Gray matter and episodic memory associations with olfaction in middle-aged to older adults

BACKGROUND

Age-related declines in olfaction contribute to low quality of life and appear to occur with declines in cognitive function, including diminished episodic memory. We tested the hypothesis that low gray matter volume within cortical regions that support olfaction and episodic memory can explain age-related differences in olfactory and episodic memory functions.

METHODS

T1-weighted images, Sniffin' Sticks olfactory measures, and the NIH Toolbox-Cognition Battery were administered to 131 middle-aged to older adults (50-86 years; 66% female). Correlation was used to examine the associations between these measures. A network-based image processing approach was then used to examine the degree to which spatial patterns of gray matter variance were related to the olfactory and cognitive measures. Structural equation modeling was used to characterize the relative specificity of olfactory, cognitive, gray matter, and aging associations.

RESULTS

Olfactory threshold, discrimination, and identification exhibited small to medium effect size associations with episodic memory performance (rs = 0.27-0.42, ps < 0.002). Gray matter volume within medial temporal and orbitofrontal cortex was also related to olfactory (discrimination and identification) and episodic memory function (rs = 0.21-0.36, ps < 0.019). Age and episodic memory explained the same variance in olfaction that was explained by the medial temporal and orbitofrontal pattern of gray matter volume.

CONCLUSIONS

The results of this cross-sectional study suggest that identifying mechanisms contributing to differences in medial temporal and orbitofrontal cortex will advance our understanding of co-morbid olfactory and cognitive declines.

The relationship between survey-based subjective olfactory awareness and objective olfactory function

KEY POINTS

Correlation between symptom-based surveys and objective olfactory testing is variable. For diagnosis and symptom monitoring, surveys should correlate with objective testing. The Odor Awareness Scale (OAS) and Affective Importance of Odor Scale (AIO) showed significant but moderate positive correlations with University of Pennsylvania Scent Identification Test (UPSIT) score.

Living and Coping with Olfactory and Taste Disorders: A Qualitative Study of People with Long-COVID-19

Taste and smell disorders are common symptoms of SARS-CoV-2 acute infection. In post-COVID-19 condition, symptoms can persist leading to disruption in patients' lives, to changes in their coping skills, and to the need to develop strategies for everyday life. This study aimed to describe the perspective of a group of patients with Long-COVID-19, a condition where loss of taste and/or smell was the most predominant symptom. A qualitative descriptive study was conducted. Participants who had suffered SARS-CoV-2 infection and had Long-COVID-19 loss of taste and/or smell were recruited. Purposive sampling was applied, and participants were recruited until data redundancy was reached. In-depth interviews were used for data collection and thematic analysis was applied. Twelve COVID-19 survivors (75% women) were recruited. The mean age of the participants was 55 years, and the mean duration of post-COVID-19 symptoms was 25 months. Three themes were identified: (a) Living with taste and smell disorders, describing the disorders they experience on a daily basis, how their life has changed and the accompanying emotions, (b) Changes and challenges resulting from the loss of taste and smell, changes in habits, self-care and risk in certain jobs or daily activities, (c) Coping with taste and smell disorders, describing the daily strategies used and the health care received. In conclusion, Long-COVID-19 taste and/or smell disorders limit daily life and involve changes in habits, meal preparation, and the ability to detect potentially dangerous situations.

Olfactory dysfunction and its related molecular mechanisms in Parkinson's disease

Changes in olfactory function are considered to be early biomarkers of Parkinson's disease. Olfactory dysfunction is one of the earliest non-motor features of Parkinson's disease, appearing in about 90% of patients with early-stage Parkinson's disease, and can often predate the diagnosis by years. Therefore, olfactory dysfunction should be considered a reliable marker of the disease. However, the mechanisms responsible for olfactory dysfunction are currently unknown. In this article, we clearly explain the pathology and medical definition of olfactory function as a biomarker for early-stage Parkinson's disease. On the basis of the findings of clinical olfactory function tests and animal model experiments as well as neurotransmitter expression levels, we further characterize the relationship between olfactory dysfunction and neurodegenerative diseases as well as the molecular mechanisms underlying olfactory dysfunction in the pathology of early-stage Parkinson's disease. The findings highlighted in this review suggest that olfactory dysfunction is an important biomarker for preclinical-stage Parkinson's disease. Therefore, therapeutic drugs targeting non-motor symptoms such as olfactory dysfunction in the early stage of Parkinson's disease may prevent or delay dopaminergic neurodegeneration and reduce motor symptoms, highlighting the potential of identifying effective targets for treating Parkinson's disease by inhibiting the deterioration of olfactory dysfunction.

Determining the minimal clinically important difference for the questionnaire of olfactory disorders in people with cystic fibrosis and factors associated with improvement after highly effective modulator therapy

INTRODUCTION

Olfactory dysfunction (OD) is common among people with cystic fibrosis (PwCF). The Questionnaire of Olfactory Disorders (QOD) is a validated instrument that evaluates olfactory-specific quality-of-life. The QOD minimal clinically important difference (MCID) and factors associated with olfactory improvement after elexacaftor/tezacaftor/ivacaftor have not been determined for PwCF.

METHODS

Prospective observational data were pooled from three studies that enrolled adult PwCF with chronic rhinosinusitis (CRS). QOD scores and disease characteristics were assessed. To evaluate internal consistency and calculate the QOD MCID, Cronbach's alpha and four distribution-based methods were employed. For participants who enrolled prior to elexacaftor/tezacaftor/ivacaftor, QOD scores were obtained at baseline and after elexacaftor/tezacaftor/ivacaftor initiation. Multivariable regression was used to identify factors associated with QOD improvement.

RESULTS

Of 129 PwCF included, 65 had QOD scores before and 3-6 months after starting elexacaftor/tezacaftor/ivacaftor. Mean baseline QOD score was 6.5 ± 7.9. Mean Cronbach's alpha was ≥0.85. The MCID estimates were as follows: Cohen's effect size = 1.6, standard error of measurement = 2.5, ½ baseline standard deviation = 4.0, and minimal detectable change = 6.9. Mean MCID was 3.7. Of those with pre/post elexacaftor/tezacaftor/ivacaftor QOD scores, the mean change in QOD was -1.3 ± 5.4. After elexacaftor/tezacaftor/ivacaftor, QOD improvement surpassed the MCID in 22% of participants (14/65). Worse baseline QOD scores and nasal polyps were associated with improved QOD scores after elexacaftor/tezacaftor/ivacaftor (both p < 0.04).

CONCLUSION

The QOD MCID in PwCF was estimated to be 3.7. Elexacaftor/tezacaftor/ivacaftor led to qualitative but not clinically meaningful improvements in QOD score for most PwCF; PwCF with worse baseline QOD scores and nasal polyps improved in a clinically significant manner.

Clinical factors influencing olfactory performance in patients with persistent COVID-19 smell loss longer than 1 year

Objectives

Factors affecting persistence of COVID-19-related olfactory dysfunction (OD) remain partially unknown. We aim to evaluate the clinical factors which could influence olfactory performance in patients with persistent COVID-19-related smell loss.

Methods

A retrospective analysis of 100 patients with persistent COVID-19-related OD was performed between October 2020 and December 2022 at a single-center long-COVID smell clinic. All subjects underwent smell assessment using Sniffin' Sticks (S'S) extended test, nasal endoscopy, nasal airflow evaluation (peak nasal inspiratory flow [PNIF]), allergy test (skin prick test [SPT]) for common aeroallergens, MRI of the head and patient-reported outcome measures (PROMs-VAS, SF-36, Short QOD-NS, SNOT-22). Based on S'S score, subjects were divided into normosmics (TDI ≥ 30.75) and dysosmics (TDI < 30.75).

