Predictors of Subjective Olfactory Dysfunction and Sinonasal Quality-of-Life After Endoscopic Transsphenoidal Pituitary Surgery

BACKGROUND

This is the largest study in North America investigating olfactory outcomes after pituitary surgery to date.

OBJECTIVE

Characterize factors associated with subjective olfactory dysfunction (OD) and worsened sinonasal quality-of-life (QOL) after endoscopic TSA.

METHODS

Patients undergoing primary TSA for secreting and non-secreting pituitary adenomas between 2017 and 2021 with pre- and post-operative SNOT-22 scores were included. Subjective OD was determined by the smell/taste dysfunction question on the SNOT-22 (smell-SNOT).

RESULTS

159 patients with pre- and post-operative SNOT-22 scores were included. Average total SNOT-22 scores worsened from pre-operative (16.91 ± 16.91) to POM1 (25.15 ± 20.83, P < .001), with no difference from pre-operative (16.40 ± 15.88) to POM6 (16.27 ± 17.92, P = .936) or pre-operative (13.63 ± 13.54) to POM12 (12.60 ± 16.45, P = .651). Average smell-SNOT scores worsened from pre-operative (0.40 ± 1.27) to POM1 (2.09 ± 2.01, P < .001), and pre-operative (0.46 ± 1.29) to POM6 (1.13 ± 2.45, P = .002), with no difference from pre-operative (0.40 ± 1.07) to POM12 (0.71 ± 1.32, P = .100). Female gender had a 0.9-point (95% CI 0.1 to 1.6) P = .021, increase in smell-SNOT at POM1, resolving by POM6 (0.1 [-0.9 to 1.1], P = .800) and POM12 (0.0 [-1.0 to 0.9], P = .942). Septoplasty with tunnel approach had a 1.1 [0.2 to 2.0] out of 5-point (P = .023) increase in smell-SNOT at POM1, resolving by POM6 (0.2 [-1.1 to 1.6], P = .764) and POM12 (0.4 [-0.9 to 1.6], P = .567). Female gender had a 9.5 (4.0 to 15.1)-point (P = .001) increase in SNOT-22 scores at POM1, resolving by POM6 (3.4 [-3.0 to 9.8], P = .292) and POM12 (6.4 [-5.4 to 18.2], P = .276). Intra-operative CSF leak had an 8.6 [2.1 to 15.1]-point (P = .009) increase in SNOT-22 scores at POM1, resolving by POM6 (5.4 [-1.7 to 12.5], P = .135), and POM12 (1.1 [-12.9 to 15.1], P = .873).

CONCLUSION

Changes in subjective olfaction and sinonasal QOL after TSA may be associated with gender, operative approach, and intra-operative CSF leak, resolving 6-12 months post-operatively.

Food for Thought: Optical Sensor Arrays and Machine Learning for the Food and Beverage Industry

Arrays of cross-reactive sensors, combined with statistical or machine learning analysis of their multivariate outputs, have enabled the holistic analysis of complex samples in biomedicine, environmental science, and consumer products. Comparisons are frequently made to the mammalian nose or tongue and this perspective examines the role of sensing arrays in analyzing food and beverages for quality, veracity, and safety. I focus on optical sensor arrays as low-cost, easy-to-measure tools for use in the field, on the factory floor, or even by the consumer. Novel materials and approaches are highlighted and challenges in the research field are discussed, including sample processing/handling and access to significant sample sets to train and test arrays to tackle real issues in the industry. Finally, I examine whether the comparison of sensing arrays to noses and tongues is helpful in an industry defined by human taste.

Pronounced Olfactory Habituation with Age

OBJECTIVES

Olfactory habituation is a transient decrease in olfactory sensitivity caused by prolonged odor exposure, aiding in the discernment of new olfactory stimuli against the background. We explored the impact of subclinical olfactory impairment on odor habituation using age as a proxy.

METHODS

Before the actual experiment, the individual olfactory threshold for the rose-like odorant phenylethyl alcohol (PEA) was assessed separately for the left and right nostril using the "Sniffin' Sticks" test, and ratings for odor intensity and pleasantness were collected. After applying a nasal clip continuously delivering PEA odor to one nostril for 10 min and 2 h, respectively, threshold, intensity, and pleasantness were reassessed immediately after clip removal.

RESULTS

In the group of 80 participants (younger adults-mean age 27.7 ± 4.5 years; older adults-mean age 61.5 ± 4.7 years), olfactory thresholds were already significantly elevated after just 10 min, and this habituation was even more pronounced after 2 h. This effect could be observed bilaterally even though significantly more distinct on the exposed side. Older participants generally exhibited a more pronounced habituation on the exposed side after 2 h compared to the younger participants.

CONCLUSION

The results indicate that older people experience more notable habituation after extended exposure to odors. This is most likely due to the compromised olfactory function in age. Although older and younger subjects scored in the normosmic range when tested with standardized olfactory tests, the stress on the system after exposure to an odor clearly revealed the lower functionality of the aging sense of smell.

LEVEL OF EVIDENCE

3 Laryngoscope, 2024.

Comparison of Patient Characteristics and Olfactory Sensitivity for Trigger Odorants in Parosmia and Phantosmia

OBJECTIVES

This study aimed to determine the characteristics of patients with qualitative olfactory dysfunction (qualOD) and whether individuals with parosmia exhibit increased olfactory sensitivity to previously reported odorous triggers of parosmia.

