocrine glands, including the brain, hypothalamus, pituitary, pineal, thyroid, parathyroid, adrenal glands, pancreatic islets, gonads, and adipose tissue. The viral invasion disrupts normal hormonal pathways, leading to a range of endocrine disorders, immune dysregulation, and metabolic disturbances.

KEY MESSAGES

There is potential for SARS-CoV-2 to induce autoimmune responses, exacerbate existing endocrine conditions, and trigger new-onset disorders. Understanding these interactions is crucial for developing treatment strategies that address not only the respiratory symptoms of COVID-19 but also its endocrine complications. The review emphasizes the need for further research to elucidate the long-term effects of SARS-CoV-2 on endocrine health.

Comparative analyses of post-infectious olfactory dysfunction between COVID-19 and non-COVID-19 cases

To identify the differences between COVID-19-associated and non-COVID-19-associated olfactory dysfunction (OD), we analyzed demographic and clinical characteristics based on the causative virus (COVID versus non-COVID groups) in patients with post-infectious olfactory dysfunction (PIOD) who underwent the olfactory questionnaire and olfactory function test. Out of 169 patients with PIOD, 99 were diagnosed with COVID-19 (COVID group), while 70 were not (non-COVID group). The COVID group was younger and had a higher percentage of male patients as well as patients with parosmia than the non-COVID group. In the initial olfactory function tests, the TDI, discrimination and identification scores were significantly higher in the COVID group than in the non-COVID group. TDI scores were significantly increased in patients with PIOD after treatment, regardless of the group. The threshold score was significantly increased by 1.38 in the COVID group while the identification score was significantly increased by 2.67 in the non-COVID group. Patients with COVID-19-associated OD were younger in age, tended to be male, had a higher incidence of parosmia, and had better initial olfactory function test results compared to those with non-COVID-19-associated OD. Following treatment, odor detection threshold improved in the COVID group, whereas odor identification improved in the non-COVID group.

Factors associated with loss and recovery of smell and taste after COVID-19 infection

Objective

To identify predictors associated with loss and recovery of smell and taste after COVID-19 infection.

Methods

The Integrated Public Use Microdata Series (IPUMS) 2021 National Health Interview Series (NHIS) database was used to analyze factors associated with loss and recovery of smell and taste in respondents who had a previous COVID-19 infection. Significant variables from univariate analysis were included in a stepwise backward regression model to identify independent predictors.

Results

Of the 3844 individuals who answered yes to having contracted COVID-19, 51.1% and 48.9% reported losing smell and taste, respectively. 95.7% recovered smell and 97% recovered taste. Predictors associated with higher odds of reporting a loss of smell included younger age (odds ratio [OR] 0.98; 95% confidence interval [CI] 0.98-0.99), female sex (OR 1.38; CI 1.17-1.63), use of e-cigarettes (OR 1.59; CI 1.25-2.02), and Mexican ethnicity (OR 1.61; CI 1.22-2.11). Predictors of taste loss were younger age (OR 0.98; CI 0.98-0.99), female sex (OR 1.31; CI 1.08-1.58), and higher BMI (OR 1.02; CI 1.00-1.04). Female sex was associated with decreased odds of reporting a recovery of smell (OR 0.74; CI 0.59-0.92) and taste (OR 0.54; CI 0.42-0.69). Black/African American race (OR 1.44; CI 1.03-2.03) and non-Mexican Hispanic ethnicities (OR 1.55; CI 1.02-2.34) were associated with an increased likelihood of reporting the recovery of smell.

Conclusion

Various factors may be associated with the loss and recovery of smell and taste after COVID-19 infections. Clinicians may use this information to better counsel patients with these symptoms.

Level of evidence

4.

The Effect of Coronavirus Disease 2019 and Other Emerging Infections on Dentistry

The appearance of coronavirus disease 2019 (COVID-19) and other emerging infections has significantly impacted the field of dentistry, leading to widespread changes in practices and protocols. This has included the implementation of strict infection control measures, such as meticulous use of personal protective equipment, minimizing aerosol-generating procedures, and the adoption of teledentistry to reduce in-person contact. To date, the complete impact of delays in dental care caused by lockdowns has yet to be determined. The challenges faced during the COVID-19 pandemic have propelled innovation, shaping a new era of dentistry focused on safety against novel and re-emerging infections.

