COVID-19 Anosmia: High Prevalence, Plural Neuropathogenic Mechanisms, and Scarce Neurotropism of SARS-CoV-2?

Viruses, Journal Year: 2021, Volume and Issue: 13(11), P. 2225 - 2225

Published: Nov. 4, 2021

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative pathogen of disease 2019 (COVID-19). It known as a virus, but SARS-CoV-2 appears equally, or even more, infectious for olfactory epithelium (OE) than in nasal cavity. In light small area OE relative to epithelium, high prevalence dysfunctions (ODs) COVID-19 has been bewildering and attracted much attention. This review aims first examine cytological molecular biological characteristics OE, especially microvillous apical surfaces sustentacular cells abundant receptor molecules thereof, that may underlie susceptibility this neuroepithelium infection damages. The possibility neurotropism, lack it, then analyzed with regard expression (angiotensin-converting enzyme 2) priming protease (transmembrane serine 2), cellular targets infection. Neuropathology bulb, other related neural structures are also reviewed. Toward end, we present our perspectives regarding possible mechanisms neuropathogenesis ODs, absence substantial viral neurons. Plausible causes persistent ODs some convalescents examined.

Language: Английский

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Prevalence of olfactory dysfunction and quality of life in hospitalised patients 1 year after SARS-CoV-2 infection: a cohort study

BMJ Open, Journal Year: 2022, Volume and Issue: 12(1), P. e054598 - e054598

Published: Jan. 1, 2022

To determine the long-term prevalence of olfactory and/or gustatory dysfunction (OD±GD), associated risk factors and impact on quality life (QoL) in previously hospitalised patients with COVID-19 1 year after infection.A single-centre cohort study.Patients admitted at a large central London hospital infection between 10 February 2020 22 May 2020.150 adult subjects confirmed SARS-CoV-2 were recruited December 29 January 2021. Participants predominantly male (102/150, 68.0%); mean age 58.0±15.9 years 41.2% (56/136) black, Asian minority ethnic backgrounds.EQ-5D-5L values Sino-Nasal Outcome Test-22 (SNOT-22) scores.Long-term OD±GD was 12.8% (19/149) median time 264.5 days following onset. Patients had significantly higher total SNOT-22 score (46.1; Q1-Q3: 23.0-60.0; 95% CI 23.0 to 60.0) compared those without (16.0; 5.0-30.5; 12.0 18.0) (p=0.0002), reflecting poorer QoL, particularly psychological well-being (p=0.0004), which not alleviated (p=0.4977). Median EQ-5D-5L value different (0.70; 0.38-0.83; 0.38 0.83) (0.83; 0.61-0.94; 0.75 0.89) (p=0.0627). Age, sex, ethnicity, smoking status, highest C reactive protein value, intubation ventilation, oxygen supplementation found influence (p>0.05).12.8% still report persistent problems smell or taste up infection, impacting their QoL. Increased holistic support including therapy rehabilitation for affected may help reduce morbidity.

Language: Английский

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Pathogenesis and progression of anosmia and dysgeusia during the COVID-19 pandemic

European Archives of Oto-Rhino-Laryngology, Journal Year: 2022, Volume and Issue: 280(2), P. 505 - 509

Published: Oct. 9, 2022

Language: Английский

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Olfactory Dysfunction in Patients With Coronavirus Disease 2019: A Review

Frontiers in Neurology, Journal Year: 2022, Volume and Issue: 12

Published: Jan. 18, 2022

The coronavirus disease 2019 (COVID-19) pandemic is wreaking havoc on public-health and economic systems worldwide. Among the several neurological symptoms of patients with COVID-19 reported in clinical practice, olfactory dysfunction (OD) most common. OD occurs as earliest or only manifestation some patients. Increasing research attention has focused OD, which listed one main diagnostic severe acute respiratory syndrome-coronavirus-2 infection. Multiple basic-science studies COVID-19-induced are underway to clarify underlying mechanism action. In this review, we summarize characteristics, mechanisms, evaluation methods, prognosis, treatment options OD. way, hope improve understanding aid early identification precise intervention.

Language: Английский

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Effect of Post-COVID-19 on Brain Volume and Glucose Metabolism: Influence of Time Since Infection and Fatigue Status

Brain Sciences, Journal Year: 2023, Volume and Issue: 13(4), P. 675 - 675

Published: April 18, 2023

Post-COVID-19 syndrome (PCS) fatigue is typically most severe <6 months post-infection. Combining magnetic resonance imaging (MRI) and positron emission tomography (PET) with the glucose analog [18F]-Fluorodeoxyglucose (FDG) provides a comprehensive overview of effects PCS on regional brain volumes metabolism, respectively. The primary purpose this exploratory study was to investigate differences in MRI/PET outcomes between people < 6 (N = 18, 11 female) > 15, after COVID-19. secondary assess if any were associated symptoms. Subjects showed smaller putamen, pallidum, thalamus compared subjects months. In months, fatigued had frontal areas non-fatigued subjects. Moreover, worse several results revealed no metabolism However, both groups exhibited hypo- hypermetabolism normative database. These suggest that may alter but not particularly those experiencing

Language: Английский

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The immune mechanism of the nasal epithelium in COVID-19–related olfactory dysfunction

