Olfactory Disorders Research Articles

The effectiveness of cerebrolysin, a multi-modal neurotrophic factor, for treatment of post-covid-19 persistent olfactory, gustatory and trigeminal chemosensory dysfunctions: a randomized clinical trial

ABSTRACTBackgroundThis trial aimed to monitor the outcomes of persistent post-covid-19 smell and taste disorders after cerebrolysin therapy, a NTF, and olfactory and gustatory trainings.Research design and methodsThis was a prospective randomized trial. It included 250 patients (male = 93, female = 157; age: 31.3 ± 8.9 years). Patients were randomized into group 1 (n = 150): received cerebrolysin [5 ml/d (IM), 5d/week] and practiced olfactory and gustatory trainings, and group 2 (n = 100): practiced olfactory and gustatory trainings only, for ≥ 8–24 weeks. Measures of outcomes were: a clinical questionnaire; sniffin’ odor, taste and flavor identification tests; and global rating scales for smell and taste.ResultsThe duration of disorders was 11.7 ± 3.7mo (range: 6-24mo). The majority (n = 167; 66.8%) developed parosmia within months (3.6 ± 2.7mo) after anosmia. Objective testing showed anosmia in all and taste, flavor, and trigeminal sensory losses in 18% (n = 45). Analyses for secondary outcome were done on 202 patients (group 1 = 130; group 2 = 72). Recovery was complete in 61.5% (n = 80) with cerebrolysin therapy and partial in 17% (n = 22). There was no recovery with trainings only. There were no predictors for recovery.ConclusionsCerebrolysin had fast, promising, and constant effect, with cure rate of > 60%. This might be due to its ability to initiate and enhance neuronal regeneration and reorganization of sensory epithelia.Trial registrationNCT04830943.

Bi-directional nasal drug delivery systems: A scoping review of nasal particle deposition patterns and clinical application.

To compare the deposition patterns within the nasal cavity between the bi-directional and unilateral nasal delivery systems. And to summarize the clinical application of the bi-directional nasal drug delivery devices. PubMed, Cochrane Library, Embase, and Web of Science databases. A scoping review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). We included studies exploring patterns and influencing factors of particle depositions within the nasal cavity among patients, healthy controls, and nose cast models using the bi-directional and unilateral nasal delivery system. The clinical application of the bi-directional delivery devices was also summarized. A total of 24 studies were included in this review. Bi-directional nasal delivery systems utilize forced exhalation to power the delivery of drugs to deeper areas of the nasal cavity and paranasal sinuses. Unilateral nasal delivery systems included traditional liquid spray pumps, the aerosol mask system, nebulization, and conventional nasal inhalation. Compared with unilateral delivery systems, the bi-directional nasal delivery system provided a more extensive and efficient nasal deposition in the nasal cavity, especially in the olfactory cleft, without lung deposition. Several parameters, including particle size, pulsatile flow, and nasal geometry, could significantly influence nasal deposition. The bi-directional nasal delivery system enables better delivery of steroids or sumatriptan to the sinonasal cavity's high and deep target sites. This bi-directional delivery device demonstrated an effective and well-tolerated treatment that produced high drug utilization, rapid absorption, and sustained symptom improvement among patients with chronic rhinosinusitis (CRS) or migraine. The bi-directional nasal drug delivery systems demonstrated significantly higher drug deposition in superior and posterior regions of the nasal cavity than unilateral nasal delivery systems. Further studies should explore its potential role in delivering drugs to the olfactory cleft among patients with olfactory disorders and central nervous system diseases. N/A.

Odors determition among the population of the regions of the Russian Federation: Cross-sectional study