Treatments for Olfactory Dysfunction in COVID-19: A Systematic Review

Introduction  Olfactory dysfunction (OD) has emerged as a notable symptom among coronavirus disease 2019 (COVID-19) patients, with its prevalence varying among different populations. Recognizing the need to provide therapeutic solutions for these individuals, the present study seeks to comprehensively review the current evidence on potential underlying mechanisms and treatment modalities to manage OD in COVID-19 patients. Objective  To review the recent evidence on treatments for OD in COVID-19. From the beginning of the study until August 2nd, 2023, we conducted a systematic search on four electronic databases, PubMed, Scopus, Embase, and Web of Science, to find relevant publications. Data Synthesis  In the present study, 37 articles were selected for data extraction and included in the final review. The total number of patients was of 3,560 (2,098 female and 1,462 male subjects). The predominant disorders reported were hyposmia, anosmia, and parosmia. In most of the studies, the pre and postintervention assessments were the same, except for one study, in which the pre-intervention assessment of the disorder was through the SST, Sniffin' Sticks Test (SST), and the post-intervention assessment was through the Visual Analog Scale (VAS) and the 22-item Sinonasal Outcome Test (SNOT-22). The findings suggest olfactory training (OT), ivermectin, palmitoylethanolamide, luteolin, and systemic corticosteroids, in combination with topical corticosteroids, are potential therapies for COVID-19 patients with olfactory impairment. Conclusion  Although the review suggested several medications for OD treatment, further research must delve into the specific impact of OT, a non-pharmacological modality, regarding the mitigation of OD. By continuing to investigate and refine these therapeutic approaches, we can better support COVID-19 patients and improve their quality of life while navigating the challenges posed by OD.

Impact of Nutritional Status on COVID-19-Induced Olfactory Dysfunction

OBJECTIVE

Although olfactory dysfunction is one of the most common presenting signs of COVID-19 infection, little is known about which populations are most susceptible. The aim of this study is to evaluate the risk of COVID-19-induced chemosensory dysfunction in malnourished individuals.

METHODS

The N3C database was queried for adults having positive COVID-19 test result, diagnosis of chemosensory dysfunction within 2 weeks of positive test date, and overnutrition or undernutrition (i.e., deficiency or excess of micro- and macronutrients) related diagnoses prior to COVID-19 infection. Individuals previously diagnosed with chemosensory dysfunction were excluded. COVID-19-positive adults without olfactory dysfunction were similarly analyzed. Statistical analysis was performed using odds ratio calculations (95% confidence interval [CI]).

RESULTS

Of 3,971,536 patients with COVID-19, 73,211 adults were identified with a diagnosis of undernutrition and 428,747 adults were identified with a diagnosis of overnutrition prior to infection. Of those with undernutrition, 264 (0.36%) individuals were identified with a diagnosis of olfactory dysfunction within 2 weeks of infection. Of those with overnutrition, 2851 (0.66%) individuals were identified with a diagnosis of olfactory dysfunction within 2 weeks of infection. The calculated odds ratio for undernutrition and olfactory dysfunction was 0.731 (p < 0.0001, 95% CI [0.0647, 0.0825]). The calculated odds ratio for overnutrition and olfactory dysfunction was 1.419 (p < 0.0001, 95% CI [1.3359, 1.5081]).

CONCLUSION

Overnutrition may increase the risk of COVID-19-related olfactory dysfunction, while undernutrition may slightly protect. While reasons are unclear, baseline differences in metabolic, inflammatory, and structural biochemistry deserve closer inspection.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:4338-4343, 2024.

