Anosmia and Ageusia as the Only Indicators of Coronavirus Disease 2019 (COVID-19)

Frequency and Severity of Ear-Nose-Throat (ENT) Symptoms during COVID-19 Infection

Background and Objectives: Coronavirus disease 2019 (COVID-19) is a new disease entity caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The main symptoms of infection at the onset of the pandemic include dyspnea, cough and high fever. Ear−nose−throat (ENT) symptoms are among the ones presented by patients in the course of infection. The aim of the study was to analyze the frequency of ENT symptoms and to assess their severity and duration in COVID-19 patients. Materials and Methods: The study included 337 patients who had been infected with SARS-CoV-2, as confirmed by a PCR test. The study participants were >18 years old; the mean age was 43.98 years ± 13.47 SD. The convalescents completed a questionnaire that contained 26 questions, including 9 detailed questions related to ENT symptoms, such as sore throat, vertigo, dizziness, hearing disorders, olfactory disorders, taste disturbance, headache, cough and dyspnea. The severity of symptoms was assessed using a Visual Analogue Scale (VAS). Results: The most reported ENT symptoms were olfactory disorders, which occurred in 72% of patients. The second most frequent symptom was taste disturbance (68%), VAS = 6.79 ± 3.01. Vertigo and dizziness were reported by 34% of respondents (VAS = 4.01 ± 2.01). Tinnitus was observed in 15% of patients, VAS = 3.87 ± 1.98; 14% of the subjects reported hearing impairment (VAS = 3.81 ± 2.37). Conclusions: Symptoms related to the sense of smell, taste and hearing are some of the most common symptoms in the course of COVID-19, which is important in the therapeutic and epidemiological management of patients. Delayed diagnosis and treatment of symptoms, especially those related to the hearing organ, may result in greater permanent damage.

Olfactory and gustatory disorders caused by COVID-19: How to regain the pleasure of eating?

Background

Recently, anosmia and ageusia (and their variations) have been reported as frequent symptoms of COVID-19. Olfactory and gustatory stimuli are essential in the perception and pleasure of eating. Disorders in sensory perception may influence appetite and the intake of necessary nutrients when recovering from COVID-19. In this short commentary, taste and smell disorders were reported and correlated for the first time with food science.

Scope and approach

The objective of this short commentary is to report that taste and smell disorders resulted from COVID-19 may impact eating pleasure and nutrition. It also points out important technologies and trends that can be considered and improved in future studies.

Key findings and conclusions

Firmer food textures can stimulate the trigeminal nerve, and more vibrant colors are able to increase the modulation of brain metabolism, stimulating pleasure. Allied to this, encapsulation technology enables the production of new food formulations, producing agonist and antagonist agents to trigger or block specific sensations. Therefore, opportunities and innovations in the food industry are wide and multidisciplinary discussions are needed.

AI-driven quantification of ground glass opacities in lungs of COVID-19 patients using 3D computed tomography imaging

Objectives

Ground-glass opacity (GGO)—a hazy, gray appearing density on computed tomography (CT) of lungs—is one of the hallmark features of SARS-CoV-2 in COVID-19 patients. This AI-driven study is focused on segmentation, morphology, and distribution patterns of GGOs.

Method

We use an AI-driven unsupervised machine learning approach called PointNet++ to detect and quantify GGOs in CT scans of COVID-19 patients and to assess the severity of the disease. We have conducted our study on the “MosMedData”, which contains CT lung scans of 1110 patients with or without COVID-19 infections. We quantify the morphologies of GGOs using Minkowski tensors and compute the abnormality score of individual regions of segmented lung and GGOs.

Results

PointNet++ detects GGOs with the highest evaluation accuracy (98%), average class accuracy (95%), and intersection over union (92%) using only a fraction of 3D data. On average, the shapes of GGOs in the COVID-19 datasets deviate from sphericity by 15% and anisotropies in GGOs are dominated by dipole and hexapole components. These anisotropies may help to quantitatively delineate GGOs of COVID-19 from other lung diseases.

