Factors associated with anosmia recovery rate in COVID-19 patients

Functional magnetic resonance imaging in coronavirus disease 2019 induced olfactory dysfunction

OBJECTIVE

To evaluate the functional magnetic resonance imaging changes in the olfactory structures of coronavirus disease 2019 patients experiencing olfactory dysfunction.

METHODS

This study included patients aged 25-65 years who presented with a sudden loss of smell, confirmed coronavirus disease 2019 infection, and persistent olfactory dysfunction for a minimum of 2 months without any treatment.

RESULTS

Irrespective of the side of brain activation, the analysis of the cumulative maximum diameter of the activation zones revealed significantly lower activation in the upper frontal lobe (p = 0.037) and basal ganglia (p = 0.023) in olfactory dysfunction patients. Irrespective of the side of activation, the analysis of the number of activation points demonstrated significantly lower activation in the upper frontal lobe (p = 0.036) and basal ganglia (p = 0.009) in olfactory dysfunction patients.

CONCLUSION

Patients with coronavirus-triggered olfactory dysfunction exhibited lower activity in their basal ganglia and upper frontal lobe.

Olfactory dysfunction among patients with COVID-19

OBJECTIVES

To assess the frequency of olfactory dysfunction (OD) among individuals afflicted with coronavirus disease of 2019 (COVID-19).

METHODS

A comprehensive literature search was carried out across several bibliographical databases (PubMed, Scopus, Google Scholar, and Web of Science) to extract publications in the English language between January 2020 and December 2021 to report the incidence of OD alone or together with gustatory dysfunction (GD) among COVID-19 patients.

RESULTS

Based on eligibility criteria, 84 articles were included from 27 countries, comprising 36,903 patients, of whom 58.1% were females. The generality rates of olfactory impairment alone was 34.60% and in conjunction with GD was 11.36%. Patients with OD were subclassified into various categories, and the prevalence of anosmia was 20.85%, 5.04% for hyposmia, 8.88% for anosmia or hyposmia, 1.84% for parosmia, 0.78% for phantosmia, and 0.02% for hyperosmia, among COVID-19 patients.

CONCLUSION

Clinical features associated with OD, either isolated or in combination with GD, are common in patients with COVID-19 and consider important signs of COVID-19 that may guide clinicians in the early phase of the disease.PROSPERO Reg. No.: 417296.

The Evolution and Application of Artificial Intelligence in Rhinology: A State of the Art Review

OBJECTIVE

To provide a comprehensive overview on the applications of artificial intelligence (AI) in rhinology, highlight its limitations, and propose strategies for its integration into surgical practice.

DATA SOURCES

Medline, Embase, CENTRAL, Ei Compendex, IEEE, and Web of Science.

REVIEW METHODS

English studies from inception until January 2022 and those focusing on any application of AI in rhinology were included. Study selection was independently performed by 2 authors; discrepancies were resolved by the senior author. Studies were categorized by rhinology theme, and data collection comprised type of AI utilized, sample size, and outcomes, including accuracy and precision among others.

CONCLUSIONS

An overall 5435 articles were identified. Following abstract and title screening, 130 articles underwent full-text review, and 59 articles were selected for analysis. Eleven studies were from the gray literature. Articles were stratified into image processing, segmentation, and diagnostics (n = 27); rhinosinusitis classification (n = 14); treatment and disease outcome prediction (n = 8); optimizing surgical navigation and phase assessment (n = 3); robotic surgery (n = 2); olfactory dysfunction (n = 2); and diagnosis of allergic rhinitis (n = 3). Most AI studies were published from 2016 onward (n = 45).

IMPLICATIONS FOR PRACTICE

This state of the art review aimed to highlight the increasing applications of AI in rhinology. Next steps will entail multidisciplinary collaboration to ensure data integrity, ongoing validation of AI algorithms, and integration into clinical practice. Future research should be tailored at the interplay of AI with robotics and surgical education.

Transient Anosmia and Dysgeusia in COVID-19 Disease: A Cross Sectional Study

Objective

This study aims to explore the prevalence of anosmia and dysgeusia and their impact on COVID-19 patients.

Methods

This is a cross-sectional study. Patients diagnosed with COVID-19 between 1st October 2020 and 30th June 2021 were randomly selected from a national COVID-19 registry. COVID-19 cases were diagnosed using molecular testing method which measured the viral E gene. The Anosmia Reporting Tool, and a brief version of the questionnaire on olfactory disorders were used to measure the outcomes via telephone interviews. Data were analysed using SPSS 27 statistics software.