METHODS

This study included individuals aged ≥18 years, divided into quantitative OD only, parosmia, and phantosmia groups. Data collected included: clinical-demographic data, "Sniffin' Sticks" scores, questionnaires (depression scale, importance of olfaction), and information about parosmia and phantosmia. A proportion of patients underwent trigger odor threshold testing for 2-Furfurylthiol [FFT] found in coffee and 2,6-nonadienal [Nonadienal] found in cucumber.

RESULTS

Those with parosmia were typically younger women, with shorter OD duration due to post-viral OD (PVOD), hyposmic/normosmic, and experienced parosmia more severely. Parosmia was 3.5 times more likely in PVOD. Those with phantosmia were older, with longer OD duration due to idiopathic OD, hyposmic/anosmic, and experienced phantosmia less severely. There were no significant differences between FFT and Nonadienal threshold scores in patients with parosmia, phantosmia, or only quantitative OD, but all groups had significantly increased olfactory sensitivity for trigger odors compared to phenyl ethyl alcohol (PEA).

CONCLUSION

Parosmia and phantosmia patients have distinct characteristics. This may provide clinicians with a better understanding of possible olfactory outcomes in these patients. The higher olfactory sensitivity of all groups to trigger odors compared to PEA raises interesting points about parosmia triggers and odors in the context of warning for danger, in relation to the pathophysiology of parosmia that may be worth exploring in future studies.

LEVEL OF EVIDENCE

3 Laryngoscope, 2024.

Determining Ultra-Low Organic Molecular Odor Thresholds in Air Helps Identify the Most Potent Fungal Aroma Compound

The determination of odor threshold values can be performed in various matrices, including air, and serves as a parameter to compare the potencies of odorous compounds. Typically, the odor thresholds in air are determined by gas chromatography-olfactory (GC-O) and referenced to an internal standard, most often (E)-dec-2-enal. Herein, a direct gas chromatography-flame ionization detector-olfactory analysis method for the determination of odor thresholds in air is reported. As model substrates for this novel approach, naturally occurring substances (R)-1-p-menthene-8-thiol as well as (3S,3aS,6R,7aS)-3,6-dimethyl-3a,4,5,6,7,7a-hexahydro-3H-1-benzofuran-2-one were used. The latter compound was synthesized from (-)-isopulegol and exhibited an extremely low odor recognition threshold of 1.9 × 10-6 ng L-1 air, the lowest value reported for a fungal aroma compound thus far.

Impact of Dupilumab on Sinonasal Symptoms and Outcomes in Severe Chronic Rhinosinusitis With Nasal Polyps

OBJECTIVES

To assess the severity of the top 5 22-item Sino-Nasal Outcome Test (SNOT-22) items ranked most important by patients with chronic rhinosinusitis with nasal polyps (CRSwNP), the effect of dupilumab on these items, and their association with objective disease measures.

STUDY DESIGN

Post hoc analysis of the SINUS-24 (NCT02912468) and SINUS-52 (NCT02898454) clinical trials.

SETTING

Multinational, multicenter, randomized, double-blind, placebo-controlled, parallel-group studies.

METHODS

Patients ranked the SNOT-22 items most affecting their health at baseline. Item symptom severity (0-5 scale) was assessed at baseline, Week 24 (W24), and Week 52 (W52). Changes in nasal polyps score (NPS) and Lund-Mackay (LMK) scores were assessed in patients with/without SNOT-22 items improvements of at least 1 severity group point at W24 and W52.

RESULTS

The SNOT-22 items ranked most important at baseline were "decreased sense of smell/taste" (87% of patients), followed by "nasal blockage" (82%), "postnasal discharge" (40%), "thick nasal discharge" (37%), and "wake up at night" (26%); 82%, 61%, 32%, 40%, and 26% of patients reported severe symptoms (score 4 or 5) for these items, respectively. Dupilumab improved score severity for all top 5 items versus placebo at W24 and W52. Improvements in NPS and LMK scores were numerically greater in patients with improvements in the SNOT-22 top 5 items.

CONCLUSION

Loss of smell/taste was ranked as the most important symptom by patients with CRSwNP. Dupilumab reduced the severity of the top 5 most important SNOT-22 items versus placebo, in parallel with improvements in objective disease measures.

CLINICAL TRIAL REGISTRATION

SINUS-24 and SINUS-52 clinical trials were registered with ClinicalTrials.gov, identifiers NCT02912468 and NCT02898454, respectively.

Olfactory Dysfunction in Adults from Rio Grande do Norte: A Cross-Sectional Study

Introduction  Smell is one of the senses of the human body, and it can be affected by several factors, such as viral infections, traumatic brain injury, iatrogenesis, smoking, and neurodegenerative and systemic diseases. Objectives  The main goal of the present study is to describe the epidemiology of olfactory disorders in Rio Grande do Norte (RN). More specifically, to determine the prevalence of olfactory dysfunction and to identify the main risk factors related to these dysfunctions in the state's population. Methods  A total of 180 volunteers living in the RN underwent the Connecticut Clinical Research Center (CCCRC) smell test and a clinical and demographic questionnaire. Results  A total of 58.89% of the patients presented normosmia and 87.78% were classified as having between normal and mild hyposmia. A statistically significant relationship was found between worse performance in the test and nasal surgery ( p  = 0.041) and the subjective feeling of not having an accurate sense of smell ( p  = 0.006 on the right nostril). There was no statistical relationship between the olfactory status and the report of coronavirus disease 2019 (COVID-19) infection ( p  = 0.254). Conclusion  The occurrence of altered sense of smell in our study was different from that reported in other studies that used the same test. The relationship with COVID-19 was not clear.