Conclusion

The PointNet++ and the Minkowski tensor based morphological approach together with abnormality analysis will provide radiologists and clinicians with a valuable set of tools when interpreting CT lung scans of COVID-19 patients. Implementation would be particularly useful in countries severely devastated by COVID-19 such as India, where the number of cases has outstripped available resources creating delays or even breakdowns in patient care. This AI-driven approach synthesizes both the unique GGO distribution pattern and severity of the disease to allow for more efficient diagnosis, triaging and conservation of limited resources.

Magnetic Resonance Imaging Confirmed Olfactory Bulb Reduction in Long COVID-19: Literature Review and Case Series

An altered sense of smell and taste was recognized as one of the most characteristic symptoms of coronavirus infection disease (COVID-19). Despite most patients experiencing a complete functional resolution, there is a 21.3% prevalence of persistent alteration at 12 months after infection. To date, magnetic resonance imaging (MRI) findings in these patients have been variable and not clearly defined. We aimed to clarify radiological alterations of olfactory pathways in patients with long COVID-19 characterized by olfactory dysfunction. A comprehensive review of the English literature was performed by analyzing relevant papers about this topic. A case series was presented: all patients underwent complete otorhinolaryngology evaluation including the Sniffin’ Sticks battery test. A previous diagnosis of SARS-CoV-2 infection was confirmed by positive swabs. The MRIs were acquired using a 3.0T MR scanner with a standardized protocol for olfactory tract analysis. Images were first analysed by a dedicated neuroradiologist and subsequently reviewed and compared with the previous available MRIs. The review of the literature retrieved 25 studies; most cases of olfactory dysfunction more than 3 months after SARS-CoV-2 infection showed olfactory bulb (OB) reduction. Patients in the personal case series had asymmetry and a reduction in the volume of the OB. This evidence was strengthened by the comparison with a previous MRI, where the OBs were normal. The results preliminarily confirmed OB reduction in cases of long COVID-19 with an altered sense of smell. Further studies are needed to clarify the epidemiology, pathophysiology and prognosis.

COVID-19, Cation Dysmetabolism, Sialic Acid, CD147, ACE2, Viroporins, Hepcidin and Ferroptosis: A Possible Unifying Hypothesis

Background: iron and calcium dysmetabolism, with hyperferritinemia, hypoferremia, hypocalcemia and anemia have been documented in the majority of COVID-19 patients at later/worse stages. Furthermore, complementary to ACE2, both sialic acid (SA) molecules and CD147 proved relevant host receptors for SARS-CoV-2 entry, which explains the viral attack to multiple types of cells, including erythrocytes, endothelium and neural tissue. Several authors advocated that cell ferroptosis may be the core and final cell degenerative mechanism.

Methods: a literature research was performed in several scientific search engines, such as PubMed Central, Cochrane Library, Chemical Abstract Service. More than 500 articles were retrieved until mid-December 2021, to highlight the available evidence about the investigated issues.

Results: based on COVID-19 literature data, we have highlighted a few pathophysiological mechanisms, associated with virus-based cation dysmetabolism, multi-organ attack, mitochondria degeneration and ferroptosis. Our suggested elucidated pathological sequence is: a) spike protein subunit S1 docking with sialylated membrane glycoproteins/receptors (ACE2, CD147), and S2 subunit fusion with the lipid layer; b) cell membrane morpho-functional changes due to the consequent electro-chemical variations and viroporin action, which induce an altered ion channel function and intracellular cation accumulation; c) additional intracellular iron concentration due to a deregulated hepcidin-ferroportin axis, with higher hepcidin levels. Viral invasion may also affect erythrocytes/erythroid precursors, endothelial cells and macrophages, through SA and CD147 receptors, with relative hemoglobin and iron/calcium dysmetabolism. AB0 blood group, hemochromatosis, or environmental elements may represent possible factors which affect individual susceptibility to COVID-19.    

Conclusions: our literature analysis confirms the combined role of SA molecules, ACE2, CD147, viroporins and hepcidin in determining the cation dysmetabolism and final ferroptosis in the cells infected by SARS-CoV-2. The altered ion channels and electrochemical gradients of the cell membrane have a pivotal role in the virus entry and cell dysmetabolism, with subsequent multi-organ immune-inflammatory degeneration and erythrocyte/hemoglobin alterations.