Introduction. Currently, the main way to assess olfactory disorders is olfactory tests. A necessary condition for adequate diagnosis is that the odors used in tests correspond to the sociocultural characteristics of the population; the identified flavors must be well recognizable. The use of unadapted tests distorts the results and leads to a false diagnosis of the pathology in a person with a normal sense of smell. The research for identification of the most known odors is an important stage in validation of the existing tests and in the development of new ones.Aim. Determination odors in various regions of the Russian Federation.Materials and methods: 3000 people from 8 federal districts of the Russian Federation took part in the study. This study was conducted using a questionnaire based on a Likert scale. The subject was required to assess his level of familiarity with each odor from the proposed list, assigning it a score from 1 to 5. In total, the questionnaire listed 100 names, including 16 names of odors, the standard set of the 3rd stage (assessment of identification ability) Sniffin’ Sticks Test, 40 names of odorants of the University of Pennsylvania Psychophysical Test (UPSIT) and 44 odors found in the everyday life of the population of our country.Results. In the first 25 positions of the most recognizable smells, in descending order, there are: 1) coffee; 2) orange; 3) garlic; bleach; 5) mint; 6) tobacco smoke; 7) gasoline; 8) tangerine; 9) lemon; 10) smoke from a fire; 11) onion; 12) strawberry; 13) apple; 14) alcohol; 15) fish; 16) mown grass; 17) chocolate; 18) acetone; 19) banana; 20) hot bread; 21) rose; 22) lilac; 23) melon; 24) watermelon; 25) cucumber. Among the 16 odors of the 3rd stage of identification of the standard set “Sniffin’ Sticks Test” – 43.75% are included in the first 16 positions of recognizable odors of the Russian rating, and among the 40 odors of the UPSIT olfactory test – 52.5%.Conclusions: This study showed which odors are well recognized by the Russian population and confirmed that cultural adaptation as a necessary procedure before routine use of olfactory tests.

Probing long COVID through a proteomic lens: a comprehensive two-year longitudinal cohort study of hospitalised survivors

As a debilitating condition that can impact a whole spectrum of people and involve multi-organ systems, long COVID has aroused the most attention than ever. However, mechanisms of long COVID are not clearly understood, and underlying biomarkers that can affect the long-term consequences of COVID-19 are paramount to be identified. Participants for the current study were from a cohort study of COVID-19 survivors discharged from hospital between Jan 7, and May 29, 2020. We profiled the proteomic of plasma samples from hospitalised COVID-19 survivors at 6-month, 1-year, and 2-year after symptom onset and age and sex matched healthy controls. Fold-change of >2 or <0.5, and false-discovery rate adjusted P value of 0.05 were used to filter differentially expressed proteins (DEPs). In-genuity pathway analysis was performed to explore the down-stream effects in the dataset of significantly up- or down-regulated proteins. Proteins were integrated with long-term consequences of COVID-19 survivors to explore potential biomarkers of long COVID. The proteomic of 709 plasma samples from 181 COVID-19 survivors and 181 matched healthy controls was profiled. In both COVID-19 and control group, 114 (63%) were male. The results indicated four major recovery modes of biological processes. Pathways related to cell-matrix interactions and cytoskeletal remodeling and hypertrophic cardiomyopathy and dilated cardiomyopathy pathways recovered relatively earlier which was before 1-year after infection. Majority of immune response pathways, complement and coagulation cascade, and cholesterol metabolism returned to similar status of matched healthy controls later but before 2-year after infection. Fc receptor signaling pathway still did not return to status similar to healthy controls at 2-year follow-up. Pathways related to neuron generation and differentiation showed persistent suppression across 2-year after infection. Among 98 DEPs from the above pathways, evidence was found for association of 11 proteins with lung function recovery, with the associations consistent at two consecutive or all three follow-ups. These proteins were mainly enriched in complement and coagulation (COMP, PLG, SERPINE1, SRGN, COL1A1, FLNA, and APOE) and hypertrophic/dilated cardiomyopathy (TPM2, TPM1, and AGT) pathways. Two DEPs (APOA4 and LRP1) involved in both neuron and cholesterol pathways showed associations with smell disorder. The study findings provided molecular insights into potential mechanism of long COVID, and put forward biomarkers for more precise intervention to reduce burden of long COVID. National Natural Science Foundation of China; Chinese Academy of Medical Sciences (CAMS) Innovation Fund for Medical Sciences; Clinical Research Operating Fund of Central High Level Hospitals; the Talent Program of the Chinese Academy of Medical Science; Training Program of the Big Science Strategy Plan; Ministry of Science and Technology of the People's Republic of China; New Cornerstone Science Foundation; Peking Union Medical College Education Foundation; Research Funds from Health@InnoHK Program.

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.