Differential involvement of the senses in disgust memories

One prediction derived from the disease avoidance account of disgust is that proximal disgust cues (smells, tastes and touches) should elicit this emotion more intensely than distal disgust cues (sights and sounds). If correct, then memories of disgusting experiences should involve smelling, tasting or touching to a greater degree than seeing or hearing. Two surveys were conducted on university students to test this idea, drawing upon their naturalistic experiences. Survey 1 (N = 127) asked participants to detail their most memorable disgusting, fear-provoking, morally repulsive and yucky/gross experience, with each recollection self-rated for sensory involvement. Survey 2 (N = 89) employed the same task, but this time, participants recollected their most common disgusting, fear-provoking, morally repulsive and yucky/gross experience in the preceding week. The majority of disgusting experiences were core disgusts-i.e. related to disease/pathogen presence or stimuli. The proximal and distal sensory cues contributed equally to individuals' most memorable core disgust experiences, but the proximal senses were more involved than the distal senses in individuals' most common core disgust experiences. Further, the proximal sensory cues, as compared with the distal sensory cues, were signficantly more involved in core disgust experiences than in morally repulsive and fear-provoking experiences. The implications of these findings for a disease avoidance account of disgust, for multi-sensory disgust research, and core disgust's classification as an emotion or a drive, are discussed.

Underestimated olfactory domains in Huntington's disease: odour discrimination and threshold

BACKGROUND

Olfaction has recently found clinical value in prediction, discrimination and prognosis of some neurodegenerative disorders. However, data originating from standard tests on olfactory dysfunction in Huntington's disease are limited to odour identification, which is only one domain of olfactory perceptual space.

METHOD

Twenty-five patients and 25 age- and gender-matched controls were evaluated by the Sniffin' Sticks test in three domains of odour threshold, odour discrimination, odour identification and the sum score of them. Patients' motor function was assessed based on the Unified Huntington's Disease Rating Scale.

RESULTS

Compared with controls, patients' scores of all olfactory domains and their sum were significantly lower. Besides, our patients' odour threshold and odour discrimination impairments were more frequently impaired than odour identification impairment (86 per cent and 81 per cent vs 34 per cent, respectively).

CONCLUSION

Olfactory impairment is a common finding in patients with Huntington's disease; it is not limited to odour identification but is more pronounced in odour discrimination and odour threshold.

Brain waves spectral analysis of human responses to odorous and non-odorous substances: a preliminary study

OBJECTIVE

The aim of this study was to identify the potential electrophysiological biomarkers of human responses by comparing the electroencephalogram brain wave changes towards lavender versus normal saline in a healthy human population.

METHOD

This study included a total of 44 participants without subjective olfactory disturbances. Lavender and normal saline were used as the olfactory stimulant and control. Electroencephalogram was recorded and power spectra were analysed by the spectral analysis for each alpha, beta, delta, theta and gamma bandwidth frequency upon exposure to lavender and normal saline independently.

RESULTS

The oscillatory brain activities in response to the olfactory stimulant indicated that the lavender smell decreased the beta activity in the left frontal (F7 electrode) and central region (C3 electrode) with a reduction in the gamma activity in the right parietal region (P4 electrode) (p < 0.05).

CONCLUSION

Olfactory stimulants result in changes of electrical brain activities in different brain regions, as evidenced by the topographical brain map and spectra analysis of each brain wave.

Sinonasal Outcomes of the Combined Transseptal/Transnasal Approach with Unilateral Nasoseptal Rescue Flap in Endoscopic Endonasal Transsphenoidal Surgery: A Propensity Score Matching Analysis

Objectives  The authors applied surgical techniques acquired during the use of endoscopic combined transseptal/transnasal approach to reduce approach-related morbidity and improve sinonasal outcomes. Study Design  This is a retrospective cohort study of a prospectively collected database. Setting  The study setting involves a tertiary referral center. Participants  A total of 86 patients who underwent endoscopic endonasal transsphenoidal surgery for newly diagnosed pituitary adenomas from April 2018 to March 2021 were included. Patients treated via the combined transseptal/transnasal approach served as the study group ( n  = 18); those treated via the bilateral transnasal approach comprised the control group ( n  = 68). From the control group, propensity score matching (PSM) analysis was further performed to account for potential confounders and selection bias. Main Outcome Measures  Paired analysis was performed for pre- and 6-month-postoperative time points in study group, control group, and PSM control group. Olfactory function was evaluated by Connecticut Chemosensory Clinical Research Center (CCCRC) test, Cross-Cultural Smell Identification Test (CCSIT), and sinonasal outcomes were assessed by Sino-Nasal Outcome Test-22 (SNOT-22). Results  In the study group, CCCRC ( p  = 0.517) and CCSIT ( p  = 0.497) did not show any significant difference before and after surgery. There was some improvement in the symptom score of SNOT-22, but it was not statistically significant ( p  = 0.115). In the control group adjusted with PSM, a significant decrease in olfaction ( p  = 0.047) was observed using CCCRC. The CCSIT score was also decreased but not significant ( p  = 0.163). Also, there was no difference in the improvement of SNOT-22 ( p  = 0.781). Conclusion  Our new surgical method preserves olfactory function without compromising surgical outcomes.

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

BACKGROUND

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.

OBJECTIVES

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.

MATERIAL AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

COVID-19: Post-vaccine Smell and Taste Disorders: Report of 6 Cases

Post-vaccine olfactory and gustatory disorders are very rare and were reported in patients who received influenza vaccines. In this article, we report 6 cases of post-coronavirus disease 2019 (COVID-19) vaccine olfactory and gustatory disorders in patients with negative nasal swabs. Precisely, olfactory and gustatory dysfunctions were reported in 5 and 1 patients, respectively. Sense disorders occurred after the first injection of AstraZeneca (n = 4) or the second injection of Pfizer (n = 2) vaccines. In 4 cases, the olfactory or gustatory disorder was confirmed with psychophysical evaluations. The duration of chemosensory dysfunction ranged from 4 to 42 days. None of the patient reported mid- or long-term olfactory or gustatory disorder. The occurrence of olfactory and gustatory dysfunctions in adults benefiting from COVID-19 vaccines is still rare but has to be known by otolaryngologists.