Smell disorders associated with COVID-19 infection

Background

We performed a search in the PubMed databases, Web of Science, LILACS, MEDLINE, SciELO, and Cochrane Library using the keywords COVID-19, Novel coronavirus, corona, 2019-nCoV, SARS-CoV-2, ENT, nose, anosmia, hyposmia, smell, olfactory, ORL, different ENT related symptoms. We reviewed published and peer-reviewed studies that reported the ENT manifestations in COVID-19 laboratory-confirmed positive patients.

Main text

Within the included 2549 COVID-19 laboratory-confirmed positive patients, smell affection was reported in 1453 patients (57%). The other reported ENT manifestations were taste disorder (49.2%), headache (42.8%), nasal blockage (26.3%), sore throat (25.7%), runny nose or rhinorrhea (21.3%), upper respiratory tract infection (URTI) (7.9%), and frequent sneezing (3.6%).

Conclusion

Smell affection in COVID-19 is common and could be one of the red flag signs in COVID-19 infection. With a sensitivity of utilized questionnaire in smell identification, a homogenous universal well-defined COVID-19 questionnaire is needed to make the COVID-19 data collection more sensible.

The microvascular hypothesis underlying neurologic manifestations of long COVID-19 and possible therapeutic strategies

With the ongoing distribution of the coronavirus disease (COVID) vaccines, the pandemic of our age is ending, leaving the world to deal with its well-documented aftereffects. Long COVID comprises a variety of symptoms, of which the neurological component prevails. The most permeating theory on the genesis of these symptoms builds upon the development of microvascular dysfunction similar to that seen in numerous vascular diseases such as diabetes. This can occur through the peripheral activation of angiotensin-converting enzyme 2 receptors, or through exacerbations of pro-inflammatory cytokines that can remain in circulation even after the infection diminishes. Several drugs have been identified to act on the neurovascular unit to promote repair, such as gliptins, and others. They also succeeded in improving neurologic outcome in diabetic patients. The repurposing of such drugs for treatment of long COVID-19 can possibly shorten the time to recovery of long COVID-19 syndrome.

Olfactory and Taste Dysfunction in Coronavirus Disease 2019 Pandemic

This study is done to raise awareness of olfactory and taste dysfunction association in coronavirus disease, urging early detection and isolation of coronavirus positive patients thus breaking the chain of transmission of disease. This is a retrospective observational study done in outpatient department of tertiary care hospital in Mumbai, west India from 1st May 2020 to 1st August 2020 on patients who were confirmed positive for COVID-19 by real-time reverse transcription polymerase chain reaction (rRT-PCR) and having olfactory dysfunction and/or taste disorders. In study population, anosmia and ageusia occurred in 88% and 83.33% respectively. In control population, anosmia and ageusia occurred in 93% and 85.71% respectively. The mean duration of anosmia was around 2 weeks and 3 weeks for study and control group respectively. In study population 94.6% recovered from anosmia, whereas in control population 64.3% recovered from anosmia. Anosmia gradually improved to hyposmia. In the study population 94.3% hyposmia patients showed recovery, while in control population 85.2% showed recovery. Ageusia collaborated with the duration of anosmia. Recovery from taste dysfunction was 88.6% and 63.9% in study and control population respectively. Olfactory and taste dysfunction are very important clinical features of coronavirus positive patients with anosmia being the most prominent symptom. All patients presenting with smell and or taste dysfunction should be screened for coronavirus disease, helping in early detection in asymptomatic patients.

AI-DRIVEN QUANTIFICATION OF GROUND GLASS OPACITIES IN LUNGS OF COVID-19 PATIENTS USING 3D COMPUTED TOMOGRAPHY IMAGING

Objectives

Ground-glass opacity (GGO) - a hazy, gray appearing density on computed tomography (CT) of lungs - is one of the hallmark features of SARS-CoV-2 in COVID-19 patients. This AI-driven study is focused on segmentation, morphology, and distribution patterns of GGOs.

Method

We use an AI-driven unsupervised machine learning approach called PointNet++ to detect and quantify GGOs in CT scans of COVID-19 patients and to assess the severity of the disease. We have conducted our study on the "MosMedData", which contains CT lung scans of 1110 patients with or without COVID-19 infections. We quantify the morphologies of GGOs using Minkowski tensors and compute the abnormality score of individual regions of segmented lung and GGOs.