Clinical presentations, systemic inflammation response and ANDC scores in hospitalized patients with COVID-19

The association of anosmia/ageusia with a positive severe respiratory syndrome coronavirus 2 (SARS-CoV-2) test is well-established, suggesting these symptoms are reliable indicators of coronavirus disease 2019 (COVID-19) infection. This study investigates the clinical characteristics and systemic inflammatory markers in hospitalized COVID-19 patients in Taiwan, focusing on those with anosmia/ageusia. We conducted a retrospective observational study on 231 hospitalized COVID-19 patients (alpha variant) from April to July 2021. Clinical symptoms, dyspnea grading, and laboratory investigations, including neutrophil-lymphocyte ratios (NLRs), platelet-lymphocyte ratios (PLRs), and ANDC scores (an early warning score), were analyzed. Cough (64.1%), fever (58.9%), and dyspnea (56.3%) were the most common symptoms, while anosmia/ageusia affected 9% of patients. Those with anosmia/ageusia were younger, had lower BMI, lower systemic inflammatory markers, and better ANDC scores than those without these symptoms. Female patients exhibited lower NLR values and ANDC scores compared to male patients (all p < 0.05). Multivariable regression analysis demonstrated significant associations between NLR and CRP and ferritin levels (all p < 0.01), and between PLR and ESR and ferritin levels (p < 0.01). Categorized ANDC scores significantly correlated with the total hospital length of stay (all p < 0.05). Despite ethnic differences in the prevalence of anosmia/ageusia, our study highlights similar clinical presentations and inflammatory profiles to those observed in Western countries. The ANDC score effectively predicted hospital stay duration. These findings suggest that anosmia/ageusia may be associated with less severe disease and a lower inflammatory response, particularly in younger and female patients. The ANDC score can serve as a valuable prognostic tool in assessing the severity and expected hospital stay of COVID-19 patients.

Retinal and Corneal OCT Results of Patients Hospitalized and Treated in the Acute Phase of COVID-19

Objective: This study aimed to assess changes in the morphology of the retina and cornea in patients treated and hospitalized during the acute active phase of SARS-CoV-2 infection. Methods: A total of 24 patients with symptomatic early COVID-19 disease and 38 healthy participants from a control group were enrolled in our study. Among them, 20 received oxygen therapy at flow rates ranging from 1-10 L, while four received high-flow intranasal oxygen therapy (HFNOT). Some patients were treated with other types of therapy, such as Remdesivir, COVID-19 convalescent plasma therapy, or Tocilizumab. In the study, we focused on the analysis of optical coherence tomography (OCT) images of the cornea and retina including corneal thickness, central retinal thickness, retinal nerve fiber layer (RNFL), and optic disc parameters. The measurements were acquired using Spectral-domain OCT REVO FC 130. Results: The analysis did not show significant changes between the examined ophthalmological parameters before and after therapy. Furthermore, there were no detected significant differences between the tested parameters of the retina and cornea in COVID-19-positive patients compared to the control group. Conclusions: No ophthalmological manifestations of COVID-19 disease were observed during the study. Taking into account the results of other publications, the lack of an unambiguous position on this topic requires further research.

Polyunsaturated Fatty Acids as Potential Treatments for COVID-19-Induced Anosmia

Some individuals with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) experience anosmia, or loss of smell. Although the prevalence of anosmia has decreased with the emergence of the Omicron variant, it remains a significant concern. This review examines the potential role of polyunsaturated fatty acids (PUFAs), particularly omega-3 PUFAs, in treating COVID-19-induced anosmia by focusing on the underlying mechanisms of the condition. Omega-3 PUFAs are known for their anti-inflammatory, neuroprotective, and neurotransmission-enhancing properties, which could potentially aid in olfactory recovery. However, study findings are inconsistent. For instance, a placebo-controlled randomized clinical trial found no significant effect of omega-3 PUFA supplementation on olfactory recovery in patients with COVID-19-induced anosmia. These mixed results highlight the limitations of existing research, including small sample sizes, lack of placebo controls, short follow-up periods, and combined treatments. Therefore, more rigorous, large-scale studies are urgently needed to definitively assess the therapeutic potential of omega-3 PUFAs for olfactory dysfunction. Further research is also crucial to explore the broader role of PUFAs in managing viral infections and promoting sensory recovery.

Assessment of olfactory recovery after COVID-19: cross-sectional study

OBJECTIVE

This study aimed to evaluate recovery patterns of olfactory dysfunction among recovered COVID-19 patients, both subjective and objective, and correlate this recovery to the severity of the disease.

METHODS

The study recruited 200 patients and assigned them to two equal groups, one of them was a control group. The olfactory function of the study group was assessed via subjective and objective methods at baseline and then monthly for three months, with changes in smell function reported at each visit. These patients underwent chemosensory testing using the Sniffin' Sticks test and completed the validated Arabic version of the Questionnaire of Olfactory Disorders-Negative Statements (QOD-NS).