Functional magnetic resonance imaging in coronavirus disease 2019 induced olfactory dysfunction

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Validity and Reliability of the French Short Version of the Questionnaire of Olfactory Disorders-Negative Statements (sQOD-NS)

OBJECTIVE

To develop a French Short Version of the Questionnaire of Olfactory Disorders-Negative Statements (Fr-sQOD) to assess the quality of life impairments of patients with olfactory dysfunction (OD).

METHODS

Patients with OD and controls were enrolled from 2 academic centers. Individuals completed the Fr-sQOD, an OD visual analog scale severity, and the French version of the sinonasal outcome tool-22 (SNOT-22). Cronbach α was used to measure the internal consistency of Fr-sQOD. The reliability and the external validity of Fr-sQOD were assessed through a test-retest approach and by correlating Fr-sQOD with SNOT-22 scores, respectively. The external validity was assessed by correlation analysis between Fr-sQOD and the result of an assessment of the severity of OD on a visual analog scale.

RESULTS

Eighty patients completed the evaluations. The internal consistency was adequate (Cronbach α .96), and the test-retest reliability was high in the entire cohort (rs = 0.877, P < .001). The correlation between Fr-sQOD total scores and the severity of OD was moderate but significant (rs = -0.431; P = .001) supporting an acceptable external validity. Patients with OD had a significantly higher score of Fr-sQOD than healthy individuals (P < .001), indicating a high internal validity.

CONCLUSION

The Fr-sQOD is a reliable and valid self-administered tool in the evaluation of the impact of OD on quality of life of French-speaking patients.

Poor olfaction prior to cardiac surgery: Association with cognition, plasma neurofilament light, and post-operative delirium

OBJECTIVES

Post-operative delirium (POD) affects up to 50% of cardiac surgery patients, with higher incidence in older adults. There is increasing need for screening tools that identify individuals most vulnerable to POD. Here, we examined the relationship between pre-operative olfaction and both incident POD and POD severity in patients undergoing cardiac surgery. We also examined cross-sectional relationships between baseline olfaction, cognition, and plasma neurofilament light (NfL).

METHODS

Individuals undergoing cardiac surgery (n = 189; mean age = 70 years; 75% men) were enrolled in a clinical trial of cerebral autoregulation monitoring. At baseline, odor identification performance (Brief Smell Identification Test), cognitive performance, and plasma concentrations of NfL levels (Simoa™ NF-Light Assay) were measured. Delirium was assessed with the Confusion Assessment Method (CAM) or CAM-ICU, and delirium severity was assessed using the Delirium Rating Scale-Revised-98. The association of baseline olfaction, delirium incidence, and delirium severity was examined in regression models adjusting for age, duration of cardiopulmonary bypass, logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE), and baseline cognition.

RESULTS

Olfactory dysfunction was present in 30% of patients, and POD incidence was 44%. Pre-operative olfactory dysfunction was associated with both incident POD (OR = 3.17, p = 0.001) and greater severity of POD after cardiac surgery (OR = 3.94 p < 0.001) in models adjusted for age, duration of bypass, and a surgical risk score. The addition of baseline cognition attenuated the strength of the association, but it remained significant for incident POD (OR = 2.25, p = 0.04) and POD severity (OR 2.10, p = 0.04). Poor baseline olfaction was associated with greater baseline cognitive dysfunction (p < 0.001) and increased baseline plasma NfL concentrations (p = 0.04). Neither age, cognition, nor baseline NFL concentration modified the association of impaired olfaction and delirium outcomes.

CONCLUSIONS

Olfactory assessment may be a useful pre-surgical screening tool for the identification of patients undergoing cardiac surgery at increased risk of POD. Identifying those at highest risk for severe delirium and poor cognitive outcomes following surgery would allow for earlier intervention and pre-operative rehabilitation strategies, which could ultimately impact the functional disability and morbidity associated with POD.

Treatment of Postinfectious Olfactory Dysfunction Using Corticosteroids

OBJECTIVE

This study aimed to analyze the efficacy of different doses and forms of corticosteroids in the treatment of postinfectious olfactory dysfunction and to specify the factors related to the curative effects.

METHODS

The medical records of patients diagnosed with postinfectious olfactory dysfunction from January 2018 to May 2019 were reviewed. All patients received different doses of oral corticosteroids for 12 days or inhaled corticosteroids for 1 month.

RESULTS

A review of the records of 43 patients showed that the mean follow-up time was 6.66 months, and the overall effective rate of treatment was 48.8%. Postinfectious olfactory dysfunction exhibited distinct seasonality, with the highest incidence in March. The curative effect was significantly related to the olfactory discrimination threshold at the first consultation (P = .022), but not significantly associated with age (P = .325), sex (P = .924), duration of disease (P = .526), follow-up time (P = .489), or treatment program (P = .330).

CONCLUSIONS

Different doses and forms of corticosteroids showed no significant difference in the therapeutic effect on postinfectious olfactory dysfunction. The olfactory discrimination threshold at the first consultation was the most important factor influencing the prognosis.