A new computed tomography protocol to assess the olfactory cleft

INTRODUCTION: The olfactory cleft is a region of significant importance within the nasal cavity, given the heightened focus on olfactory disorders in recent years. It is considered a 3-dimensional space that starts at the most anterior olfactory filament and ends just anteriorly to the sphenoid sinus. This study aimed to outline the profile of the olfactory cleft as an anatomical area of extreme relevance in the diagnosis of diseases of the nose, paranasal sinuses and olfactory disorders. The aim to establish parameters of radiological normality for the olfactory cleft enables us to recognize and differentiate nasal disorders by identifying the widening or narrowing of the olfactory cleft during the preoperative assessment, thus facilitating the planning of the optimal treatment. This supports a theory about the evolution and development of the nose (Evo Devo Theory) that shows the olfactory nose (ethmoid and olfactory cleft) represents the seat of most diseases of the nose and paranasal sinuses. MATERIALS AND METHODS: 700 random CT scans of the nose and sinuses have been studied. A homogeneous group of CT scans of patients without paranasal sinus diseases were included in this study, seeking to define a reference anatomical measure as a criterion for tomographic normality. Measurements of the olfactory cleft were taken in the lateral-lateral direction between the middle concha and the septum on each side of the nose cavity at three specific anatomical points in the anterior skull base in the anteroposterior direction, corresponding to the beginning, middle and end of the olfactory cleft. For data analysis, exploratory statistical techniques have been used that allowed a better visualization of the general characteristics of the data. The appropriate statstical analysis was performed using Statistical Package for Social Sciences (SPSS). RESULTS: According to the statistical analysis performed, the reference values that were found evaluating and studying the three points were: at the first point - First Olfactory Neuron Point (FONP) – was 1.3 to 2.1 mm, at the second point - Middle Point (MP) was 1.1 to 1.6 mm, and at the third point – Sphenoethmoidal recess point (SERP) was 1.1 to 1.8 mm. The average in the first point was 1.78 mm, while in the second and third points were 1.41 and 1.48 mm, respectively. CONCLUSION: It is concluded that the tomographic olfactory cleft reference values are respectively: at the first point – First Olfactory Neuron Point- 1.3 to 2.1 mm, at the second point - Middle Point - 1.1 to 1.6 mm, and at the third point – Sphenoethmoidal recess point -1.1 to 1.8 mm.

Predictive factors of involuntary weight loss in patients with smell and taste disorders.

Chemosensory dysfunction (olfaction, taste, and trigeminal) affects quality of life, potentially impacting eating behaviors. We investigated which factors are associated with weight loss in patients with smell and taste disorders. Retrospective study of consecutive adult patients seen in the smell and taste clinic during a 10-year period. Patients were asked about smell, flavor and taste impairment. Psychophysically, smell was assessed with Sniffin' Sticks, flavor with a retronasal test, and taste with Taste Strips. A total of 554 patients (313 females) were included with a median age of 51 years (IQR 23). Seventy-six (13.7%) reported involuntary weight loss (median 6 kg, IQR 6) due to chemosensory disorders. The odds of losing weight were 2.1 times higher when patients reported subjective changes in flavor perception. Parosmia was a significant predictor of weight loss. Patients with symptoms lasting longer than two years were less likely to present with weight loss. Post-traumatic chemosensory dysfunction was a significant predictor of losing weight. On psychophysical testing, the probability of a patient losing weight increased by 8% for every 1-unit reduction in Taste Strips score. Factors associated with weight loss were self-reported changes in flavor perception, parosmia, duration of symptoms for less than two years, head injury, and psychophysically measured low Taste Strips score. These data help to identify patients at risk of weight loss from smell or taste impairment.

The predicting role of postoperative changes in self-reported symptoms in patients with recurrence eosinophilic chronic sinusitis with nasal polyps

Objective:To investigate whether changes in postoperative symptoms and signs in patients can predict the recurrence of ECRS after nasal endoscopic sinus surgery. Methods:A total of 70 adult patients with ECRS were enrolled for ESS surgery from June 2020 to March 2022 in a single center. There were 50 males and 20 females, with an average age of （46.9±14.5） years. Follow-up after ESS was at least 52 weeks. Patients undergo peripheral blood tests, CT of the sinuses, olfactory T&T test, visual analogue scale of symptoms（VAS）, and endoscopic scoring. Results:VAS scores and endoscopic scores were analyzed at preoperative and 6th week, 12th week, 24th week and 52th week postoperative. After 12th week postoperatively, there was a clear correlation between symptom scores and endoscopic scores. Moreover, olfactory disorder and nasal discharge were the two most obvious symptoms. There were differences in the expression of multiple preoperative clinical inflammatory indicators between the symptom-controled group and the symptom-uncontrolled group（previous surgical history, concomitant asthma, nasal smear eosinophil, serum EOS%, total IgE, CT score, olfactory score, and symptom score, all with P<0.05）, while there was no difference in baseline endoscopic score（P>0.05）. At 12th week postoperative, the two groups of patients showed significant differences in both symptom scores and endoscopic scores. The symptoms and endoscopic score at the 12th week point of follow-up were used as predictive indicators for recurrence, with sensitivity and specificity of 62.5% and 83.3%, respectively. Conclusion:The changes in postoperative symptom score and endoscopic score in ECRSwNP patients indicated that the recurred ECRS. In the symptom-uncontrolled group, symptomatic and endoscopic scores showed consistent increased scores; In the symptom-controlled group, conflicting results between increased endoscopic scores and stable symptoms suggest that the presence of asymptomatic recurrence must be considered. The changes in symptoms and signs at the 12th week point of follow-up can serve as clinical indicators for preventing disease recurrence.