Results

The median age was 42 years and the median length of patient-reported OD was 1.4 years. 20 patients (20.0%) were normosmic at the time of S'S assessment. Dysosmic patients were found to have significantly lower scores at the SF-36 health domains for energy/fatigue (p = .0004) and emotional wellbeing (p = .04) when compared to normosmics. A moderate correlation (r = .45-.59) between S'S scores and some PROMs was also demonstrated. At the multivariate analysis higher PNIF scores positively influenced odor threshold (p = .001) while positivity to SPT negatively influenced odor identification (p = .04).

Conclusions

Impairment of nasal airflow and sensitivity to aeroallergens can negatively affect olfactory performance in COVID-19-related OD. Long-COVID smell loss deeply affects QoL although recovery of olfaction can bring it back to a normal range.

Level of Evidence

IV.

[Artificial intelligence-assisted prediction of olfactory disorders in patients with chronic rhinosinusitis]

Objective:To analyze the influencing factors and perform the prediction of olfactory disorders in patients with chronic rhinosinusitis（CRS） based on artificial intelligence. Methods:The data of 75 patients with CRS who underwent nasal endoscopic surgery from October 2021 to February 2023 in the Department of Otorhinolaryngology Head and Neck Surgery, the Third Affiliated Hospital of Sun Yat-sen University were analyzed retrospectively. There were 53 males and 22 females enrolled in the study, with a median age of 42.0 years old. The CRS intelligent microscope interpretation system was used to calculate the proportion of area glands and blood vessels occupy in the pathological sections of each patient, and the absolute value and proportion of eosinophils, lymphocytes, plasma cells and neutrophils. The patients were grouped according to the results of the Sniffin' Sticks smell test, and the clinical baseline data, differences in nasal mucosal histopathological characteristics, laboratory test indicators and sinus CT were compared between the groups. Determine the independent influencing factors of olfactory disorders and receiver operating characteristic curves（ROC） were used to evaluate the performance of the prediction model. Statistical analysis was performed using SPSS 25.0 software. Results:Among the 75 CRS patients, 25 cases（33.3%） had normal olfaction and 50 cases（66.7%） had olfactory disorders. Multivariate Logistic regression analysis showed that tissue eosinophils percentage（OR=1.032, 95%CI 1.002-1.064, P=0.036）, Questionnaire of olfactory disorders-Negative statement（QOD-NS）（OR=1.079, 95%CI 1.004-1.160, P=0.040） and Anterior olfactory cleft score（AOCS）（OR=2.672, 95%CI 1.480-4.827, P=0.001） were independent risk factors for olfactory disorders in CRS patients. Further research found that the area under the ROC curve（AUC） of the combined prediction model established by the tissue eosinophil percentage, QOD-NS and AOCS was 0.836（95%CI 0.748-0.924, P<0.001）, which is better than the above single factor prediction model in predicting olfactory disorders in CRS. Conclusion:Based on pathological artificial intelligence, tissue eosinophil percentage, QOD-NS and AOCS are independent risk factors for olfactory disorders in CRS patients, and the combination of the three factors has a good predictive effect on CRS olfactory disorders.

Determining the association of insurance coverage and survival outcomes in patients with olfactory neuroblastoma utilizing machine learning

KEY POINTS

We use machine learning to examine health insurance and mortality in olfactory neuroblastoma. Private insurance significantly improved survival even after adjusting for confounders. The regression model also found no statistical difference between Medicare and no insurance.

Psychophysical assessment of olfactory and gustatory function in post-mild COVID-19 patients: A matched case-control study with 2-year follow-up

BACKGROUND

The aim of this study was to psychophysically evaluate the prevalence of smell and taste dysfunction 2 years after mildly symptomatic severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection compared to that observed at 1-year follow-up and while considering the background of chemosensory dysfunction in the no-coronavirus disease 2019 (COVID-19) population.

METHOD

This is a prospective case-control study on 93 patients with polymerase chain reaction (PCR)-positive SARS-CoV-2 infection and 93 matched controls. Self-reported olfactory and gustatory dysfunction was assessed by 22-item Sino-Nasal-Outcome Test (SNOT-22), item "Sense of smell or taste." Psychophysical orthonasal and retronasal olfactory function and gustatory performance were estimated using the extended Sniffin' Sticks test battery, 20 powdered tasteless aromas, and taste strips test, respectively. Nasal trigeminal sensitivity was assessed by sniffing a 70% solution of acetic acid.

RESULTS

The two psychophysical assessments of chemosensory function took place after a median of 409 days (range, 366-461 days) and 765 days (range, 739-800 days) from the first SARS-CoV-2-positive swab, respectively. At 2-year follow-up, cases exhibited a decrease in the prevalence of olfactory (27.9% vs. 42.0%; absolute difference, -14.0%; 95% confidence interval [CI], -21.8% to -2.6%; p = 0.016) and gustatory dysfunction (14.0% vs. 25.8%; absolute difference, -11.8%; 95% CI, -24.2% to 0.6%; p = 0.098). Subjects with prior COVID-19 were more likely than controls to have an olfactory dysfunction (27.9% vs. 10.8 %; absolute difference, 17.2%; 95% CI, 5.2% to 28.8%) but not gustatory dysfunction (14.0% vs. 9.7%; absolute difference, 4.3%; 95% CI, -5.8% to 14.4% p = 0.496) still 2 years after the infection. Overall, 3.2% of cases were still anosmic 2 years after the infection.

CONCLUSIONS

Although a proportion of subjects recovered from long-lasting smell/taste dysfunction more than 1 year after COVID-19, cases still exhibited a significant excess of olfactory dysfunction 2 years after SARS-CoV-2 infection when compared to matched controls.

Bacterial communities in the nasal passage of postviral olfactory dysfunction patients

KEY POINTS

Bacterial composition is uniform in the sinuses of postviral olfactory dysfunction patients. Significant reduction of genus Corynebacterium in PVOD patients compared to controls.

Patient Insights into the Diagnosis of Smell and Taste Disorders in the United States

OBJECTIVES

Diagnosis of smell/taste dysfunction is necessary for appropriate medical care. This study examines factors affecting testing and diagnosis of smell/taste disorders .

METHODS

The online USA Smell and Taste Patient Survey was made available to US patients with smell/taste disorders between April 6-20, 2022. 4,728 respondents were included.

RESULTS

1,791 (38%) patients reported a documented diagnosis. Patients most often saw family practitioners (34%), otolaryngologists (20%), and Taste/Smell clinics (6%) for smell/taste dysfunction. 64% of patients who went to Taste/Smell clinics received smell testing, followed by 39% of patients who saw otolaryngologists, and 31% of patients who saw family practitioners. Factors associated with increased odds of diagnosis included age (25-39 years (OR 2.97, 95% CI [2.25, 3.95]), 40-60 (OR 3.3, 95% CI [2.56, 4.52]), and >60 (OR 4.25, 95% CI [3.21, 5.67]) vs. 18-24 years), male gender (OR 1.26, 95% CI [1.07, 1.48]), insurance status (private (OR 1.61, 95% CI [1.15, 2.30]) or public (OR 2.03, 95% CI [1.42, 2.95]) vs. uninsured), perception of their family practitioner to be knowledgeable (OR 2.12, 95% CI [1.16, 3.90]), otolaryngologic evaluation (OR 6.17, 95% CI [5.16, 7.38]), and psychophysical smell testing (OR 1.77, 95% CI [1.42, 2.22]).