Results

PointNet++ detects GGOs with the highest evaluation accuracy (98%), average class accuracy (95%), and intersection over union (92%) using only a fraction of 3D data. On average, the shapes of GGOs in the COVID-19 datasets deviate from sphericity by 15% and anisotropies in GGOs are dominated by dipole and hexapole components. These anisotropies may help to quantitatively delineate GGOs of COVID-19 from other lung diseases.

Conclusion

The PointNet++ and the Minkowski tensor based morphological approach together with abnormality analysis will provide radiologists and clinicians with a valuable set of tools when interpreting CT lung scans of COVID-19 patients. Implementation would be particularly useful in countries severely devastated by COVID-19 such as India, where the number of cases has outstripped available resources creating delays or even breakdowns in patient care. This AI-driven approach synthesizes both the unique GGO distribution pattern and severity of the disease to allow for more efficient diagnosis, triaging and conservation of limited resources.

Key Points

Our approach to GGO analysis has four distinguishing features:We combine an unsupervised computer vision approach with convex hull and convex points algorithms to segment and preserve the actual structure of the lung.To the best of our knowledge, we are the first group to use PointNet++ architecture for 3D visualization, segmentation, classification, and pattern analysis of GGOs.We make abnormality predictions using a deep network and Cox proportional hazards model using lung CT images of COVID-19 patients.We quantify the shapes and sizes of GGOs using Minkowski tensors to understand the morphological variations of GGOs within the COVID-19 cohort.

Loss of Smell and Taste in Patients With Suspected COVID-19: Analyses of Patients' Reports on Social Media

BACKGROUND

The year 2020 was the year of the global COVID-19 pandemic. The severity of the situation has become so substantial that many or even most of the patients with mild to moderate symptoms had to self-isolate without specific medical treatments or even without being tested for COVID-19. Many patients joined internet membership groups to exchange information and support each other.

OBJECTIVE

Our goal is to determine the benefits and limits of using social media to understand the symptoms of patients with suspected COVID-19 with mild to moderate symptoms and, in particular, their symptoms of anosmia (loss of the sense of smell) and ageusia (loss of the sense of taste). The voluntary reports on an internet website of a membership group will be the platform of the analyses.

METHODS

Posts and comments of members of an internet group known as COVID-19 Smell and Taste Loss, founded on March 24, 2020, to support patients with suspected COVID-19 were collected and analyzed daily. Demographic data were collected using the software mechanism called Group Insights on the membership group website.

RESULTS

Membership groups on social media have become rare sources of support for patients with suspected COVID-19 with mild to moderate symptoms. These groups provided mental support to their members and became resources for information on COVID-19 tests and medicines or supplements. However, the membership was voluntary, and often the members leave without notification. It is hard to be precise from the free voluntary reports. The number of women in the group (6995/9227, 75.38% as of October 12, 2020) was about three times more than men (2272/9227, 24.62% as of October 12, 2020), and the peak age of members was between 20-40 years in both men and women. Patients who were asymptomatic other than the senses comprised 14.93% (53/355) of the total patients. Recovery of the senses was higher in the patients who were asymptomatic besides having anosmia and ageusia. Most (112/123, 91.06%) patients experienced other symptoms first and then lost their senses, on average, 4.2 days later. Patients without other symptoms tended to recover earlier (P=.02). Patients with anosmia and ageusia occasionally reported distorted smell and taste (parosmia and dysgeusia) as well as experiencing or perceiving the smell and taste without the sources of the smell or taste (phantosmia and phantogeusia).

CONCLUSIONS

Our analysis of the social media database of suspected COVID-19 patients' voices demonstrated that, although accurate diagnosis of patients is not always obtained with social media-based analyses, it may be a useful tool to collect a large amount of data on symptoms and the clinical course of worldwide rapidly growing infectious diseases.