Olfactory disorders in childhood: A comparative study of olfaction in children with adenoid hyperplasia versus a control group and the postoperative effects of adenoidectomy with respect to olfactory ability.

Hyposmia in childhood is poorly characterized. The "U-Sniff Test", validated for children with anosmia, can be used to objectify olfactory impairment but has not been used to distinguish between hyposmia and normosmia. Therefore, we investigated children with enlarged adenoids with respect to hyposmia, its correlation with adenoid size, and the sensitivity of questionnaires to predict olfactory impairment. In a prospective comparison, olfaction was assessed by "U-Sniff Test" (score 0-12; <8 hyposmia) in 41 children (5-18 years) with adenoid hyperplasia and compared with 196 children without any respiratory affection (control) after exclusion of previous SARS-Cov2-infection from December 2020 to December 2021. ENT-related complaints were collected using a self-designed questionnaire. We were able to include 13 children in a follow-up examination to compare preoperative performance in the "U-Sniff Test" with postoperative outcome after adenoidectomy. chi-square-test (p<0.05), odds-ratio, Spearman's rho, ROC-, cluster analysis. Severe hyposmia was present in 36.6% of children with adenoid-hyperplasia compared to 3.1% of the control-group. Adenoid-children scored significantly more often between 8 and 10 points (58.5%) than the control (31.6%; p<0.01). Adenoid size and olfactory performance correlate significantly (r: 0.83; CI -0.89 … -0.72). Hyposmia in the adenoid group is characterized predominately by loss of the odors banana, butter and rose. None of children with hyposmia or parents reported impaired olfactory performance. Postoperatively, olfactory function improved significantly in 85% of cases (p 0.01, SD ± 1.71, Δ3.54points). Questionnaires are insufficient to detect hyposmia in this cohort. In contrast, the "U-Sniff Test" detects even reduced olfactory performance without reaching the cut-off value, which represents the majority of test results in the adenoid group. Therefore, we recommend the classification of moderate hyposmia (8-10 points) to be included for our study population.

Olfactory loss in people with cystic fibrosis: Community perceptions and impact.

Olfactory dysfunction (OD) is prevalent in people with cystic fibrosis (PwCF) and can negatively impact quality-of-life (QOL). This study evaluated perceptions of OD, investigated how OD impacts QOL, and assessed willingness to participate in OD research among the CF community. A 21-question survey was distributed through the CF Foundation's Community Voice program in 2023. The survey included questions on olfaction and interest in research. The Brief Questionnaire of Olfactory Disorders (BQOD), a validated person-reported outcome measure to assess QOL, was included. Seventy-six responses were received. Overall, 91% (69/76) reported olfactory problems. Mean BQOD score was 5.0 (standard deviation=4.8), indicating olfactory QOL impairment was present. Ninety-five percent (72/76) reported research on OD is worthwhile and were willing to participate in research. Among PwCF, OD and olfactory-specific QOL impairments are prevalent. There is strong interest and willingness to participate in OD research among the CF community.

SARS-CoV-2 Spike Protein S1 Domain Accelerates α-Synuclein Phosphorylation and Aggregation in Cellular Models of Synucleinopathy.