Results

A total of 405 COVID-19 adults were included in this study, 220 (54.3%) were males and 185 (45.8%) were females. The mean±SD age of participants was 38.2 ± 11.3 years. Alterations in the sense of smell and taste were reported by 206 (50.9%), and 195 (48.1%) of the patients, respectively. Sex and nationality of participants were significantly associated with anosmia and dysgeusia (p < 0.001) and (p-value=0.001) respectively. Among patients who experienced anosmia and dysgeusia, alterations in eating habits (64.2%), impact on mental wellbeing (38.9%), concerns that the alterations were permanent (35.4%), and physical implications and difficulty performing activities of daily living (34%) were reported.

Conclusion

Anosmia and dysgeusia are prevalent symptoms of COVID-19 disease, especially among females. Although transient, anosmia and dysgeusia had considerable impact on patient's life. Neuropsychological implications of COVID-19 in acute infection phase and prognosis of anosmia and dysgeusia in COVID-19 are areas for further exploration.

Corrigendum to "The prevalence and long-term health effects of long Covid among hospitalised and non-hospitalised populations: a systematic review and meta-analysis"

[This corrects the article DOI: 10.1016/j.eclinm.2022.101762.].

Efficacy of pentasodium diethylenetriamine pentaacetate in ameliorating anosmia post COVID-19

BACKGROUND

COVID-19 has been frequently demonstrated to be associated with anosmia. Calcium cations are a mainstay in the transmission of odor. One of their documented effects is feedback inhibition. Thus, it has been advocated that reducing the free intranasal calcium cations using topical chelators such as pentasodium diethylenetriamine pentaacetate (DTPA) could lead to restoration of the olfactory function in patients with post-COVID-19 anosmia.

METHODOLOGY

This is a randomized controlled trial that investigated the effect of DTPA on post-COVID-19 anosmia. A total of 66 adult patients who had confirmed COVID-19 with associated anosmia that continued beyond three months of being negative for SARS-CoV-2 infection. The included patients were randomly allocated to the control group that received 0.9 % sodium chloride-containing nasal spray or the interventional group that received 2 % DTPA-containing nasal spray at a 1:1 ratio. Before treatment and 30 days post-treatment, the patients' olfactory function was evaluated using Sniffin' Sticks, and quantitative estimation of the calcium cations in the nasal mucus was done using a carbon paste ion-selective electrode test.

RESULTS

Patients in the DTPA-treated group significantly improved compared to the control group in recovery from functional anosmia to hyposmia. Additionally, they showed a significant post-treatment reduction in the calcium concentration compared to the control group.

CONCLUSION

This study confirmed the efficacy of DTPA in treating post-COVID-19 anosmia.

Impaired olfaction post-coronavirus disease 2019: a systematic review of smell recovery predictive factors

Background

The devastating coronavirus disease (COVID-19) pandemic seemed not yet to cease. Numerous studies regarding its typical sign and symptoms have been done, presenting one of the most promising predictors of the infection: olfactory dysfunction. Although not life-threatening, the symptom could decrease one’s quality of life, especially if persistent throughout their entire life. Among the countless literature regarding loss of smell, only limited studies denote predictors of smell recovery. This systematic review aimed to bridge the knowledge gap of olfactory impairment prevalence and recovery predictors in people with COVID-19.

Methods

This review was carried out through journal databases, including PubMed, Science Direct, Google Scholar, and medRxiv. Literature published from 2020 to 2022 that complied with the inclusion and exclusion criteria was retrieved, scanned for duplicates with Zotero, and reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols 2020 (PRISMA) guidelines.

Results

Of the 2243 studies, seven were assessed with the Prediction model Risk Of Bias ASsessment Tool (PROBAST) to analyze the risk of bias, which five cohort studies deemed relevant. Olfactory dysfunction, olfactory recovery, and its predictive factors are noted. This review is registered in PROSPERO (Registration Number CRD42022318412).

Conclusions

No clinical markers predicted the recovery of olfactory dysfunction, but patients who are more likely to recover are associated with younger age, female sex, and having COVID-19-related symptoms such as nasal congestion and trigeminal sensation. Modifiable factors are still dubious in predicting the olfaction recovery.

Relation between Vitamin B12 Levels and Smell Affection in COVID-19 Patients

Introduction  Olfactory and gustative alterations are frequent in the initial stages of the COVID-19 infection. Vitamin B12 deficiency has been linked to olfactory dysfunction.

Objective  The present study aimed to assess the relationship between vitamin B12 levels and smell affection in COVID-19 patients.