Clinical utility of and correlation between Sniffin' Sticks and TIB smell identification test (TIBSIT) among Hong Kong Chinese with or without chronic rhinosinusitis

Introduction

Olfactory dysfunction (OD) is common among patients with chronic rhinosinusitis (CRS). Validated and culturally specific tests, such as the "Sniffin' Sticks" test (SST) and the TIB Smell Identification Test (TIBSIT), are crucial for the diagnosis and monitoring of OD. However, they have not been utilised in Hong Kong Chinese and their correlations are unknown.

Methods

Twelve CRS patients and twenty healthy volunteers were prospectively recruited from a joint allergy-otorhinolaryngology clinic in Hong Kong and performed both SST and TIBSIT. Demographics, baseline characteristics and all test results were compared and analysed.

Results

Patients with CRS demonstrated significantly lower test scores than healthy controls (all p < 0.001). Significant and strong correlations were observed between all composite and subtest scores, particularly between the composite SST and TIBSIT scores (ρ = 0.789, p < 0.001). Multivariate analysis demonstrated that the presence of CRS and increasing age were significantly associated with OD.

Conclusion

Both SST and TIBSIT are useful olfactory tests and are strongly correlated among Hong Kong Chinese. We advocate that either test can be used for measuring OD among CRS patients.

An electronic nose can identify humans by the smell of their ear

Terrestrial mammals identify conspecifics by body odor. Dogs can also identify humans by body odor, and in some instances, humans can identify other humans by body odor as well. Despite the potential for a powerful biometric tool, smell has not been systematically used for this purpose. A question arising in the application of smell to biometrics is which bodily odor source should we measure. Breath is an obvious candidate, but the associated humidity can challenge many sensing devices. The armpit is also a candidate source, but it is often doused in cosmetics. Here, we test the hypothesis that the ear may provide an effective source for odor-based biometrics. The inside of the ear has relatively constant humidity, cosmetics are not typically applied inside the ear, and critically, ears contain cerumen, a potent source of volatiles. We used an electronic nose to identify 12 individuals within and across days, using samples from the armpit, lower back, and ear. In an identification setting where chance was 8.33% (1 of 12), we found that we could identify a person by the smell of their ear within a day at up to ~87% accuracy (~10 of 12, binomial P < 10-5), and across days at up to ~22% accuracy (~3 of 12, binomial P < 0.012). We conclude that humans can indeed be identified from the smell of their ear, but the results did not imply a consistent advantage over other bodily odor sources.

Factors influencing olfactory function in an adult general population sample: the CHRIS study

The sense of smell allows for the assessment of the chemical composition of volatiles in our environment. Different factors are associated with reduced olfactory function, including age, sex, as well as health and lifestyle conditions. However, most studies that aimed at identifying the variables that drive olfactory function in the population suffered from methodological weaknesses in study designs and participant selection, such as the inclusion of convenience sample or only of certain age groups, or recruitment biases. We aimed to overcome these issues by investigating the Cooperative Health Research in South Tyrol (CHRIS) cohort, a population-based cohort, by using a validated odor identification test. Specifically, we hypothesized that a series of medical, demographic and lifestyle variables is associated with odor identification abilities. In addition, our goal was to provide clinicians and researchers with normative values for the Sniffin' Sticks identification set, after exclusion of individuals with impaired nasal patency. We included 6,944 participants without acute nasal obstruction and assessed several biological, social, and medical parameters. A basic model determined that age, sex, years of education, and smoking status together explained roughly 13% of the total variance in the data. We further observed that variables related to medical (positive screening for cognitive impairment and for Parkinson's disease, history of skull fracture, stage 2 hypertension) and lifestyle (alcohol abstinence) conditions had a negative effect on odor identification scores. Finally, we provide clinicians with normative values for both versions of the Sniffin' Sticks odor identification test, i.e. with 16 items and with 12 items.

What are olfaction and gustation, and do all animals have them?

Different animals have distinctive anatomical and physiological properties to their chemical senses that enhance detection and discrimination of relevant chemical cues. Humans and other vertebrates are recognized as having 2 main chemical senses, olfaction and gustation, distinguished from each other by their evolutionarily conserved neuroanatomical organization. This distinction between olfaction and gustation in vertebrates is not based on the medium in which they live because the most ancestral and numerous vertebrates, the fishes, live in an aquatic habitat and thus both olfaction and gustation occur in water and both can be of high sensitivity. The terms olfaction and gustation have also often been applied to the invertebrates, though not based on homology. Consequently, any similarities between olfaction and gustation in the vertebrates and invertebrates have resulted from convergent adaptations or shared constraints during evolution. The untidiness of assigning olfaction and gustation to invertebrates has led some to recommend abandoning the use of these terms and instead unifying them and others into a single category-chemical sense. In our essay, we compare the nature of the chemical senses of diverse animal types and consider their designation as olfaction, oral gustation, extra-oral gustation, or simply chemoreception. Properties that we have found useful in categorizing chemical senses of vertebrates and invertebrates include the nature of peripheral sensory cells, organization of the neuropil in the processing centers, molecular receptor specificity, and function.

Cross-cultural modification of the University of Pennsylvania smell identification test for the Saudi Arabian population: Validation and normative values

OBJECTIVES

To develop a reliable version of the Saudi Arabian-University of Pennsylvania smell identification test (SA-UPSIT) and to establish normative values for both genders.

METHODS

This cross-sectional study was carried out on voluntarily recruited normal participants in King Saud University Medical City, Riyadh, Saudi Arabia, from April 2018 to May 2023. Culture-familiar odors were chosen and the kit was translated into Arabic for the study. The test was modified 3 times in 4 versions. Following this, a random sample was collected to carry out a re-test after 6 weeks.