CONCLUSION

Psychophysical testing, otolaryngologic evaluation, patient assessment of family practitioner knowledge level, insurance, age, and gender are significant factors in obtaining smell/taste dysfunction diagnosis. This study identifies barriers to diagnosis including lack of insurance or access to specialist evaluation and highlights the importance of educating family practitioners in diagnosis and management of patients with smell/taste disorders.

Assessment of COVID-19-related olfactory dysfunction and its association with psychological, neuropsychiatric, and cognitive symptoms

Purpose of review

To provide a detailed overview of the assessment of COVID-19-related olfactory dysfunction and its association with psychological, neuropsychiatric, and cognitive symptoms.

Recent findings

COVID-19-related olfactory dysfunction can have a detrimental impact to the quality of life of patients. Prior to the COVID-19 pandemic, olfactory and taste disorders were a common but under-rated, under-researched and under-treated sensory loss. The pandemic has exacerbated the current unmet need for accessing good healthcare for patients living with olfactory disorders and other symptoms secondary to COVID-19. This review thus explores the associations that COVID-19 has with psychological, neuropsychiatric, and cognitive symptoms, and provide a framework and rationale for the assessment of patients presenting with COVID-19 olfactory dysfunction.

Summary

Acute COVID-19 infection and long COVID is not solely a disease of the respiratory and vascular systems. These two conditions have strong associations with psychological, neuropsychiatric, and cognitive symptoms. A systematic approach with history taking and examination particularly with nasal endoscopy can determine the impact that this has on the patient. Specific olfactory disorder questionnaires can demonstrate the impact on quality of life, while psychophysical testing can objectively assess and monitor olfaction over time. The role of cross-sectional imaging is not yet described for COVID-19-related olfactory dysfunction. Management options are limited to conservative adjunctive measures, with some medical therapies described.

Otolaryngology-related symptoms of COVID-19 in children in the post-epidemic era: a cross-sectional web-based survey study

Purpose

China adjusted and optimized its prevention and control strategies in December 2022, and it entered a new era of the coronavirus epidemic. Here, we describe the general and otolaryngology-related symptoms of coronavirus disease 2019 (COVID-19) in children during the first pandemic in the post-epidemic era, focusing on the frequency and severity of smell and taste loss, as well as the recovery process and its influencing factors.

Patients and methods

From 2 January to 7 January 2023, we conducted a cross-sectional online questionnaire survey through Questionnaire Stars in order to collect relevant information about COVID-19 in children in Shenzhen.

Results

A total of 1,247 valid questionnaires were received, with an effective response rate of 78.72%. All of the diagnoses were confirmed by nucleic acid or antigen test for COVID-19. Among the subjects, the sex ratio of male to female was more inclined to male (1.35:1), and the age was 3-16 years, with an average of 10.13 ± 2.82 years old. The most common symptoms were cough (58.24%), stuffy nose (56.18%), headache (42.09%), fatigue (40.44%), and sore throat (31.63%). Approximately 6.43% of the children reported dysosmia, the mean time of the duration of dysosmia was 5.38 ± 2.92 days, and the mean score of the severity of the dysosmia as assessed by visual analogue scale (VAS) was 4.63 ± 2.29. Approximately 13.34% reported dysgeusia, the mean time of the duration of dysgeusia was 4.77 ± 3.98 days, and the mean score of the severity of the dysgeusia as assessed by VAS was 5.12 ± 2.29. Univariate and multivariate logistic regression analysis showed that the prevalence of taste and olfactory disorders increased with age, mainly in children with severe symptoms and older children.

Conclusion

In the post-epidemic era, due to weakening of the pathogenicity of the subvariant of Omicron, overall condition of children with COVID-19 was mild, incidence of olfactory and taste disorders was low, recovery was faster, and prognosis was better. In our study, cough, runny nose, and sore throat were the most common symptoms, and the prevalence of taste and olfactory disorders increased with age, mainly in older children with severe symptoms.

Alzheimer's early detection in post-acute COVID-19 syndrome: a systematic review and expert consensus on preclinical assessments

Introduction

The risk of developing Alzheimer's disease (AD) in older adults increasingly is being discussed in the literature on Post-Acute COVID-19 Syndrome (PACS). Remote digital Assessments for Preclinical AD (RAPAs) are becoming more important in screening for early AD, and should always be available for PACS patients, especially for patients at risk of AD. This systematic review examines the potential for using RAPA to identify impairments in PACS patients, scrutinizes the supporting evidence, and describes the recommendations of experts regarding their use.

Methods

We conducted a thorough search using the PubMed and Embase databases. Systematic reviews (with or without meta-analysis), narrative reviews, and observational studies that assessed patients with PACS on specific RAPAs were included. The RAPAs that were identified looked for impairments in olfactory, eye-tracking, graphical, speech and language, central auditory, or spatial navigation abilities. The recommendations' final grades were determined by evaluating the strength of the evidence and by having a consensus discussion about the results of the Delphi rounds among an international Delphi consensus panel called IMPACT, sponsored by the French National Research Agency. The consensus panel included 11 international experts from France, Switzerland, and Canada.

Results

Based on the available evidence, olfaction is the most long-lasting impairment found in PACS patients. However, while olfaction is the most prevalent impairment, expert consensus statements recommend that AD olfactory screening should not be used on patients with a history of PACS at this point in time. Experts recommend that olfactory screenings can only be recommended once those under study have reported full recovery. This is particularly important for the deployment of the olfactory identification subdimension. The expert assessment that more long-term studies are needed after a period of full recovery, suggests that this consensus statement requires an update in a few years.

Conclusion

Based on available evidence, olfaction could be long-lasting in PACS patients. However, according to expert consensus statements, AD olfactory screening is not recommended for patients with a history of PACS until complete recovery has been confirmed in the literature, particularly for the identification sub-dimension. This consensus statement may require an update in a few years.

Analysis of risk factors affecting olfactory dysfunction in patients with chronic rhinosinusitis: Highlighting the role of metabolic syndrome

Objective

This study aims to evaluate the relationship between chronic sinusitis (CRS) and metabolic syndrome (MS) in a Chinese population and to explore the risk factors for olfactory dysfunction in patients with CRS.

Methods

A total of 387 CRS patients were enrolled. Olfactory function was assessed by the Sniffin' Sticks 12-item test and MS was diagnosed according to the guidelines. Logistic regression analysis was performed on CRS patients to screen independent risk factors of olfactory dysfunction, adjusted for confounding factors.

Results

Among 387 patients, average age of visit and duration of onset were 48.7 years and 1.8 years, respectively. The prevalence of MS was 15.0%. CRS patients with MS were more likely to be older (51.2 vs. 46.8, p = .004), predominantly male (p < .001) and have a higher proportion of olfactory dysfunction (62.1% vs. 44.1%, p = .018) than those without MS. In multivariate logistic regression analysis, MS was associated with olfactory dysfunction in CRS patients (OR: 2.06, 95% CI: 1.14-3.72, p = .016). This association remained significant after controlling for confounding factors. In addition, nasal polyps (OR: 13.41, 95% CI: 8.11-22.17, p < .001) and allergic rhinitis (OR: 3.16, 95% CI: 1.67-5.99, p < .001) were also risk factors for olfactory dysfunction after adjusting for confounding factors.

Conclusions

MS is associated with olfactory dysfunction in patients with CRS. MS, nasal polyps, and allergic rhinitis are risk factors for olfactory dysfunction in CRS patients.

Level of evidence

IV.