RESULTS

Olfactory dysfunction occurred on the first day of COVID-19 symptoms in 37% of participants. Subjective reports suggested smell recovery in 55% after 3 months, but Sniffin' Sticks showed only 1% with normal function, indicating persistent deficits in others. This study revealed smell recovery for 93% of participants (median 14 days), with most (58%) recovering within 2 weeks. No significant links were found between demographics, COVID-smell loss timing, and recovery speed.

CONCLUSION

Three months after COVID-19, many patients perceive smell recovery, but objective tests reveal shockingly high rates of persistent dysfunction. Further follow-up with objective tests is vital to assess the true burden and potential long-term effects of smell loss.

Therapeutic effects of olfactory training and systemic vitamin A in patients with COVID-19-related olfactory dysfunction: a double-blinded randomized controlled clinical trial

OBJECTIVES

The new corona virus infection, has a wide range of clinical manifestations. Fever and cough are the most common symptoms. The olfactory function may be also affected with COVID-19. In this randomized clinical trial, we wanted to evaluate the therapeutic effect of olfactory training with and without oral vitamin A for COVID-19-related olfactory dysfunction.

METHODS

Patients answered to the standard Persian version of anosmia reporting tool and performed the quick smell test before and after 12 weeks and at the end of the 12 months follow up. The patients were randomly allocated to three groups; Group A treatment with olfactory training, Group B treatment with oral vitamin A and olfactory training, and Group C as control group which only underwent nasal irrigation twice a day. Patients were treated for 3 months and followed up for 12 months.

RESULTS

Totally 90 patients were included in three groups. After interventions, 76.9% of patients in Group A, 86.7% of patients in Group B, and 26.7% of patients in Group C completely improved. The average intervention time was statistically significant in relationship with the final olfactory status of the patients in the 12 months follow-up. The olfactory training has significantly improved the smell alteration at the end of 3- and 12- months follow-up in A and B groups.

CONCLUSION

A three-months olfactory training is effective for improvement of COVID-19-related olfactory dysfunction. Adding daily oral vitamin A to olfactory training did not lead to better results in improving olfactory dysfunction.

LEVEL OF EVIDENCE

Step 2 (Level 2*): Randomized trial.

Characteristics and Impact of Long COVID at a Neurology Clinic

INTRODUCTION

Long COVID can also lead to neurological sequelae that affect existing diseases. This study explored how COVID-19 infection affects neurological patients and the relationship between long COVID and exacerbating factors.

METHODS

This retrospective study was conducted on 85 patients with neurological diseases after COVID-19 at the Neurology Department, Inje University Busan Paik Hospital, Korea. The data were collected between August and October 2022. The patients had a medical history, including COVID-19 infection, and completed symptom questionnaires. A long COVID questionnaire consisting of 35 inquiries in 10 categories was completed. Anxiety, depression, fatigue, functional difficulties, QOL, and health status changes were assessed.

RESULTS

The analysis comprised 85 participants (age: 56.4 ± 15.2 years; 63.5% women). Of the categories, neurological symptoms (68.2%) were the most prevalent, followed by systemic symptoms (64.7%) and cardiopulmonary symptoms (56.5%). Anxiety, depression, and fatigue symptoms were reported by 36.5%, 34.1%, and 42.4% of the participants. Subjective neurological deterioration after COVID-19 was reported in 28 participants (28/81, 34.6%). Anxiety, depression, and fatigue were influenced by long COVID symptoms and the subjective deterioration of neurological conditions.

CONCLUSION

This study analyzed the long COVID symptoms in patients with preexisting neurological conditions and their impact on mental health and quality of life. One-third of the participants reported a subjective worsening of their preexisting neurological conditions. This study highlights the need for comprehensive follow-ups and a multidisciplinary approach for patients with neurological conditions and prolonged COVID-19 symptoms.