RESULTS

A total of 288 subjects participated in the development of the SA-UPSIT across all versions, including 146 females and 142 males. The average age of the participants was 28.4±9.9 years. In the final version, 111 participants scored an average of 34.5±2.5 for the total score, 35±2.3 for females, and 34.1±2.6 for males. The test-retest reliability coefficient was 0.73, indicating acceptable reliability.

CONCLUSION

The new changes carried out to the SA-UPSIT increased the average scores and demonstrated good reliability, making it clinically applicable for diagnosing and monitoring olfactory dysfunction.

Morphology of nares associated with stereo-olfaction in baleen whales

The sensory mechanisms used by baleen whales (Mysticeti) for locating ephemeral, dense prey patches in vast marine habitats are poorly understood. Baleen whales have a functional olfactory system with paired rather than single blowholes (nares), potentially enabling stereo-olfaction. Dimethyl sulfide (DMS) is an odorous gas emitted by phytoplankton in response to grazing by zooplankton. Some seabirds use DMS to locate prey, but this ability has not been demonstrated in whales. For 14 extant species of baleen whale, nares morphometrics (imagery from unoccupied aerial systems, UAS) was related to published trophic level indices using Bayesian phylogenetic mixed modelling. A significant negative relationship was found between nares width and whale trophic level (β = -0.08, lower 95% CI = -0.13, upper 95% CI = -0.03), corresponding with a 39% increase in nares width from highest to lowest trophic level. Thus, species with nasal morphology best suited to stereo-olfaction are more zooplanktivorous. These findings provide evidence that some baleen whale species may be able to localize odorants e.g. DMS. Our results help direct future behavioural trials of olfaction in baleen whales, by highlighting the most appropriate species to study. This is a research priority, given the potential for DMS-mediated plastic ingestion by whales.

Effectiveness of Platelet-Rich Plasma for COVID-19-Related Olfactory Dysfunction: A Controlled Study

OBJECTIVE

To investigate the effectiveness of platelet-rich plasma (PRP) injection into the olfactory clefts of coronavirus disease 2019 (COVID-19) patients with persistent olfactory dysfunction (OD).

STUDY DESIGN

Controlled study.

SETTING

Multicenter study.

METHODS

From March 2022 to November 2022, COVID-19 patients with persistent OD were recruited from three European hospitals to undergo PRP injections into the olfactory clefts. Olfactory function was evaluated at baseline and 10 weeks postinjection with the Olfactory Disorder Questionnaire (ODQ) and threshold, discrimination, and identification (TDI) test. Data were compared with a control group of untreated patients.

RESULTS

Eighty-one patients who underwent PRP injection and 78 controls were included. Sixty-five PRP patients (80.3%) experienced subjective smell improvement after a mean duration of 3.4 ± 1.9 weeks. The parosmia, life quality statement, and ODQ sub- and total scores significantly decreased from pre- to 10-week postinjection in the PRP group. The TDI sub- and total scores significantly increased 10 weeks postinjection. In controls, the ODQ score did not change over time, while the discrimination, identification, and total TDI scores significantly increase after 10 weeks of follow-up. The 10-week TDI and ODQ scores were significantly better in the PRP group compared with the controls.

CONCLUSION

Patients who underwent PRP injection reported better 10-week subjective and objective smell outcomes than controls. Future randomized-controlled studies using saline injection into the olfactory cleft of controls are needed to determine the superiority of PRP over placebo.

The Role of the Olfactory System in Obesity and Metabolism in Humans: A Systematic Review and Meta-Analysis

Obesity, linked to chronic diseases, poses a global health challenge. While the role of the olfactory system in energy homeostasis is well-documented in rodents, its role in metabolism regulation and obesity in humans remains understudied. This review examines the interplay between olfactory function and metabolic alterations in human obesity and the effects of bariatric surgery on olfactory capabilities in humans. Adhering to PRISMA guidelines, a systematic review and meta-analysis was conducted, focusing exclusively on original human studies. From 51 articles, 14 were selected for the meta-analysis. It was found that variations in olfactory receptor genes influence the susceptibility to odors and predisposition to weight gain and poor eating habits. Bariatric surgery, particularly sleeve gastrectomy, shows significant improvements in olfactory function (SMD 2.37, 95% CI [0.96, 3.77], I = 92%, p = 0.001), especially regarding the olfactory threshold (SMD -1.65, 95% CI [-3.03, -0.27], I = 81%, p = 0.02). There is a bidirectional relationship between olfactory function and metabolism in humans. Bariatric surgery improves olfactory perception in obese patients, but it is still unclear if impacting the olfactory system directly affects eating behavior and the energy balance. However, these findings open novel avenues for future studies addressing the olfactory system as a novel target to alter systemic metabolism in humans.

Olfactory recovery following omicron variant infection: a psychophysical prospective case-control study with six-month follow up

OBJECTIVE

This study aimed to evaluate the recovery of olfactory function at six months in individuals infected with the coronavirus disease 2019 omicron variant, using psychophysical tests.

METHODS

A prospective case-control study that included severe acute respiratory syndrome coronavirus-2 patients infected in February and March 2022 was conducted. Patients underwent the Sniffin' Sticks test within 10 days of infection and again after at least 6 months. The olfactory scores were compared with those of a control group.

RESULTS

In all, 102 patients and 120 controls were enrolled in the study. At baseline, 26 patients (25.5 per cent) self-reported smell loss. The median threshold, discrimination and identification score was 33.6 (interquartile range, 12.5) for the cases and 36.5 (interquartile range, 4.38) for the controls (p < 0.001). Based on the threshold, discrimination and identification scores, 12 controls and 34 patients reported olfactory dysfunction (p < 0.001). Eighty cases underwent re-evaluation at six months; the median threshold, discrimination and identification score was 37.1 (interquartile range, 4.75) with no significant differences compared with the controls.