Food-related experiences and behavioral responses among people affected by chemosensory dysfunctions following COVID-19: A scoping review

A category of symptoms that became characteristic early in the first wave of the coronavirus disease 2019 (COVID-19) pandemic was chemosensory dysfunctions (alterations of smell and taste). Such symptoms substantially affect food and eating-cornerstones for both nutrition-related health outcomes and for quality of life. Based on this, this scoping review aimed to map out existing scientific literature on food-related experiences and related behavioral responses among people affected by chemosensory dysfunctions following COVID-19. A librarian-supported search of PsycInfo, PubMed, and Scopus for publications written in English (2020 to April 26, 2022) was conducted. Two authors searched for and screened publications and three others extracted and collated data. These are reported following the Preferred Reporting Items of Systematic reviews and Meta-Analyses extension for Scoping Reviews. Of 1169 hits, 9 publications were included in the review. The results are thematized as "Psychological and social aspects" and "Nutritional aspects," each with the subsections "Experiences" and "Behavioral responses." A great variety of food-related problems, nutritional and mental health effects, and implications for social life are identified. People affected by chemosensory dysfunctions following COVID-19 suffer, as evident both in stories from qualitative studies and in measurements of quality of life. The results impact all professions who are and may come to be involved in treating these patients, such as nurses, physicians, dietitians, and psychologists. With more knowledge about the dysfunctions' manifestation, duration, and impact on everyday life, multiprofessional teams need to collaborate in supporting patients medically, psychosocially, and nutritionally.

Olfactory Disorders Questionnaire: Scaling severity of quality-of-life impact

BACKGROUND

The Olfactory Disorders Questionnaire (ODQ) is widely used for patients suffering from olfactory disorders to depict the impact on quality of life. The aim of this study was to scale and produce reference values for patients ODQ score according to Becks Depression Inventory (BDI) severity.

METHODS

In this prospective study, a cross-sectional anonymous survey was created, which combined EQ-5D-5L, BDI and ODQ. Correlation was calculated between the three questionnaires. Receiver operator characteristic curves were created to produce cut-off values for ODQ scores based on three BDI categories (mild, borderline clinical and moderate-to-severe depression).

RESULTS

Of the 578 who responded to the survey, 445 completed all sections and were included in the study. Majority were female (n = 327,73.5%), median age group 55-70 years (n = 193,43.4%). There was a strong correlation between BDI score and total ODQ score. There was a clear gradient in total ODQ score for each BDI classification; those with mild depression had the lowest mean ODQ score (101.8, range 39-168), those with moderate-to-severe depression had the highest (138.24, range 74-177). Due to overlapping of confidence intervals we were unable to grade the ODQ score.

CONCLUSION

The study was unable to generate reference values for the ODQ due to lower numbers of patients with borderline clinical to extreme depression. However, we were able to appreciate the general trend, that the higher the ODQ score, the higher the risk of depression. These findings should guide clinical practice to ensure appropriate care and support is provided for those with olfactory dysfunction.

[Interpretation of the 2021 American Academy of Allergy, Asthma and Immunology expert consensus on the treatment of postinfectious olfactory dysfunction]

Respiratory tract viruses are the second leading cause of olfactory dysfunction. Between 2019 to 2022, the world has been plagued by the problem of olfaction caused by the COVID-19. As we learn more about the impact of severe acute respiratory syndrome coronavirus 2（SARS-CoV-2）, with the recognition that olfactory dysfunction is a key symptom of this disease process, there is a greater need than ever for evidence-based management of postinfectious olfactory dysfunction（PIOD）. The Clinical Olfactory Working Group has proposed theconsensus on the roles of PIOD. This paper is the detailed interpretation of the consensus.

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

BACKGROUND

After a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, smell disorders frequently occur, significantly affecting patients' quality of life (QoL).

METHODS

110 patients with persistent olfactory disorder after coronavirus infection were enrolled. These patients underwent chemosensory testing using the Sniffin' Sticks test, and completed the Questionnaire of Olfactory Disorders (QOD).

RESULTS

30% of the patients reported anosmia, and 70% reported hyposmia. Upon comparing subjective and chemosensory testing categories, good category matching was observed in 75.3% (i.e., anosmia based on both methods in 10 and hyposmia in 48 cases). Statistical analysis using the Chi-square test revealed a significant result (p = 0.001 *). Between the TDI (i.e., Threshold, Discrimination, Identification) results of the three subjective report groups (i.e., hyposmia, anosmia, and parosmia), no significant differences were observed. When the TDI and QOD results were compared, no consistent significant correlations were found in most TDI and QOD outcomes. Between the TDI and Scale 2 results, a significant, although slight correlation was observed by the Spearman's (rho = 0.213, p = 0.027 *) and Pearson's (rho = 0.201, p = 0.037 *) tests.

CONCLUSIONS

The nonsignificant correlation between objective and subjective methods suggests that these results should be interpreted independently. Moreover, adequate management is essential even in mild cases.

Establishing UK research priorities in smell and taste disorders: A James Lind alliance priority setting partnership

OBJECTIVES

To determine the top 10 research priorities in Smell and Taste Disorders (SATD).

DESIGN

After steering group was established, an electronic survey was disseminated to determine the list of questions. After removing out-of-scope responses, the remainder were consolidated to create summary questions. A literature search was conducted to remove already answered questions. A second survey was used to determine the top questions that formed the subject of final debate at a workshop attended by clinicians and patients to determine the top 10 priorities.

SETTING

A James Lind Alliance Priority Setting Partnership (JLAPSP) was established by FifthSense to identify the top 10 research questions in SATDs in the United Kingdom.

PARTICIPANT

All stakeholders in SATDs (patients, healthcare professionals, family, carers, researchers).

MAIN OUTCOME MEASURES

Final 10 research priorities.

RESULTS

The 665 respondents to the initial survey provided 1698 research questions. Thirteen were out-of-scope and removed; remaining 1685 were then consolidated to form 147 summary questions. Following literature search and discussion with the steering group, 37 questions remained for the second survey, which 235 people responded. The top ten priorities agreed upon in the workshop covered themes of improved understanding of pathophysiologlogy, improving health services, and managing long-term effects of smell/taste disorders. The most important research question agreed was "How can we further our understanding of the mechanism of disease in the nerve pathways that affect smell and taste disorders, including where parosmia and phantosmia exist."

CONCLUSION

We report the top 10 research priorities in smell and taste disorders. These priorities will now empower researchers to secure research funding and provide the basis of the FifthSense research hub.

Impairment of quality of life due to COVID-19-induced long-term olfactory dysfunction

Introduction

Olfactory dysfunction is one of many long-lasting symptoms associated with COVID-19, estimated to affect approximately 60% of individuals and often lasting several months after infection. The associated daily life problems can cause a decreased quality of life.

Methods

Here, we assessed the association between perceived quality of life and both qualitative and quantitative olfactory function (distorted and weakened sense of smell, respectively) in 58 individuals who had undergone confirmed SARS-CoV-2 infection and who complained about olfactory dysfunction.

Results

Participants with large quantitative olfactory dysfunction experienced a greater reduction in their quality of life. Moreover, our participants had a high prevalence of qualitative olfactory dysfunction (81%) with a significant correlation between qualitative olfactory dysfunction and daily life impairment. Strong drivers of low quality of life assessments were lack of enjoyment of food as well as worries related to coping with long-term dysfunctions.

Discussion

These results stress the clinical importance of assessing qualitative olfactory dysfunction and the need to develop relevant interventions. Given the poor self-rated quality of life observed, healthcare systems should consider developing support structures, dietary advice, and guidelines adapted to individuals experiencing qualitative olfactory dysfunction.