Machine learning predictive modeling of the persistence of post-Covid19 disorders: Loss of smell and taste as case studies

The worldwide health crisis triggered by the novel coronavirus (COVID-19) epidemic has resulted in an extensive variety of symptoms in people who have been infected, the most prevalent disorders of which are loss of smell and taste senses. In some patients, these disorders might occasionally last for several months and can strongly affect patients' quality of life. The COVID-19-related loss of taste and smell does not presently have a particular therapy. However, with the help of an early prediction of these disorders, healthcare providers can direct the patients to control these symptoms and prevent complications by following special procedures. The purpose of this research is to develop a machine learning (ML) model that can predict the occurrence and persistence of post-COVID-19-related loss of smell and taste abnormalities. In this study, we used our dataset to describe the symptoms, functioning, and disability of 413 verified COVID-19 patients. In order to prepare accurate classification models, we combined several ML algorithms, including logistic regression, k-nearest neighbors, support vector machine, random forest, extreme gradient boosting (XGBoost), and light gradient boosting machine (LightGBM). The accuracy of the loss of taste model was 91.5 % with an area-under-cure (AUC) of 0.94, and the accuracy of the loss of smell model was 95 % with an AUC of 0.97. Our proposed modelling framework can be utilized by hospitals experts to assess these post-COVID-19 disorders in the early stages, which supports the development of treatment strategies.

COVID-19 Incidence, Risk Factors, Impact, and Related Stigma Among a Cohort of Persons With HIV in Washington, DC

BACKGROUND

Studies on the incidence of COVID-19 among persons with HIV (PWHs) present varied results. Few studies have investigated the impact of COVID-19 infection on health and socioeconomic factors or COVID-19 stigma. We sought to measure the incidence and severity of COVID-19 infection among a cohort of PWHs, characterize associated risk factors and impact, and document perceptions of COVID-19-related stigma.

METHODS

Data for this cross-sectional study come from the COVID-19 survey of participants in the DC Cohort longitudinal study from October 30, 2020, through December 31, 2022. Survey results were linked to electronic health records, including HIV laboratory test results and COVID test results. We conducted analyses comparing demographic, socioeconomic, HIV measures, and stigma among those with and without self-reported COVID-19.

RESULTS

Of 1972 survey respondents, 17% self-reported COVID-19 infection, with the greatest incidence in the Omicron wave of the pandemic. We found statistically significant differences by age, employment status, essential worker status, education, and household income. Longer duration of HIV diagnosis was associated with greater incidence of COVID-19. PWHs who were overweight or obese had a greater incidence of COVID-19 compared with those who were not. Over 40% of PWHs with COVID-19 reported experiencing at least 1 form of COVID-19-related stigma.

CONCLUSION

We observed a high incidence of COVID-19 infection among PWHs in DC. Furthermore, a substantial proportion of PWHs with COVID-19 reported experiencing COVID-19-related stigma. These findings add to the existing literature on COVID-19 coinfection among PWHs and highlight the need for awareness and support for those experiencing COVID-19 stigma.

Emergency Presentations of Coronavirus Disease (COVID-19): A Review of the Literature and Radiologic Perspective

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the debilitating global pandemic known as Coronavirus disease (COVID-19). In this paper, we highlight the widespread manifestations and complications across disease systems. In addition, we present their relevant imaging findings to inform appropriate investigations and management in patients presenting to the Emergency Department with COVID-19 and its respective sequalae. Of note, we outline considerations for diagnosis of long COVID, an important medium to long term sequalae in patients with previous COVID-19 infections.

Neurological Complications of COVID-19: Unraveling the Pathophysiological Underpinnings and Therapeutic Implications

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease (COVID-19), induced a global pandemic with a diverse array of clinical manifestations. While the acute phase of the pandemic may be waning, the intricacies of COVID-19's impact on neurological health remain a crucial area of investigation. Early recognition of the spectrum of COVID-19 symptoms, ranging from mild fever and cough to life-threatening respiratory distress and multi-organ failure, underscored the significance of neurological complications, including anosmia, seizures, stroke, disorientation, encephalopathy, and paralysis. Notably, patients requiring intensive care unit (ICU) admission due to neurological challenges or due to them exhibiting neurological abnormalities in the ICU have shown increased mortality rates. COVID-19 can lead to a range of neurological complications such as anosmia, stroke, paralysis, cranial nerve deficits, encephalopathy, delirium, meningitis, seizures, etc., in affected patients. This review elucidates the burgeoning landscape of neurological sequelae associated with SARS-CoV-2 infection and explores the underlying neurobiological mechanisms driving these diverse manifestations. A meticulous examination of potential neuroinvasion routes by SARS-CoV-2 underscores the intricate interplay between the virus and the nervous system. Moreover, we dissect the diverse neurological manifestations emphasizing the necessity of a multifaceted approach to understanding the disease's neurological footprint. In addition to elucidating the pathophysiological underpinnings, this review surveys current therapeutic modalities and delineates prospective avenues for neuro-COVID research. By integrating epidemiological, clinical, and diagnostic parameters, we endeavor to foster a comprehensive analysis of the nexus between COVID-19 and neurological health, thereby laying the groundwork for targeted therapeutic interventions and long-term management strategies.