CONCLUSION

Six months after infection, the prevalence of olfactory dysfunction in patients did not differ significantly from the control population.

Validity and Reliability of the Malay Questionnaire for Olfactory Disorders

Background

Olfactory disorders (OD) are an umbrella term for a diverse group of smell problems. Numerous tests and questionnaires have been formulated to identify and test the severity of smell impairment, which is not readily available or translated for the Malaysian population. This study aimed to translate the Questionnaire for Olfactory Disorders (QOD) and validate and test the reliability of the Malay Questionnaire for Olfactory Disorders (mQOD).

Methods

This cross-sectional study was conducted in two tertiary centres. A forward and backward translation was conducted for the QOD. The translated questionnaire was distributed to subjects with self-reported smell disorders on days 1 and 7. Internal consistency was analysed using Cronbach's alpha and test-retest reliability was tested with an intraclass correlation coefficient. Confirmatory factor analysis was performed to test construct validity.

Results

A total of 375 participants were recruited, 52 dropped out and 323 completed the questionnaire a second time. The Cronbach's alpha coefficient was 0.537 for parosmia (P), 0.892 for life quality (LQ), 0.637 for sincerity (S) and 0.865 for visual analogue score (VAS). The intraclass correlation coefficient (ICC) for domain scores was > 0.9, while the ICC for all items was good to excellent. A three-factor model for mQOD showed an acceptable fit with indices chi-square value (CMIN)/degree of freedom (DF) = 3.332, Tucker-Lewis fit index (TLI) = 0.923, comparative fit index (CFI) = 0.939, root mean square error of approximation (RMSEA) = 0.079 and standardised root mean square residual (SRMR) = 0.0574.

Conclusion

The mQOD is a valid and reliable tool for assessing OD in patients.

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.

Olfactory and gustatory disorders associated with SARS-CoV-2 infection in children and adults: a topic review

This paper is aimed at comprehensively reviewing olfactory and gustatory disorders caused by SARS-CoV-2 in children and adults. An electronic and manual search was done on three databases: MEDLINE, Embase, and Web of Science. Inclusion criteria included publications written in English, involving humans in the age range of 0 to 99 years that were captured by a controlled vocabulary of thesaurus terms. Olfactory and gustatory disorders rates in COVID-19 ranged from 22% to 71.9% in adults and 16.6% to 25.8% in children. Olfactory and gustatory disorders might appear as the first symptom, and in adults might even be the only symptom (4.8% to 10%). Anosmia is the most common olfactory disorder and hypogeusia is the most common gustatory disorder. In 33% to 89% of cases, olfactory and gustatory disorders resolve spontaneously within a few weeks, coinciding with the resolution of other COVID-19 symptoms, both in adults and children. However, in some patients, olfactory and gustatory disorders persist beyond the resolution of other symptoms. Notably, children generally experience a swifter and more favorable recovery compared to adults. The precise pathogenesis underlying olfactory and gustatory disorders in the context of COVID-19 remains unclear and is likely multifactorial. Presently, no established treatment protocol exists for olfactory and gustatory disorders and current treatments reviewed lack robust evidence and are not readily available for clinical use. Olfactory training represents the only therapy currently recommended by international authorities. Pediatric practitioners and general dental practitioners should be aware of olfactory and gustatory disorders in both pediatric and adult populations, including their biologic mechanisms, treatment options, and recovery rates.

Effect of Radiotherapy on Sino-nasal Function in Nasopharynx Cancer Patients

Introduction: Radiotherapy causes significant nasal comorbidity in nasopharynx cancer (NPC) patients. However, the literature addressing the sino-nasal quality of life (QoL) of those patients, especially on structural and functional changes after radiotherapy, is limited. Method: It is a case-control study with 14 NPC groups and 14 healthy control group. The sino-nasal QoL, including the olfactory threshold using Butanol Threshold Test (BTT), the olfactory identification level using the University of Pennsylvania Smell Identification Test (UPSIT), nasal symptoms using the sino-nasal outcome test (SNOT-22) questionnaire, nasal cross-sectional area, nasal flow, and nasal resistance using the acoustic rhinometry and rhinomanometry, were measured and compared. Result: The mean BTT score of the control group was higher than that of the NPC group (5.17 vs 2.71). The UPSIT score of the control group was higher than that of the NPC group (31.93 vs 25.14). The mean SNOT-22 score of control group was lower than that of the NPC group of (16.71 vs 37.71). All 3 results are statistically significant (P < .05). However, there is no statistical difference in nasal cross-sectional area, nasal flow, and nasal resistance between these 2 groups. Conclusion: In this study, we concluded that NPC patients who received radiotherapy suffered a worsening of sino-nasal functional changes, including the olfaction threshold, olfaction identification, and nasal symptoms. However, the sino-nasal structural changes on nasal cross-sectional area, nasal flow, and nasal resistance after radiation remain questionable.

Sodium valproate: cacosmia and dysgeusia as uncommon side effects

Smell and taste disturbances are potential adverse reactions of many drugs used in Psychiatry, such as antidepressants, anti-Parkinson agents, lithium, minor and major tranquilizers. To our knowledge, only one clinical case regarding valproate and cacosmia has been reported so far. However, several anticonvulsants are reported to cause taste and smell disturbances, although the underlying etiology is currently unclear. Our patient developed cacosmia and dysgeusia when taking valproic acid, both effects quickly disappeared upon drug discontinuation. In this article we not only report this uncommon side effect, but we discuss the plausible mechanisms behind such an adverse reaction. Our case is to date the second similar case in the literature. The aim of the present article is to make clinicians informed about this very uncommon and unpleasant side effect.