Association Between Olfactory Test Data with Multiple Levels of Odor Intensity and Suspected Cognitive Impairment: A Cross-Sectional Study

BACKGROUND

Olfactory function decline has recently been reported to be associated with a risk of cognitive impairment. Few population-based studies have included younger adults when examining the association between olfactory test data with multiple odor intensities and suspected cognitive impairment.

OBJECTIVE

We investigated the association between high-resolution olfactory test data with fewer odors and suspected cognitive impairments. We also examined the differences between older and younger adults in this association.

METHODS

The Japanese version of the Montreal Cognitive Assessment (MoCA-J) was administered to 1,450 participants, with three odor-intensity-level olfactometry using six different odors. Logistic regressions to discriminate suspected cognitive impairment were conducted to examine the association, adjusted for age, sex, education duration, and smoking history. Data were collected from the Program by Tohoku University Tohoku Medical Megabank Organization, with an additional olfactory test conducted between 2019 and 2021.

RESULTS

We generally observed that the lower the limit of distinguishable odor intensity was, the higher the MoCA-J score was. The combination of spearmint and stuffy socks contributed most to the distinction between suspected and unsuspected cognitive impairment. Furthermore, the association was significant in women aged 60-74 years (adjusted odds ratio 0.881, 95% confidence interval [0.790, 0.983], p = 0.024).

CONCLUSIONS

The results indicate an association between the limit of distinguishable odor intensity and cognitive function. The olfactory test with multiple odor intensity levels using fewer odors may be applicable for the early detection of mild cognitive impairment, especially in older women aged 60-74 years.

Safety and efficacy of Chinese herbal tonics for the treatment of olfactory disorders caused by the Delta strain in COVID-19: A protocol for systematic review and meta-analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19) is an acute respiratory infectious disease that makes breathing difficult and is often accompanied by olfactory disorders and distension. Chinese herbal tonics, a special external treatment of traditional Chinese medicine, has shown beneficial effects in the treatment of olfactory disorders. Currently, there is a lack of systematic reviews on Chinese herbal tonics for the treatment of olfactory disorders. We conduct this study to evaluate the efficacy and safety of Chinese herbal tonics in the treatment of olfactory disorders. This study is designed to evaluate the effectiveness and safety of Chinese herbal tonics for olfactory disorders in COVID-19.

METHODS

Randomized controlled trials from December 2019 to September 2022. will be included, without restrictions on language or publication date. PubMed, EMBASE, Cochrane Library, Web of Science, Chinese Biomedical Databases, China National Knowledge Infrastructure, Wanfang Database, and VIP Database were searched. Two researchers will independently select studies, extract data, and evaluate study quality. The Cochrane risk of bias tool for randomized trials will be used to assess the risk of bias in the included studies. Statistical analyses will be conducted using the Review Manager (RevMan 5.3, Cochrane Collaboration, Nordic Cochrane Center, Copenhagen, Denmark).

RESULTS

This study aimed to prove the efficacy and safety of Chinese herbal tonics for olfactory disorders in patients with COVID-19. Our study provides a more accurate treatment method for olfactory disorders during COVID-19.We will publish our results in a peer-reviewed journal.

Investigations and Outcomes for Olfactory Disorders

Purpose of Review

To provide a detailed overview of the investigations and core outcome measures for olfactory disorders.

Recent Findings

Olfactory disorders can have a detrimental impact to the quality of life of patients. There are a wide range of causes of olfactory loss including sinonasal conditions, idiopathic, post-head trauma or infection. This review highlights the key investigations and reasoning for their use to clinically assess and research patients with olfactory disorders. In addition, this review outlines the core outcome measures for olfaction that will help inform future research in olfactory disorders.

Summary

A systematic approach with history taking and examination particularly with nasal endoscopy can determine the cause of the olfactory disorder in most cases. Specific olfactory disorder questionnaires can demonstrate the impact on quality of life, while psychophysical testing can objectively assess and monitor olfaction over time. Olfactory-evoked potentials and functional MRI are reserved for research, whereas CT and MRI imaging are used depending on history and examination. A core outcome set for olfaction has been developed that will help standardise the outcome measures used in olfaction and olfactory disorders research.

Efficacy and safety of acupuncture in the treatment of the sequela of olfactory disorders after infection with COVID-19: A protocol for systematic review and meta analysis

BACKGROUND

From the end of 2019 to now, coronavirus disease 2019 (COVID-19) has put enormous strain on the world's health systems. As a characteristic sign of COVID-19 patient, olfactory dysfunction (OD) poses considerable problems for patients. In China, acupuncture has been widely used to treat OD caused by COVID-19, but there is still a lack of evidence-based medical evaluation. This study was designed to evaluate the effectiveness and safety of acupuncture for the treatment of COVID-19 OD.

METHODS

According to the retrieval strategies, randomized controlled trials on the acupuncture for COVID-19 OD were obtained from Cochrane Central Register of Controlled Trials, Embase, PubMed, Web of Science, the Chinese National Knowledge Infrastructure, the Chinese Biomedical Literature Database, the Chinese Scientific Journal Database and the Wanfang Database, regardless of publication date, or language. Studies were screened based on inclusion and exclusion criteria, and the Cochrane risk bias assessment tool was used to evaluate the quality of the studies. The meta-analysis was performed using Review Manager (RevMan 5.3) and STATA 14.2 software. Ultimately, the evidentiary grade for the results will be evaluated.

RESULTS

The results of this meta-analysis will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This study will provide up-to-date summary proof for evaluating the effectiveness and safety of acupuncture for COVID-19 OD.

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.

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.

Patterns of self-reported recovery from chemosensory dysfunction following SARS-CoV-2 infection: insights after 1 year of the pandemic

BACKGROUND

The coronavirus disease (COVID-19), due to the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), causes chemosensory dysfunction.

AIMS/OBJECTIVES

To determine the characteristics of chemosensory dysfunction and to identify factors associated with chemosensory complete recovery and time to recovery.

MATERIALS AND METHODS

This cross-sectional study included all patients presenting with chemosensory dysfunction and confirmed SARS-CoV-2 infection from May to August 2020 who underwent telemedicine follow-up after 1 year to assess their chemosensory recovery.

RESULTS

A total of 372 patients were included, of which 53.8% were male. The mean age ± SD was 37.45 ± 13.44. The majority experienced combined (olfactory and gustatory) dysfunction (85.7%), and 315 patients (84.7%) had complete loss of chemosensory function. The independent predictors associated with a low likelihood of complete recovery were parosmia (aOR 0.16, p < .001), upper respiratory tract symptoms (aOR 0.28, p = .001), and dyspnoea (aOR 0.21, p < .001), whereas the factors associated with a long recovery period were parosmia (aOR 12.04, p = .002), headache (aOR 7.19, p = .007), and hypertension (aOR 7.76, p = .039).

CONCLUSIONS

A full recovery outcome was predominant. The presence of parosmia was linked to both an incomplete recovery and a long time to recovery.

SIGNIFICANCE

Parosmia and respiratory symptoms are implicated in the incomplete recuperation of chemosensory function.

Development of a questionnaire to investigate socio-cultural differences in the perception of smell, taste and flavour

Objectives

Clinical experience and daily life indicate that the importance of smell, taste and flavour is variable among individuals. Therefore, the aim of this research was to develop a questionnaire to investigate the importance attributed to smell, taste and flavour and socio-cultural differences among individuals.