Maximizing Participation in Olfactory Training in a Sample with Post-COVID-19 Olfactory Loss

PURPOSE

This study aims to highlight the feasibility of an olfactory training program entirely monitored through online media in COVID-19 patients.

METHODS

Classic olfactory training was performed with a sample with olfactory loss due COVID-19 (n = 11). Participants were engaged on a weekly video call in order to improve adherence and collect information regarding the number of correct answers and the individuals' perception of olfactory function. The olfactory status after training was compared to two groups, one composed of participants who contracted COVID-19 but did not report olfactory loss (n = 11) and a sample composed of healthy participants (n = 11).

RESULTS

The experimental group showed improvements throughout the training period (TDI score on week 0 was 20.3 (5.6) and 24.6 (4.3) for week 12, and on week 24 was 25.4 (6.2) (F = 5.115, df = 2, 20, p = 0.016), and post hoc tests showed that participants significantly improved their TDI score in W12 compared to W0 (SMD = 0.869, p = 0.041) and in W24 compared to W0 (SMD = 0.859, p = 0.041). The experimental group showed lower scores when compared with both groups, and the no OT COVID-19 group showed lower scores than the healthy control group, even though they did not report olfactory alterations.

CONCLUSIONS

Findings suggest that the strategies applied to improve adherence were successful since 100% of the sample completed the training adherence, offering a valuable framework for future olfactory training studies.

Circuit dynamics of the olfactory pathway during olfactory learning

The olfactory system plays crucial roles in perceiving and interacting with their surroundings. Previous studies have deciphered basic odor perceptions, but how information processing in the olfactory system is associated with learning and memory is poorly understood. In this review, we summarize recent studies on the anatomy and functional dynamics of the mouse olfactory learning pathway, focusing on how neuronal circuits in the olfactory bulb (OB) and olfactory cortical areas integrate odor information in learning. We also highlight in vivo evidence for the role of the lateral entorhinal cortex (LEC) in olfactory learning. Altogether, these studies demonstrate that brain regions throughout the olfactory system are critically involved in forming and representing learned knowledge. The role of olfactory areas in learning and memory, and their susceptibility to dysfunction in neurodegenerative diseases, necessitate further research.

Impaired metal perception and regulation of associated human foliate papillae tongue transcriptome in long-COVID-19

Chemosensory impairment is an outstanding symptom of SARS-CoV-2 infections. We hypothesized that measured sensory impairments are accompanied by transcriptomic changes in the foliate papillae area of the tongue. Hospital personnel with known SARS-CoV-2 immunoglobulin G (IgG) status completed questionnaires on sensory perception (n = 158). A subcohort of n = 141 participated in forced choice taste tests, and n = 43 participants consented to donate tongue swabs of the foliate papillae area for whole transcriptome analysis. The study included four groups of participants differing in IgG levels (≥ 10 AU/mL = IgG+; < 10 AU/mL = IgG-) and self-reported sensory impairment (SSI±). IgG+ subjects not detecting metallic taste had higher IgG+ levels than IgG+ participants detecting iron gluconate (p = 0.03). Smell perception was the most impaired biological process in the transcriptome data from IgG+/SSI+ participants subjected to gene ontology enrichment. IgG+/SSI+ subjects demonstrated lower expression levels of 166 olfactory receptors (OR) and 9 taste associated receptors (TAS) of which OR1A2, OR2J2, OR1A1, OR5K1 and OR1G1, as well as TAS2R7 are linked to metallic perception. The question raised by this study is whether odorant receptors on the tongue (i) might play a role in metal sensation, and (ii) are potential targets for virus-initiated sensory impairments, which needs to be investigated in future functional studies.