The 2019 novel coronavirus disease (COVID-19) is an infectious disease that began to spread globally since 2019. Some COVID-19 patients have neurological complications, such as olfactory disorders and movement disorders, which coincide with the symptoms of Parkinson's disease (PD). Increasing imaging and autopsy evidence supports that the density of dopaminergic neurons in the nigrostriatal pathway is damaged in some COVID-19 patients. However, the underlying mechanism that causes PD-like symptoms remains unclear. PD is an age-related neurodegenerative disease with Lewy bodies (LBs) as its histopathologic feature. The main component of LBs is abnormally aggregated α-synuclein (α-syn). The prion-like propagation of α-syn aggregates plays a key role in the onset and progression of PD. The spike protein (S protein) of SARS-CoV-2 is a heparin-binding protein that mediates the entry of the virus into host cells. Here we found that the S1 domain interacts with α-syn and promotes α-syn aggregation. The S1 domain induces mitochondrial dysfunction, oxidative stress, and cytotoxicity. The S1-seeded α-syn fibrils show enhanced seeding activity and induce synaptic damage and cytotoxicity. Thus, the S1 domain of SARS-CoV-2 promotes the aggregation of α-syn in the cellular model of synucleinopathy and may contribute to the pathogenesis of PD.

Post-COVID-19 Olfactory and Gustatory Dysfunction: Photobiomodulation Therapy as a Treatment Option in a Series of Cases

Introduction: Coronaviruses patients may develop various neurological complications, including loss of smell and taste. Rehabilitation programs should be considered for patients with disabilities lasting longer than two weeks. The present pilot study evaluated photobiomodulation therapy (PBMT) as a treatment option for olfactory and gustatory dysfunctions. Case Representation: The study included six patients with coronavirus disease with olfactory and gustatory complaints who were part of a cohort of 172 coronavirus disease patients monitored for late neurological manifestations. Olfactory and gustatory functions were evaluated using visual analog scales applied at baseline, end, and 6 months after treatment. 36-item Short-Form General Health Survey and a questionnaire containing closed questions were also administered. All scales were applied by a researcher blinded to the results of the given intervention. An intranasal PBMT protocol was applied, with 16 laser sessions performed twice a week at a 48-hour interval. Results: A statistically significant difference was observed between the medians of the visual analogue scale scores for olfactory and gustatory disorders before, after, and six months later. The medians of the physical role, social functioning, general health, and emotional role SF-36 domains were higher after treatment, suggesting improved quality of life. Conclusion: The results observed in this study suggest that PBMT can be an effective resource for patients with long-term COVID-19.

Persistent olfactory impairment after COVID-19-recommendations of the Working Group on Olfactology and Gustology of the German Society of Oto-rhino-laryngology, Head and Neck Surgery

This article does not intend to comprehensively review the existing literature on coronavirus disease 2019 (COVID-19)-associated smell disorders, but aims to summarize scientific evidence for otorhinolaryngological practice and provide recommendations for diagnosis and treatment of persistent smell disorders following COVID-19.

Smell, taste and chemesthesis disorders in patients with the SARS-CoV-2 during Omicron variant pandemic in China

Chemosensory disorders (including smell, taste and chemesthesis) are among the established symptoms of COVID-19 infection; however, new data indicate that the changes in chemosensory sensation caused by COVID-19 may differ among populations and COVID-19 variants. To date, few studies have focused on the influence of the SARS-CoV-2 Omicron variant on qualitative changes and quantitative reductions in chemosensory function in China. We conducted a cross-sectional study of patients with COVID-19 caused by the Omicron variant, to investigate the prevalence of chemosensory disorders and chemosensory function before and during infection, using an online questionnaire. A total of 1245 patients with COVID-19 completed the survey. The prevalence rates of smell, taste, and chemesthesis disorders were 69.2%, 67.7%, and 31.4%, respectively. Our data indicate that sex, age, smoking, and COVID-19-related symptoms, such as lack of appetite, dyspnea, and fatigue, may be associated with chemosensory disorders during COVID-19. Self-rating of chemosensory function revealed that patients experienced a general decline in smell, taste, and chemesthesis function. Further longitudinal research studies are needed to generate additional data based on objective assessment and investigate the factors influencing chemosensory function in COVID-19.

Position paper on olfactory dysfunction: 2023

Since publication of the original Position Paper on Olfactory Dysfunction in 2017 (PPOD-17), the personal and societal burden of olfactory disorders has come sharply into focus through the lens of the COVID-19 pandemic. Clinicians, scientists and the public are now more aware of the importance of olfaction, and the impact of its dysfunction on quality of life, nutrition, social relationships and mental health. Accordingly, new basic, translational and clinical research has resulted in significant progress since the PPOD-17. In this updated document, we present and discuss currently available evidence for the diagnosis and management of olfactory dysfunction. Major updates to the current version include, amongst others: new recommendations on olfactory related terminology; new imaging recommendations; new sections on qualitative OD and COVID-19 OD; updated management section. Recommendations were agreed by all co-authors using a modified Delphi process. We have provided an overview of current evidence and expert-agreed recommendations for the definition, investigation, and management of OD. As for our original Position Paper, we hope that this updated document will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency, and generalisability of work in this field.