Methods

Cross-cultural adaptation of the questionnaire was executed by two professional translators and one bilingual investigator and pre-tested on a pilot group of 25 subjects with normal smell and taste abilities. The final version of the questionnaire was sent by e-mail to 850 healthy subjects. The Google form consisted of three parts: "The importance of olfaction" developed by Croy et al. in 2010, "The importance of taste and flavour" developed by our team and a section to collect demographic data. The questions were classified into "association", "application", "consequence" and "aggravation". Statistical differences were assessed using t-test with p ≤ 0.05. Correlations were calculated using Spearman's test. Internal consistency was assessed using the Cronbach's Alpha, while test-retest reliability was analysed by calculating the Intraclass Correlation Coefficients (ICC2k).

Results

The questionnaire received a non-response rate of 10.7%. Calculation of Cronbach's alpha showed good internal reliability (a = 0.87). Test-retest evaluation was satisfactory for all subscales, with an overall ICC2k = 0.84 (CI 0.79-0.89). Statistical analysis showed that smell, taste and flavour appeared to be more important for women when compared to men (p < 0.001). No statistical differences were seen between individuals with various educational background (p > 0.05), and the importance of smell (r = 0.16; p < 0.01), taste and flavour (r = 0.08; p < 0.05) did not decline with age.

Conclusions

The development of this original test provides an overview into the importance of smell, taste and flavour among individuals. Although further research is needed, it can help in the evaluation and investigation of aspects that influence people to seek medical attention in the presence of sensory alterations.

Smell-Based Memory Training: Evidence of Olfactory Learning and Transfer to the Visual Domain

Human and non-human animal research converge to suggest that the sense of smell, olfaction, has a high level of plasticity and is intimately associated with visual-spatial orientation and memory encoding networks. We investigated whether olfactory memory (OM) training would lead to transfer to an untrained visual memory (VM) task, as well as untrained olfactory tasks. We devised a memory intervention to compare transfer effects generated by olfactory and non-olfactory (visual) memory training. Adult participants were randomly assigned to daily memory training for about 40 days with either olfactory or visual tasks that had a similar difficulty level. Results showed that while visual training did not produce transfer to the OM task, olfactory training produced transfer to the untrained VM task. Olfactory training also improved participants' performance on odor discrimination and naming tasks, such that they reached the same performance level as a high-performing group of wine professionals. Our results indicate that the olfactory system is highly responsive to training, and we speculate that the sense of smell may facilitate transfer of learning to other sensory domains. Further research is however needed in order to replicate and extend our findings.

Loss of Taste and Smell as Distinguishing Symptoms of Coronavirus Disease 2019

In a household study, loss of taste and/or smell was the fourth most reported symptom (26/42 [62%]) among coronavirus disease 2019 (COVID-19) case patients and had the highest positive predictive value (83% [95% confidence interval [CI], 55%-95%) among household contacts. Olfactory and taste dysfunctions should be considered for COVID-19 case identification and testing prioritization.

Clinical Olfactory Working Group consensus statement on the treatment of postinfectious olfactory dysfunction

BACKGROUND

Respiratory tract viruses are the second most common cause of olfactory dysfunction. As we learn more about the effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with the recognition that olfactory dysfunction is a key symptom of this disease process, there is a greater need than ever for evidence-based management of postinfectious olfactory dysfunction (PIOD).

OBJECTIVE

Our aim was to provide an evidence-based practical guide to the management of PIOD (including post-coronavirus 2019 cases) for both primary care practitioners and hospital specialists.

METHODS

A systematic review of the treatment options available for the management of PIOD was performed. The written systematic review was then circulated among the members of the Clinical Olfactory Working Group for their perusal before roundtable expert discussion of the treatment options. The group also undertook a survey to determine their current clinical practice with regard to treatment of PIOD.

RESULTS

The search resulted in 467 citations, of which 107 articles were fully reviewed and analyzed for eligibility; 40 citations fulfilled the inclusion criteria, 11 of which were randomized controlled trials. In total, 15 of the articles specifically looked at PIOD whereas the other 25 included other etiologies for olfactory dysfunction.

CONCLUSIONS

The Clinical Olfactory Working Group members made an overwhelming recommendation for olfactory training; none recommended monocycline antibiotics. The diagnostic role of oral steroids was discussed; some group members were in favor of vitamin A drops. Further research is needed to confirm the place of other therapeutic options.

Alteration of Smell and Taste in Asymptomatic and Symptomatic COVID-19 Patients in Sicily, Italy

OBJECTIVES

Alteration of smell and taste has been reported in patients with coronavirus disease 2019 (COVID-19). The incidence and clinical-symptomatic manifestation of COVID-19 is different between northern and southern Italy. This study aims to evaluate the onset of alteration of smell and taste in asymptomatic and symptomatic patients in Sicily (extreme south of Italy).

METHODS

This prospective cross-sectional study was performed on asymptomatic and symptomatic COVID-19 patients tested for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) from May 1 to May 15, 2020. A questionnaire was used for evaluating the prevalence of smell and taste disorders in COVID-19 patients before performing nasopharyngeal swab.

RESULTS

Of the total 292 patients, 242 (83.2%) were negative for SARS-CoV-2 and 50 were positive (16.8%). Twenty-six of the 50 (52%) SARS-CoV-2 positive patients reported smell/taste disorders. Twenty-eight of the 50 (57.1%) SARS-CoV-2 positive patients were hospitalized (group A), and 22 (42.9%) were nonhospitalized (group B). The mean age in group A and group B was 45.4 ± 13.7 years and 57.0 ± 15.0, respectively (P = .007). The symptoms reported by hospitalized patients were fever (71.4%), cough (64.2%), fatigue (82.1%), and dyspnea (100%), while in nonhospitalized patients, the most reported symptoms were sore throat (72.7%), rhinorrhea (77.2%), and altered smell (81.8%). Anosmia/hyposmia reported in group A and group B was 28.5% and 81.8%, respectively (P = .001).

CONCLUSION

These preliminary results indicate that the majority of SARS-Cov-2 positive patients in southern Italy did not require hospitalization and presented with milder symptoms or no symptoms and the alterations in smell and taste occurred.

Evaluation of predictive value of olfactory dysfunction, as a screening tool for COVID-19

OBJECTIVES

At the end of 2019, SARS-CoV-2 was identified, the one responsible for the COVID-19 disease. Between a 5.1% and a 98% of COVID-19 patients present some form of alteration in their sense of smell. The objective of this study is to determine the diagnostic yield of the smell dysfunction as screening tool for COVID-19.

METHODS

Cross-sectional, observational, and pro-elective study was performed in a tertiary care hospital from May 25th to June 30th, 2020. One hundred and thirty-nine patients were included in the study. Demographic characteristics were collected from anamnesis. A Self-Perception Questionnaire and psychophysical olfactory test (POT) were applied to all participants. The presence of SARS-CoV2, was detected by RT-PCR methods.

RESULTS

51.7% of patients were SARS-CoV-2 positive. A sensitivity of 50% was obtained for the self-perception questionnaire as a screening tool for SARS-CoV2, with a specificity of 80.59%. The positive predictive value (PPV) was of 73.46%, the negative predictive value (NPV) was of 60%. The POT as a screening tool had a PPV of 82.35%, a NPV of 52.45%, a LR+ of 4.34, a LR- 0.84. The combination of anosmia (according to the POT) plus cough and asthenia got an OR of 8.25 for the SARS CoV-2 infection.

CONCLUSION

There is a strong association between olfactory dysfunction and COVID-19. However, it is not really efficient in the screening of SARS-CoV-2 infection and thus, they should not be considered as a single diagnostic instrument.

LEVEL OF EVIDENCE

4.