Neuropsychological functioning and its correlates at 1 year follow-up of severe COVID-19

BACKGROUND

Short-term cognitive impairment is associated with SARS-CoV-2 infection but the long-term impact is yet to be examined in detail. We aim to study the evolution of these symptoms in severe COVID-19 patients admitted to the intensive care unit (ICU) between April and December 2020 1 year after hospital discharge and to analyze its clinical correlates.

METHOD

A total of 58 patients agreed to participate in the 6 months follow-up and 30 at 1 year after hospital discharge. Demographic, clinical and laboratory data were collected and a comprehensive neuropsychological battery including validated tests for the main cognitive domains was administered. To test the magnitude of neurocognitive sequelae, two standard deviations below normative group were considered. To compare the neuropsychological performance at 6 and 12 months follow-up we used repeated measures tests. Finally, regression analyses were performed to test the main effects of medical and psychological factors on multiple cognition.

RESULTS

Almost half of the sample continued to have impaired performance on neuropsychological tests at 12 months follow-up. In comparison with the results obtained at 6 months, significant improvements were found in immediate recall (d = 0.49), delayed recall (d = 0.45), and inhibitory control (d = 0.53). Medical variables predicted cognitive performance at 6 months but not at 12 months follow-up, while anxiety and depression predicted cognitive deficits in the long-term.

CONCLUSIONS

A generalised improvement was observed in severe COVID-19 patients at follow-up. This improvement was particularly notable in verbal memory and executive functioning. However, a considerable proportion of the sample continued to present deficits at 1 year follow-up.

Cognitive dysfunctions in the course of SARS‑CoV‑2 virus infection, including NeuroCOVID, frontal syndrome and cytokine storm (Review)

During the coronavirus disease 2019 (COVID-19) pandemic, cognitive impairment of varying degrees of severity began to be observed in a significant percentage of patients. The present study discussed the impact of immunological processes on structural and functional changes in the central nervous system and the related cognitive disorders. The purpose of the present review was to analyse and discuss available information from the scientific literature considering the possible relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral infection and cognitive impairment, including NeuroCOVID, frontal syndrome and cytokine storm. A systematic literature review was conducted using: Google Scholar, Elsevier and the PubMed database. When searching for materials, the following keywords were used: 'cognitive dysfunctions', 'SARS-CoV-2', 'COVID-19', 'Neuro-SARS2', 'NeuroCOVID', 'frontal syndrome', 'cytokine storm', 'Long COVID-19'. A total of 96 articles were included in the study. The analysis focused on the characteristics of each study's materials, methods, results and conclusions. SARS-CoV-2 infection may induce or influence existing cognitive disorders of various nature and severity. The influence of immunological factors related to the response against SARS-CoV-2 on the disturbance of cerebral perfusion, the functioning of nerve cells and the neuroprotective effect has been demonstrated. Particular importance is attached to the cytokine storm and the related difference between pro- and anti-inflammatory effects, oxidative stress, disturbances in the regulation of the hypothalamic-pituitary-adrenal axis and the stress response of the body.

A non-invasive AI-based system for precise grading of anosmia in COVID-19 using neuroimaging