Clinical and Pathophysiologic Spectrum of Neuro-COVID

Though the lungs are predominantly affected in SARS-CoV-2-infected patients, extra-pulmonary manifestations can occur. Extra-pulmonary manifestations of the central and peripheral nervous system need to be recognised as they can strongly determine the outcome. This mini-review summarises and discusses previous and recent findings about neuro-COVID. The spectrum of central nervous system disease in COVID-19 patients is much broader than so far anticipated. Peripheral nerves and the skeletal muscle are less predominantly affected. In the vast majority of the cases, there is no direct attack of the virus towards vulnerable structures, which explains why various manifestations of the nervous system manifest favourably to immune suppression or immune modulation. Overall, the pathophysiology and clinical presentation of CNS/PNS involvement in COVID-19 is wider than believed. All patients with COVID-19 should be investigated by the neurologist for primary or secondary involvement of the CNS/PNS in the infection. neuro-COVID responds favourably to immune suppressants or immune modulation.

Focused Review: Potential Rare and Atypical Symptoms as Indicator for Targeted COVID-19 Screening

The global pandemic of the coronavirus disease 2019 is a known consequence of infection of severe respiratory syndrome coronavirus-2 (SARS-CoV-2). It has affected nations worldwide with soaring number of cases daily. Symptoms such as fever, cough, and shortness of breath, diarrhea, nausea and vomiting are commonly presented in COVID-19 patients. This focused review aims to discuss these uncommon and atypical COVID-19 symptoms that may be presented which might affect neurological, cardiovascular, cutaneous and ocular systems and their possible mode of actions. Nonetheless, there are some cases of reported uncommon or atypical symptoms which may warrant healthcare professionals to be aware of, especially when in contact with patients. The knowledge and information concerning these symptoms might be able to provide additional cues for healthcare professional by subjecting patients to COVID-19 screening. Meanwhile, it might be able to further enhance the alertness and additional precautions being taken by healthcare personnel, which eventually lead to reduced risk of infections.

Radiologic Assessment of the Sinonasal Tract, Nasopharynx and Mastoid Cavity in Patients with SARS-Cov-2 Infection Presenting with Acute Neurological Symptoms

BACKGROUND

Acute neurological sequela in patients with COVID-19 infection include acute thromboembolic infarcts related to cytokine storm and post infectious immune activation resulting in a prothrombotic state. Radiologic imaging studies of the sinonasal tract and mastoid cavity in patients with COVID-19 infection are sparse and limited to case series. In this report, we investigate the radiologic involvement of nasal cavity, nasopharynx, paranasal sinuses, and mastoid cavity in patients with SARS-CoV-2 infection who presented with acute neurological symptoms.

METHODS

Retrospective review of medical records and neuroradiologic imaging in patients diagnosed with acute COVID-19 infection who presented with acute neurological symptoms to assess radiologic prevalence of sinus and mastoid disease and its correlation to upper respiratory tract symptoms.

RESULTS

Of the 55 patients, 23 (42%) had partial sinus opacification, with no evidence for complete sinus opacification. The ethmoid sinus was the most commonly affected (16/55 or 29%). An air fluid level was noted in 6/55 (11%) patients, most commonly in the maxillary sinus. Olfactory recess and mastoid opacification were uncommon. There was no evidence of bony destruction in any of the studies, Cough, nasal congestion, rhinorrhea, and sore throat were not significantly associated with any radiological findings.

CONCLUSION

In patients who present with acute neurological symptoms, COVID-19 infection is characterized by limited and mild mucosal disease within the sinuses, nasopharynx and mastoid cavity.

LEVEL OF EVIDENCE

4.

The incidence of anosmia in patients with laboratory-confirmed COVID 19 infection in India: An observational study

BACKGROUND AND AIMS

Acute loss of smell or anosmia is a common and sometimes the only symptom observed in patients with coronavirus disease-2019 (COVID-19). The objective of the study was to determine the prevalence, time of onset, and duration of anosmia in patients with COVID-19 infection and the association of anosmia with other symptoms and eosinophil count.

MATERIAL AND METHODS

Two hundred patients with laboratory-confirmed COVID-19 infection, who were asymptomatic or mildly symptomatic were assessed for olfaction with a nonirritant odor. The presence of anosmia was recorded, and a questionnaire integrating the anosmia reporting tool was filled. Patients with anosmia/hyposmia were followed telephonically at 7 and 14 days for resolution of anosmia and other symptoms. The presence of anosmia was correlated with eosinophil count.