Methods  The present study included 201 laboratory-confirmed COVID-19 patients. Smell affection was assessed using self-rated olfactory function. Serum vitamin B12 levels were assessed using commercial enzyme-linked immunosorbent assay (ELISA) kits.

Results  According to the smell function assessment, the patients were classified into three categories: normal osmesis ( n  = 77), hyposmia ( n  = 49), and anosmia ( n  = 75) ( Fig. 1 ). Four weeks later, 195 patients (97.0%) had their normal smell function restored. The remainder 6 patients included 4 anosmic and 2 hyposmic patients. Patients with hyposmia or anosmia had significantly lower vitamin B12 levels when compared with patients with normal osmesis (median [IQR]: 363.0 [198.0–539.0] versus 337.0 [175.0–467.0] and 491.0 [364.5–584.5] pg/ml, respectively, p  < 0.001).

Conclusion  Vitamin B12 appears to have some contribution to smell affection in patients with COVID-19 infection.

Impact of COVID-19 versus chronic rhinosinusitis/rhinitis associated olfactory dysfunction on health utility and quality of life

Background

Olfactory dysfunction (OD) is associated with both post-viral and inflammatory etiologies such as COVID-19 and chronic rhinosinusitis/rhinitis (CRS/R) respectively, to result in reduced quality of life (QoL). However, the former typically induces a sudden-onset OD while the latter has a gradual presentation. This study aims to establish and compare health utility values (HUVs) and olfactory-specific QoL measurements between patients with COVID-19 and CRS/R related OD.

Methods

This prospective study surveyed COVID-19 and CRS/R patients with self-reported OD using HUV assessments (EuroQol-visual analog scale [EQ-VAS], EuroQol-5 dimension [EQ-5D], time trade-off [TTO]) and olfactory and sinonasal QoL measures (questionnaire of olfactory disorders -negative and positive statements [QOD-NS + PS] and sino-nasal outcome test [SNOT-22]). A subgroup of subjects completed objective olfactory testing. Intergroup mean scores were compared using Mann-Whitney U tests.

Results

One hundred eleven subjects were enrolled: mean age ± SD (43.0 ± 15.4 years), 55.9% female. CRS/R was associated with lower HUVs as measured by EQ-VAS (CRS/R: 0.67 ± 0.18 vs. COVID-19: 0.74 ± 0.19, p = .03) and worse SNOT-22 scores in both overall (CRS/R: 49.03 ± 21.04 vs. COVID-19: 27.58 ± 18.45, p < .001) and subgroup analysis of objectively confirmed OD subjects (CRS/R: 52.40 ± 22.78 vs. COVID-19: 29.84 ± 21.10, p = .01). On the other hand, COVID-19 has greater burden on olfactory-specific QoL (QOD-NS + PS, COVID-19: 23.19 ± 13.73 vs. CRS/R: 17.25 ± 11.38, p = .04). Both groups demonstrated a similar decrease in health using the EQ-5D assessment.

Conclusion

CRS/R associated OD has a more severe impact on general health and sinonasal specific QoL outcomes, while COVID-19 associated OD has a greater burden on olfactory-specific QoL.

Level of evidence

Level 2c.

Analysis of Prevalence and Predictive Factors of Long-Lasting Olfactory and Gustatory Dysfunction in COVID-19 Patients

Background: Although smell and taste disorders are highly prevalent symptoms of COVID-19 infection, the predictive factors leading to long-lasting chemosensory dysfunction are still poorly understood. Methods: 102 out of 421 (24.2%) mildly symptomatic COVID-19 patients completed a second questionnaire about the evolution of their symptoms one year after the infection using visual analog scales (VAS). A subgroup of 69 patients also underwent psychophysical evaluation of olfactory function through UPSIT. Results: The prevalence of chemosensory dysfunction decreased from 82.4% to 45.1% after 12 months, with 46.1% of patients reporting a complete recovery. Patients older than 40 years (OR = 0.20; 95% CI: [0.07, 0.56]) and with a duration of loss of smell longer than four weeks saw a lower odds ratio for recovery (OR = 0.27; 95% CI: [0.10, 0.76]). In addition, 28 patients (35.9%) reported suffering from parosmia, which was associated with moderate to severe taste dysfunction at the baseline (OR = 7.80; 95% CI: [1.70, 35.8]). Among the 69 subjects who underwent the UPSIT, 57 (82.6%) presented some degree of smell dysfunction, showing a moderate correlation with self-reported VAS (r = −0.36, p = 0.0027). Conclusion: A clinically relevant number of subjects reported persistent chemosensory dysfunction and parosmia one year after COVID-19 infection, with a moderate correlation with psychophysical olfactory tests.