Evaluating the Relationship Between Olfactory Function and Loneliness in Community-Dwelling Individuals: A Cross-sectional Study

BACKGROUND

Olfactory dysfunction (OD) has been reported to impact social interactions. However, the relationship between OD and loneliness has received little attention. The purpose of this study was to determine the association between OD and loneliness, controlling for patient factors.

METHODS

Subjects without otolaryngic complaints were enrolled and olfactory function was assessed using: Sniffin' Sticks test to measure threshold, discrimination and identification (TDI), Questionnaire of Olfactory Disorders Negative Statements (QOD-NS) and 9 - item Olfactory-Visual Analogue Scale (VAS). Loneliness was assessed using the De Jong Gierveld (DJG) and University of California Los Angeles (UCLA) loneliness scales. Bivariate analysis was performed followed by regression analysis, controlling for confounders.

RESULTS

In total, 221 subjects were included with a mean age of 50.5 years (range 20 to 93), 133 (60.2%) females and 161 (72.9%) white. Mean TDI score was 29.3 (7.0) and 49.5% of the cohort was dysosmic. Using DJG, 36.4% of the cohort were classified as lonely, whereas 35.0% were lonely using UCLA. Olfactory measures were significantly associated with DJG, including TDI (β = -0.03, p = 0.050), olfactory discrimination (β = -0.111, p = 0.005), QOD-NS (β = 0.058, p < 0.001) and olfactory-VAS (β = 0.032, p < 0.001). UCLA scores were significantly associated with QOD-NS (PR 1.061 [CI 1.018-1.107], p = 0.005) and olfactory-VAS scores (PR 1.027, [CI 1.007-1.049], p = 0.009). After controlling for confounders, the association between DJG and olfactory discrimination, as well as DJG and olfactory-VAS remained significant.

CONCLUSIONS

In this community-based sample of older adults, both OD and loneliness were common. Those subjects with worse olfactory function were more likely to report loneliness. Further research is necessary to establish causality, as well as explore the role of depression.

Smell dysfunction: a biomarker for COVID-19

BACKGROUND

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), is responsible for the largest pandemic since the 1918 influenza A virus subtype H1N1 influenza outbreak. The symptoms presently recognized by the World Health Organization are cough, fever, tiredness, and difficulty breathing. Patient-reported smell and taste loss has been associated with COVID-19 infection, yet no empirical olfactory testing on a cohort of COVID-19 patients has been performed.

METHODS

The University of Pennsylvania Smell Identification Test (UPSIT), a well-validated 40-odorant test, was administered to 60 confirmed COVID-19 inpatients and 60 age- and sex-matched controls to assess the magnitude and frequency of their olfactory dysfunction. A mixed effects analysis of variance determined whether meaningful differences in test scores existed between the 2 groups and if the test scores were differentially influenced by sex.

RESULTS

Fifty-nine (98%) of the 60 patients exhibited some smell dysfunction (mean [95% CI] UPSIT score: 20.98 [19.47, 22.48]; controls: 34.10 [33.31, 34.88]; p < 0.0001). Thirty-five of the 60 patients (58%) were either anosmic (15/60; 25%) or severely microsmic (20/60; 33%); 16 exhibited moderate microsmia (16/60; 27%), 8 mild microsmia (8/60; 13%), and 1 normosmia (1/60; 2%). Deficits were evident for all 40 UPSIT odorants. No meaningful relationships between the test scores and sex, disease severity, or comorbidities were found.

CONCLUSION

Quantitative smell testing demonstrates that decreased smell function, but not always anosmia, is a major marker for SARS-CoV-2 infection and suggests the possibility that smell testing may help, in some cases, to identify COVID-19 patients in need of early treatment or quarantine.

Smell dysfunction: a biomarker for COVID-19

Background

Severe acute respiratory syndrome‐coronavirus‐2 (SARS‐CoV‐2), the virus that causes coronavirus disease 2019 (COVID‐19), is responsible for the largest pandemic since the 1918 influenza A virus subtype H1N1 influenza outbreak. The symptoms presently recognized by the World Health Organization are cough, fever, tiredness, and difficulty breathing. Patient‐reported smell and taste loss has been associated with COVID‐19 infection, yet no empirical olfactory testing on a cohort of COVID‐19 patients has been performed.

Methods

The University of Pennsylvania Smell Identification Test (UPSIT), a well‐validated 40‐odorant test, was administered to 60 confirmed COVID‐19 inpatients and 60 age‐ and sex‐matched controls to assess the magnitude and frequency of their olfactory dysfunction. A mixed effects analysis of variance determined whether meaningful differences in test scores existed between the 2 groups and if the test scores were differentially influenced by sex.

Results

Fifty‐nine (98%) of the 60 patients exhibited some smell dysfunction (mean [95% CI] UPSIT score: 20.98 [19.47, 22.48]; controls: 34.10 [33.31, 34.88]; p < 0.0001). Thirty‐five of the 60 patients (58%) were either anosmic (15/60; 25%) or severely microsmic (20/60; 33%); 16 exhibited moderate microsmia (16/60; 27%), 8 mild microsmia (8/60; 13%), and 1 normosmia (1/60; 2%). Deficits were evident for all 40 UPSIT odorants. No meaningful relationships between the test scores and sex, disease severity, or comorbidities were found.

Conclusion

Quantitative smell testing demonstrates that decreased smell function, but not always anosmia, is a major marker for SARS‐CoV‐2 infection and suggests the possibility that smell testing may help, in some cases, to identify COVID‐19 patients in need of early treatment or quarantine.

[A study on the quality of life and mental health of sinusitis patients with olfactory disorders]

Objective:The aim of this study is to investigate the incidence of dysosmia in patients with and without nasal polyps, and the impact of dysosmia on the quality of life and mental health in patients with Sinusitis. Method:A total of 105 randomly selected patients with Sinusitis were divided into two groups based on the results of the Sniffin's Sticks olfactory examination: The dysosmia group and the non dysosmia group, the quality of life （Qol） of olfaction quality of life scale and SCL-90 symptom checklist-90（SCL-90） were scored respectively. Result:The incidence of olfactory disorders in chronic sinusitis patients with nasal polyps was significantly higher than those without nasal polyps（χ²=37.133, P<0.001）. The quality of life score of the olfactory disturbance scale the quality of life score of the olfactory disturbance group（26.5±5.9） was significantly higher than that of the non olfactory disturbance group（11.76±3.58）（t=14.30, P<0.0001）. Life quality score（30.2±4.9） of female patients with olfactory dysfunction was significantly higher than that of male patients（22.3±4.0）（P<0.001）, The score of SCL-90 of chronic sinusitis patients with olfactory dysfunction（n=64） is 6.6（6.0-8.0）, while the score of SCL-90 of chronic sinusitis patients without olfactory dysfunction（n=41） is 7.0（6.2-7.6）, and there was no significant difference between the two groups（P>0.05）. Conclusion:The risk of dysosmia in patients with Sinusitis polyps was significantly higher than that in patients without nasal polyps, and the quality of life in patients with Sinusitis was significantly lower than that in patients without sinusitis, women also had a greater impact on their quality of life than men, and Sinusitis patients with dysosmia had no significant impact on their mental health.