Alcohol Sniff Test (AST): An Important Tool for Screening Post-Viral Olfactory Loss in Acute Flu-Like Dysfunction.

Olfactory disorders have a significant impact on patients' quality of life but are often underestimated in clinical practice. Upper respiratory tract infections (URTIs) are a common cause of olfactory loss. While most cases of olfactory loss due to URTIs are conductive and reversible, post-viral olfactory dysfunction (PVOD) persists despite symptom improvement. PVOD is attributed to damage to the olfactory epithelium and nerves or central olfactory pathway lesions. The Alcohol Sniff Test (AST) has been proposed as a tool to assess olfactory function in the acute phase and aid in differentiating PVOD from conductive disorders. This study aims to evaluate the effectiveness of the AST as a predictor of post-viral olfactory loss in patients with flu-like syndrome. An observational cross-sectional study was conducted among employees with flu-like syndrome at a tertiary hospital. Three groups were formed: flu-like syndrome with conductive disorder without COVID-19 (PVOD-), flu-like syndrome with neurosensory and/or central disorder due to COVID-19 (PVOD +), and an asymptomatic control group. The Alcohol Sniff Test was performed to assess olfactory function. Statistical analysis was conducted to evaluate the AST's performance. For a cut off of 10cm, 88.57% of PVOD + patients and 60.53% of PVOD - patients showed AST alteration, respectively (p = 0.013, OR = 5.05, 95% CI [1.48-17.25]). There was a statistically significant difference in the mean distance between the PVOD + group (4.35 ± 4.1cm) and the control group (20 ± 4.33cm) (p < 0.05). This relationship was also observed between the PVOD + and PVOD- groups (9cm ± 7.5) (p < 0.05) and between the PVOD- and control groups (p < 0.05). For a cut off of 10cm, the AST showed a sensitivity of 88% and specificity of 41%, resulting in an Odds Ratio of 9.7 (95% CI 3.3-28.1) (p < 0.001) and a Positive Predictive Value of 69.4% for PVOD. PVOD, including cases associated with COVID-19, is a prevalent cause of olfactory loss. The Alcohol Sniff Test demonstrated promising results in identifying PVOD in patients with flu-like syndrome. The test's simplicity and accessibility make it a valuable tool for early screening and identifying individuals who may benefit from prompt treatment. The Alcohol Sniff Test (AST) shows potential as an effective tool for screening post-viral olfactory loss in patients with flu-like syndrome. It can aid in early identification of PVOD cases and facilitate timely interventions to reduce the likelihood of persistent hyposmia.

A Comparative Analysis of the Incidence, Severity and Duration of Smell and Taste Loss in COVID-19 Cases Versus Non-COVID-19 Cases: A Longitudinal Cohort Study.

The COVID-19 pandemic has highlighted the relevance of olfactory and gustatory disorders. However, these symptoms can also be caused by various other factors. In this study we aimed to compare the incidence, severity and duration between COVID-19 related and non-COVID-19 related smell and taste disorders. We conducted a longitudinal cohort study using data from the Dutch biobank Lifelines, which includes over 167,000 participants. The data were collected using 27 questionnaires distributed between March 2020 and May 2022. Descriptive data and the incidence of smell and taste loss in both groups were calculated. To visualize the proportion of severity rates of symptoms, a heatmap was created. A survival analysis was conducted and presented in a reversed Kaplan-Meier curve to show the probability of having persistent smell loss in both groups. The study included 235,722 participants. The incidence of smell loss was higher in the COVID-19 positive group, when compared to the COVID-19 negative group. We found varying degrees of symptom severity in COVID-19 positive cases, ranging from mild to severe, while non-COVID-19 related cases mostly reported mild symptoms. The survival outcome for smell and taste loss was 0.12 (SE 0.03, 95% CI 0.07-0.21) in COVID-19 related cases, and was 0.17 (SE 0.03, 95% CI 0.12-0.24) in cases related to other causes. This study reveals a higher incidence and severity of smell and taste loss in individuals with COVID-19 compared to non-COVID-19 related cases. However, non-COVID-19 related smell and taste loss tend to have a longer duration.