Frontiers in Immunology, Journal Year: 2023, Volume and Issue: 14

Published: July 17, 2023

During the first waves of coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome 2 (SARS-CoV-2) infection, olfactory dysfunction (OD) was reported as a frequent clinical sign. The nasal epithelium is one front-line protections against viral infections, and immune responses mucosa may be associated with OD. Two mechanisms underlying OD occurrence in COVID-19 have been proposed: infection sustentacular cells inflammatory reaction epithelium. former triggers latter likely prolongs These two alternative act parallel; more important for because are to entry point SARS-CoV-2 than neurons susceptible early injury. Furthermore, abundantly express transmembrane protease, serine (TMPRSS2) play major role has revealed crucial roles cells. This review aims elucidate how contribute COVID-19–related Understanding aid development improved medical treatments

Language: Английский

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Recovery rates and long‐term olfactory dysfunction following COVID‐19 infection

World Journal of Otorhinolaryngology - Head and Neck Surgery, Journal Year: 2024, Volume and Issue: 10(2), P. 121 - 128

Published: March 19, 2024

Olfactory dysfunction is one of the most recognized symptoms COVID-19, significantly impacting quality life, particularly in cases where recovery prolonged. This review aims to explore patterns olfactory post-COVID-19 infection, with particular focus on delayed recovery.

Language: Английский

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Mechanistic Understanding of the Olfactory Neuroepithelium Involvement Leading to Short-Term Anosmia in COVID-19 Using the Adverse Outcome Pathway Framework

Cells, Journal Year: 2022, Volume and Issue: 11(19), P. 3027 - 3027

Published: Sept. 27, 2022

Loss of the sense smell (anosmia) has been included as a COVID-19 symptom by World Health Organization. The majority patients recover within few weeks postinfection (short-term anosmia), while others report persistent anosmia. Several studies have investigated mechanisms leading to anosmia in COVID-19; however, evidence is scattered, and remain poorly understood. Based on comprehensive review literature, we aim here evaluate current knowledge uncertainties regarding short-term following SARS-CoV-2 infection. We applied an adverse outcome pathway (AOP) framework, well established toxicology, propose sequence measurable key events (KEs) COVID-19. Those KEs are (1) Spike proteins binding ACE-2 expressed sustentacular (SUS) cells olfactory epithelium (OE); (2) viral entry into SUS cells; (3) replication (4) cell death; (5) damage sensory neurons (OE). This AOP-aligned approach allows for identification gaps where more research should be conducted therapeutic intervention could act. Finally, this AOP gives frame explain several disease features can linked specific factors that lead interindividual differences response

Language: Английский

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The Correlation between the Results of the Sniffin’ Sticks Test, Demographic Data, and Questionnaire of Olfactory Disorders in a Hungarian Population after a SARS-CoV-2 Infection

Journal of Clinical Medicine, Journal Year: 2023, Volume and Issue: 12(3), P. 1041 - 1041

Published: Jan. 29, 2023

After a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, smell disorders frequently occur, significantly affecting patients' quality of life (QoL).110 patients with persistent olfactory disorder after coronavirus infection were enrolled. These underwent chemosensory testing using the Sniffin' Sticks test, and completed Questionnaire Olfactory Disorders (QOD).30% reported anosmia, 70% hyposmia. Upon comparing subjective categories, good category matching was observed in 75.3% (i.e., anosmia based on both methods 10 hyposmia 48 cases). Statistical analysis Chi-square test revealed significant result (p = 0.001 *). Between TDI Threshold, Discrimination, Identification) results three report groups hyposmia, parosmia), no differences observed. When QOD compared, consistent correlations found most outcomes. Scale 2 results, significant, although slight correlation by Spearman's (rho 0.213, p 0.027 *) Pearson's 0.201, 0.037 tests.The nonsignificant between objective suggests that these should be interpreted independently. Moreover, adequate management is essential even mild cases.

Language: Английский

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Long-term self-reported symptoms and psychophysical tests in COVID-19 subjects experiencing persistent olfactory dysfunction: a 4-year follow-up study

Frontiers in Neural Circuits, Journal Year: 2025, Volume and Issue: 19

Published: May 7, 2025

Background Since the onset of COVID-19 pandemic, chemosensory dysfunction (CD), including olfactory and taste quantitative (OD/TD), has emerged as a prevalent early symptom in SARS-CoV-2-infected subjects. This study explores prevalence, duration, recovery trajectory COVID-19-related (C19OD), with specific focus on four-year follow-up. Methods Using combination psychophysical tests (Sniffin’ sticks) patient-reported outcome measures (sVAS tVAS), 83 participants were prospectively evaluated for OD parosmia. Factors influencing long-term analysed. Results Baseline assessments revealed 56.6% patients, progressive improvement observed over 4 years. At follow-up, 92.3% patients recovered their olfaction while remaining still reported hyposmia. Younger age training found to be favourable prognostic factors. Conclusion Our findings show that, despite most individuals C19OD recover within first year, subset them continue experience prolonged CD, demonstrating slow, constant meaningful period highlights complexity SARS-CoV-2’s impact function need further research CD pathophysiology aim improve therapeutic approaches C19OD.

Language: Английский

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