[Olfactory dysfunction and COVID-19 - current state of the problem]

According to data from China, Italy, South Korea, Iran, USA, France, from 17 to 87% of patients with confirmed COVID-19 have a violation of smell and taste. Acute sudden anosmia may precede symptoms such as cough and shortness of breath. Also, hypo/anosmia may be the only symptom of mild COVID-19. European, American and domestic associations of otorhinolaryngologists warn that, these patients may be hidden carriers that contribute to the spread of COVID-19 infection, because they have no indications for testing for the virus and self-isolation. Including anosmia in the criteria for self-isolation can help prevent the spread of COVID-19 infection. In addition, it would signal the medical staff to use full personal protection when dealing with these patients and help reduce the number of infected doctors. It is known that olfactory disorders can be conductive, perceptual or mixed. Olfactory disturbances in COVID-19 are most likely of a perceptual nature. Although, at the moment, there is insufficient data to determine the exact mechanisms of the onset of anosmia in patients diagnosed with COVID-19, however, there are studies that confirm these or those theories. The article provides an overview of the data available in the literature on this topic.

Correlation of mucus inflammatory proteins and olfaction in chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is one of the most common causes of olfactory loss, but the pathophysiology underlying olfactory dysfunction in CRS has not been fully elucidated. Previous studies found correlations between olfactory cleft (OC) inflammatory cytokines/chemokines and olfaction in CRS. The purpose of this study was to evaluate the relationship between OC mucus inflammatory proteins and olfaction in a multi-institutional cohort.

METHODS

Adults with CRS were prospectively recruited. Demographics, comorbidities, olfactory assessment (Sniffin' Sticks), computed tomography (CT), and OC mucus for protein analysis were collected. Statistical analysis was performed to determine associations between olfactory function, OC mucus protein concentrations, and CT opacification.

RESULTS

Sixty-two patients were enrolled in the study, with an average age of 48.2 (standard deviation, 16.2) years, and 56.5% were female and 59.7% were classified as CRS with nasal polyps (CRSwNP). Ten of 26 OC mucus proteins were significantly correlated with threshold, discrimination, and identification (TDI) scores and OC opacification. Subgroup analysis by polyp status revealed that, within the CRSwNP group, C-C motif ligand 2 (CCL2), interleukin-5 (IL-5), IL-6, IL-13, IL-10, IL-9, tumor necrosis factor-α (TNF-α), CCL5, and CCL11 were significantly correlated with olfaction. For CRS without nasal polyps (CRSsNP), only C-X-C ligand 5 (CXCL5) showed a correlation. In CRSwNP, IL-6, IL-10, vascular endothelial growth factor-A, and immunoglobulin E (IgE) correlated with OC opacification, whereas, in CRSsNP, only CXCL5 showed a correlation. OC mucus proteins and Lund-Mackay score correlated only in the CRSsNP group (CXCL5, IL-5, IL-13, IgE).

CONCLUSION

Several OC mucus proteins have been found to correlate with olfactory function and OC opacification. The profile of OC mucus proteins differs between CRSsNP and CRSwNP subgroups, suggesting different mechanisms between groups, but further study is required.

Adherence and Efficacy of Olfactory Training as a Treatment for Persistent Olfactory Loss

Background

Among emerging therapies, olfactory training (OT) has been proposed as a potential treatment for persistent olfactory loss. This treatment has been suggested to improve olfactory function via sensorineural modulation from repeated odor exposure. However, due to the long treatment period that is required, many patients discontinue the treatment or do not follow the treatment regimen appropriately, potentially biasing estimates of treatment success. Moreover, spontaneous improvement is known to occur without any interventions.

Objectives

We evaluated both the adherence rates and the efficacy of OT in patients with persistent postinfectious, posttraumatic, or idiopathic olfactory loss.

Methods

Prospective observational study. Twenty-five patients with persistent olfactory loss underwent OT. Protocol adherence and olfactory function (scores on the University of Pennsylvania Smell Identification Test or UPSIT) were assessed 3 and 6 months after the initiation of treatment. A minimum improvement of 5 UPSIT points was considered clinically significant and adherence throughout the study.

Results

The adherence rate of the patients after 3 months was 88% and after 6 months was 56%. The corresponding percentages of clinical improvement were 23.5% and 25%. There was no relation of age, sex, time of olfactory loss, race, the degree of olfactory loss, etiology, education, and type of training to the adherence rate or treatment efficacy.

Conclusions

In this patient population, adherence to training remained high in the first 3 months of OT but declined moderately thereafter. The observed prevalence and degree of improvement were similar to that reported a number of studies, including some studies whose patients did not receive OT.

The Use of Imaging to Detect Intracranial Tumors in Idiopathic Olfactory Dysfunction: A Systematic Review

Objectives

To review the literature regarding the use of intracranial imaging as a screening tool for idiopathic olfactory loss (IOL) and to review the incidence of identifying a sinonasal or intracranial neoplasm as a result of intracranial imaging.

Methods

A systematic review of published English-language literature was performed using PubMed, Ovid MEDLINE, Scopus, and Cochrane databases.

Results

Of the 694 available abstracts, 5 met inclusion criteria for this review. Out of 470 eligible patients, intracranial imaging identified tumors causing IOL in 8 patients (1.7%). Tumor detection rates ranged from 0% to 4.9%. Of the 470 eligible patients, intracranial imaging detected intracranial or sinonasal pathology, excluding tumors, causing IOL in 53 patients (11%). The findings ranged from 0.77% to 23%. Of the 604 eligible IOL patients, 470 (81%) underwent intracranial imaging, ranging from 53% to 100%.

Conclusions

In most cases, diagnostic imaging in IOL patients is frequently ordered. This study finds computed tomography or magnetic resonance imaging to be an important recommendation given to all patients with IOL. Although the overall rate of detecting tumor from diagnostic imaging is low, it is important to offer diagnostic imaging to this subset of patients to avoid missing tumors at an early stage.

Olfactory cleft and sinus opacification differentially impact olfaction in chronic rhinosinusitis

OBJECTIVES

Prior studies have indicated that olfactory cleft (OC) opacification correlates with olfaction in patients with chronic rhinosinusitis (CRS). However, the results have been unclear in patients without polyps. The purpose of this study was to further explore the relationship between OC opacification, sinus opacification, and olfactory function in patients with CRS.

METHODS

One hundred and forty-eight patients with CRS were prospectively enrolled across five institutions. Olfactory function was evaluated using the Sniffin' Sticks tests (Burghardt, Wedel, Germany) and the 17-item Questionnaire of Olfactory Disorders (QOD-NS). Computed tomography (CT) scans for each patient were acquired and Lund-Mackay scores recorded. Opacification of the OC was determined using OsiriX MD (Pixmeo, Bernex, Switzerland) and correlated with olfaction scores.

RESULTS

A total of 148 CRS patients, 73 CRS without nasal polyps (CRSsNP) and 75 CRS with nasal polyps (CRSwNP), as well as 30 control subjects were enrolled. Overall OC opacification averaged 63.7% in CRS patients and 47.1% in control subjects (P < 0.001). In the overall cohort, OC opacification significantly correlated with threshold, discrimination, and identification (TDI) (r = -0.520; P < 0.001) and QOD-NS scores (r = 0.374; P < 0.001). CRSwNP patients demonstrated a significant correlation between OC opacification and TDI scores (r = -0.464; P < 0.001) but not the CRSsNP group (r = -0.143; P = 0.229). Lund-Mackay score correlated with TDI in both the CRSsNP (r = -0.300; P = 0.010) and CRSwNP (r = -0.271; P = 0.019) groups.

CONCLUSION

CT opacification is associated with olfactory dysfunction differentially based on nasal polyp status. Smell loss in CRSwNP correlated with both OC opacification and Lund-Mackay score, whereas CRSsNP correlated only with Lund-Mackay score, indicating different relationships between olfactory function and local inflammatory processes in these disorders.

LEVEL OF EVIDENCE

2 Laryngoscope, 130:2311-2318, 2020.