Relationship between clinical symptom profiles and COVID-19 infection status during Delta-dominant period versus Omicron-dominant period—analysis of real-world data collected in Hiroshima Prefecture, Japan

ObjectivesThe present study investigates the diagnosis and prediction of COVID-19 based on clinical symptoms, and corresponding difference between the Delta- and Omicron-dominant periods, using data collected at polymerase chain reaction (PCR) centers in Hiroshima Prefecture, Japan. MethodsData was collected using a J-SPEED-style COVID-19 standard data collection form. The analysis was done in two directions: calculating the likelihood ratio that clinical symptoms will manifest in "infected" versus "non-infected" individuals and calculating the diagnostic odds ratio (OR) of infection for those who have symptoms compared to those without symptoms. ResultsCOVID-19 was more strongly associated with smell and taste disorders during the Delta-dominant period, and muscle pain during the Omicron-dominant period. An age-specific analysis of likelihood and diagnostic ORs found cold-like symptoms had the lowest ability to diagnose COVID-19, and the lowest predictability of COVID-19 with children during both periods. The likelihood and diagnostic ORs of other symptoms for COVID-19 were highest in adults and lowest in those over 65. ConclusionSymptoms are an important indicator of COVID-19, but the association between specific symptoms and COVID-19 is dependent on the dominant variant of the virus.

The first quick olfactory test specific for Alzheimer's disease and French culture.

Olfactory identification disorder is considered a promising early biomarker of Alzheimer's disease (AD). The QUICK TODA2 can be used as a short olfactory screening tool specific for French AD patients. The selection of AD specific odorants and the design of this screening were the main objectives of this twofold study. In study 1, the TODA2 olfactory test was administered to 43 mild-AD patients and 45 healthy controls (HC) in five memory centres in France. The selection of AD specific odorants was based on the differences in the proportion of correct answers and in the threshold means between AD and HC groups. In study 2, another set of 19 mild-AD patient were included at the memory centre of Nice Hospital. All participants completed the olfactory assessment pipeline including the QUICK TODA2, TODA2 and Sniffin' Sticks Identification sub-Test (SST-i). The individual scores of the three tests were correlated. In study 1, ten TODA2 odorants could significantly differentiate AD participants from controls. We selected the six most AD-sensitive items to design the QUICK TODA2. In study 2, we reported strong significant correlations between QUICK TODA2 and TODA2 (ρ(17) = 0.68, p = 0.001**), SST-i and QUICK TODA2 (ρ(17) = 0.65, p = 0.002**), SST-i and TODA2 (ρ(17) = 0.57, p = 0.01*). QUICK TODA2 is a 5-min non-invasive olfactory AD screening tool dedicated to French culture. Its results converge with those of longer, validated olfactory tests. It could be used as a quick screening tool in the general daily practice before an extensive assessment in memory centres.

Olfaction-associated quality of life: Polish adaptation and validation of a Questionnaire of Olfactory Disorders (QOD-PL) in patients with chronic rhinosinusitis.

The focus on health-related quality of life (HRQOL) in medical research is becoming more and more intensive, with attention being paid to the patient's subjective feelings and assessment of one's health status. Smell disorders can significantly impact human life. The Questionnaire of Olfactory Disorders (QOD) is a self-monitoring questionnaire that provides subjective information about olfactory disorders. This study aimed to check the reliability and validation of the Polish version of QOD (QOD-PL) for use in patients with olfactory impairment in Poland. A total of 158 patients (76 females, mean age (Mage) 45.97 ±16.37 years), suffering from chronic rhinosinusitis (CRS), whose olfactory function was measured using the Sniffin' Sticks test (SST), were studied. All patients completed 3 validated questionnaires: Importance of Olfaction (IO), Sino-Nasal Outcome Test-22 (SNOT-22) and QOD-PL. Internal consistency and test-retest reliability of the entire QOD-PL scale were good (Cronbach's α = 0.88). The convergent validity of the QOD-PL and its subscales correlated with IO and SNOT-22. The life quality statements in the QOD-PL (QOD-PL-LQ) score, its negative statements, and the mean score for VAS scales were significantly and positively correlated with all symptoms measured with SNOT-22 and none of the IO scales. The QOD-PL is a reliable, valid and important tool for assessing HRQOL in patients with olfactory disorders. However, it is important to note that not all of its subscales can be considered and interpreted separately.