RESULTS

Of the 200 COVID-19 patients, 87% were symptomatic. More than half of the patients had fever (56%). Anosmia was observed in 30% of the patients and hyposmia in 4% of patients. In 41% of the patients, olfactory loss was reported before diagnosis. The mean duration of anosmia was 7.8 (± 5) days; 97% of patients recovered with a resolution of symptoms within 2 weeks. Ageusia was the most commonly and significantly associated symptom with anosmia (66%, n = 45) followed by sore throat (41%), and rhinorrhea (28%). The symptoms in both the sexes were comparable. Absolute eosinophil count of <40/μL was observed in 59 patients (29.5%) and an absolute eosinophil count of 0 in 17 patients (8.5%). Among the 68 anosmic patients, 36 (47%) patients had eosinopenia, which was statistically significant.

CONCLUSION

Anosmia is an early and sometimes the only symptom in approximately one-third of the patients with COVID-19 infection. Eosinophil count should be checked in anosomic patient with suspicion of COVID-19 infection. Objective tools for olfactory and gustatory assessment should be brought into practice for early and prompt diagnosis to control the spread of the disease.

Neuroradiological Features of Mild and Severe SARS-CoV-2 Infection

RATIONALE AND OBJECTIVES

An increasing number of neurological complications and corresponding radiological findings have been reported in patients with COVID-19 infection. The purpose of this study is to systematically review the current literature on COVID-19-associated neuroradiological findings and examine the prevalence of different findings in patients with both severe and mild COVID-19 infection.

MATERIALS AND METHODS

A comprehensive literature search of the PubMed and Embase databases was performed. Any studies reporting CT or MRI neuroimaging findings in patients with confirmed COVID-19 infection were included. Patient demographics, main radiological findings, neurological symptoms, and severity of COVID-19 infection were tabulated and quantified according to infection severity.

RESULTS

Sixty-one studies published between 2019 and 2020 comprising 711 patients were analyzed according to severity of respiratory symptoms. The main neuroradiological findings for patients with mild classification were cranial nerve abnormalities, ischemic infarction, and white matter abnormalities, while the main findings in patients with severe classification were white matter abnormalities, ischemic infarction, and hemorrhagic events.

CONCLUSION

Neuroradiological manifestations in COVID-19 infection are highly heterogeneous and differ based on the severity of COVID-19 infection. Cranial nerve abnormalities appear exclusive to mild infection, with a high degree of olfactory tract involvement, while hemorrhagic events are more common in severe infection. Notably, ischemic infarction was equally prevalent in both mild and severe COVID-19 infection. Healthcare providers treating COVID-19 patients should be aware of these potential complications and consider neurological assessment and neuroimaging studies when indicated.

SARS-CoV-2 Infectivity and Neurological Targets in the Brain

The gateway for invasion by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into human host cells is via the angiotensin-converting enzyme 2 (ACE2) transmembrane receptor expressed in multiple immune and nonimmune cell types. SARS-CoV-2, that causes coronavirus disease 2019 (COVID-19; CoV-19) has the unusual capacity to attack many different types of human host cells simultaneously via novel clathrin- and caveolae-independent endocytic pathways, becoming injurious to diverse cells, tissues and organ systems and exploiting any immune weakness in the host. The elicitation of this multipronged attack explains in part the severity and extensive variety of signs and symptoms observed in CoV-19 patients. To further our understanding of the mechanism and pathways of SARS-CoV-2 infection and susceptibility of specific cell- and tissue-types and organ systems to SARS-CoV-2 attack in this communication we analyzed ACE2 expression in 85 human tissues including 21 different brain regions, 7 fetal tissues and 8 controls. Besides strong ACE2 expression in respiratory, digestive, renal-excretory and reproductive cells, high ACE2 expression was also found in the amygdala, cerebral cortex and brainstem. The highest ACE2 expression level was found in the pons and medulla oblongata in the human brainstem, containing the medullary respiratory centers of the brain, and may in part explain the susceptibility of many CoV-19 patients to severe respiratory distress.