COVID-19 (Coronavirus), an acute respiratory disorder, is caused by SARS-CoV-2 (coronavirus severe acute respiratory syndrome). The high prevalence of COVID-19 infection has drawn attention to a frequent illness symptom: olfactory and gustatory dysfunction. The primary purpose of this manuscript is to create a Computer-Assisted Diagnostic (CAD) system to determine whether a COVID-19 patient has normal, mild, or severe anosmia. To achieve this goal, we used fluid-attenuated inversion recovery (FLAIR) Magnetic Resonance Imaging (FLAIR-MRI) and Diffusion Tensor Imaging (DTI) to extract the appearance, morphological, and diffusivity markers from the olfactory nerve. The proposed system begins with the identification of the olfactory nerve, which is performed by a skilled expert or radiologist. It then proceeds to carry out the subsequent primary steps: (i) extract appearance markers (i.e.,1 s t and2 n d order markers), morphology/shape markers (i.e., spherical harmonics), and diffusivity markers (i.e., Fractional Anisotropy (FA) & Mean Diffusivity (MD)), (ii) apply markers fusion based on the integrated markers, and (iii) determine the decision and corresponding performance metrics based on the most-promising classifier. The current study is unusual in that it ensemble bags the learned and fine-tuned ML classifiers and diagnoses olfactory bulb (OB) anosmia using majority voting. In the 5-fold approach, it achieved an accuracy of 94.1%, a balanced accuracy (BAC) of 92.18%, precision of 91.6%, recall of 90.61%, specificity of 93.75%, F1 score of 89.82%, and Intersection over Union (IoU) of 82.62%. In the 10-fold approach, stacking continued to demonstrate impressive results with an accuracy of 94.43%, BAC of 93.0%, precision of 92.03%, recall of 91.39%, specificity of 94.61%, F1 score of 91.23%, and IoU of 84.56%. In the leave-one-subject-out (LOSO) approach, the model continues to exhibit notable outcomes, achieving an accuracy of 91.6%, BAC of 90.27%, precision of 88.55%, recall of 87.96%, specificity of 92.59%, F1 score of 87.94%, and IoU of 78.69%. These results indicate that stacking and majority voting are crucial components of the CAD system, contributing significantly to the overall performance improvements. The proposed technology can help doctors assess which patients need more intensive clinical care.

Lab results of COVID-19 patients: Omicron vs delta variants

BACKGROUND

The coronavirus disease 2019 (COVID-19) virus has been a world-known pandemic since February 2020. Multiple variances had been established; the most common variants in Israel were omicron and delta.

AIM

To analyze and compare laboratory values in the "omicron" and "delta" variants of the coronavirus by conducting follow-up examinations and laboratory audits on COVID-19 patients admitted to our institution.

METHODS

A retrospective study, two groups, 50 patients in each group. Patients examined positive for COVID-19 were divided into groups according to the common variant at the given time. We reviewed demographic data and laboratory results such as complete blood count and full chemistry, including electrolytes and coagulation parameters.

RESULTS

The mean age was 52%, 66.53 ± 21.7 were female. No significance was found comparing laboratory results in the following disciplines: Blood count, hemoglobin, and lymphocytes (P = 0.41, P = 0.87, P = 0.97). Omicron and delta variants have higher neutrophil counts, though they are not significantly different (P = 0.38). Coagulation tests: Activated paritial thromoplastin test and international normalized ratio (P = 0.72, P = 0.68). We found no significance of abnormality for all electrolytes.

CONCLUSION

The study compares laboratory results of blood tests between two variants of the COVID-19 virus - omicron and delta. We found no significance between the variants. Our results show the need for further research with larger data as well as the need to compare all COVID-19 variants.

[Dizziness and hearing loss in healthcare workers with COVID-19]

Coronavirus disease 2019 (COVID-19) affects the respiratory system. Studying the clinical characteristics of this infection has revealed its tropism to the nervous system, which is responsible for neurological and sensory damage, in particular, dizziness and hearing loss. To determine the frequency and characteristics of the neurological impairment represented by dizziness and hearing loss in healthcare professionals (HCP) with COVID-19. Cross-sectional descriptive study conducted among HCP at Charles Nicolle Hospital (CNH) in Tunis affected by COVID-19 during the period from September 2020 to December 2020. Data collection was carried out by regular telephone follow-up of COVID-19 symptoms in these HCPs during the period of sanitary isolation. A total of 482 HCPs with COVID-19 were collected. The average age of the population was 41 ± 10 years, of which 111 were men (23%) and 371 were women (77%). The main neurological manifestations were: headache (71.2%), anosmia (60%), dizziness (21.8%), and hearing loss (1.5%). Patients with vertigo were significantly older (P=0.035), female (P=0.003), obese (P=0.014), suffering from more comorbidities (P=0.004), and having greater professional seniority (P=0.009). Dizziness was significantly associated with fever (P=0.001), abdominal pain (P=0.001), and desaturation (P=0.039). Neurological symptoms including dizziness and hearing loss may be the only sign with which a case of COVID-19 could be recognized. Raising awareness of such a presentation of COVID-19 patients is crucial during this pandemic period to prevent infectious spread, especially in hospitals.