Adaptive olfactory circuitry restores function despite severe olfactory bulb degeneration

The olfactory bulb (OB) is a critical component of mammalian olfactory neuroanatomy. Beyond being the first and sole relay station for olfactory information to the rest of the brain, it also contains elaborate stereotypical circuitry that is considered essential for olfaction. Indeed, substantial lesions of the OB in rodents lead to anosmia. Here, we examined the circuitry that underlies olfaction in a mouse model with severe developmental degeneration of the OB. These mice could perform odor-guided tasks and even responded normally to innate olfactory cues. Despite the near total loss of the OB, piriform cortices in these mice responded to odors, and its neural activity sufficed to decode odor identity. We found that sensory neurons express the full repertoire of olfactory receptors, and their axons project primarily to the rudiments of the OB but also, ectopically, to olfactory cortical regions. Within the OB, the number of principal neurons was greatly reduced, and the morphology of their dendrites was abnormal, extending over large regions within the OB. Glomerular organization was totally lost in the severe cases of OB degeneration and altered in the more conserved OBs. This study shows that olfactory functionality can be preserved despite reduced and aberrant circuitry that is missing many of the elements believed to be essential for olfaction, and it may explain reported retention of olfaction in humans with degenerated OBs.

Coronavirus disease 2019 related parosmia: an exploratory survey of demographics and treatment strategies

OBJECTIVE

To investigate the clinical features, therapeutic efficacy and symptom time course of post-coronavirus disease 2019 parosmia.

METHODS

A 22-item online questionnaire was distributed to AbScent research group and Facebook coronavirus disease 2019 anosmia group adult members to assess clinical features, interventions and their subjective efficacy for parosmia.

RESULTS

A total of 209 participants (86 per cent females) reported: smell loss on average 3 days after coronavirus symptoms, recovery 4 weeks later, and first parosmia symptoms 12 weeks post infection. Respondents reported 10 per cent body weight loss, and listed onion and garlic as significant parosmia triggers. Regarding quality of life, depression was the most cited item (54 per cent). Smell training was trialled by 74 per cent of participants, followed by nasal corticosteroid spray (49 per cent). Stellate ganglion block, trialled by 16 per cent of respondents, had the highest reported improvement (45 per cent), with 21 per cent reporting a sustained benefit - the highest rate amongst registered treatment options.

CONCLUSION

Post-coronavirus parosmia has a significant impact and remains challenging to treat. Stellate ganglion block appears to be successful relative to other reported treatments. Further research into the pathophysiology, efficacy and mechanism of stellate ganglion block effect is warranted.

The PEA Bead Test as a Screening Tool for Olfactory Dysfunction: A Preliminary Study

This study, conducted in a single tertiary hospital, aimed to evaluate the 2-phenylethyl alcohol (PEA)-based sniffing bead test as a screening tool for olfactory dysfunction suitable for implementation in otorhinolaryngology and other settings, including general practice clinics. A total of 139 patients were enrolled, all of whom underwent both the PEA bead test and conventional psychophysical olfactory function testing. Characteristics such as age, sex, concurrent diseases, smoking history, and presence of gustatory dysfunction were reviewed. Statistical analyses included receiver operating characteristic curve analysis, area under the curve determination, and multivariate linear regression guided by the Akaike information criterion. Significant correlations were found between the PEA bead test and various subsets of the conventional YSK olfactory function test: threshold (r = 0.631), discrimination (r = 0.455), and identification (r = 0.596), as well as the composite threshold-discrimination-identification score (r = 0.686). These correlations remained significant even when adjusting for other clinical characteristics. The PEA bead test showed a sensitivity of 0.778 and a specificity of 0.958 for discriminating olfactory dysfunction at a cutoff value of ≥1. These findings indicate that the PEA bead test could be a valuable screening tool for olfactory dysfunction across diverse clinical settings. Further large-scale, multicenter research is recommended to confirm these preliminary results.

Olfactory Stimulation as Environmental Enrichment for Domestic Horses-A Review

Horses constantly face several challenges inherent to the domestic environment, and it is common for the expression of their natural behavior to be drastically limited. Environmental enrichment has been suggested as an alternative to improve the captive situation of domestic horses. Among the recently proposed enrichment strategies, olfactory stimulation has emerged as a method for improving several aspects related to animal behavior. Olfaction is a sensory modality that plays a significant role in the expression of equine behavior, and in recent years, studies have shown that olfactory stimulation can influence the physiological and behavioral parameters of horses. This review provides current information on the anatomical particularities of the equine olfactory system, presents the physiological mechanisms involved in the odor detection process, and demonstrates how stress can interfere with this process. Finally, the use of olfactory stimulation as an environmental enrichment for domestic horses (Equus ferus caballus) is explored. The need for new studies that answer pertinent questions related to this topic is discussed throughout the manuscript.

Taste and smell alterations affect nutritional status in children under chemotherapy

AIM

This study aimed to evaluate the incidence of self-reported taste and smell alterations (TSA) in cancer paediatric patients and evaluate the impact of TSA on nutritional status in this population. We also developed and validated a composite score to detect TSA in children undergoing chemotherapy.

METHODS

Paediatric patients who were undergoing chemotherapy in a paediatric oncology unit were included. TSA were assessed from the Gustonco questionnaire from which a composite score was developed and internally validated, eating behaviour was assessed using Child Eating Behaviour Questionnaire, and major weight loss was defined from nutritional status. All data were calculated at 1, 3 and 6 months after chemotherapy start. Associations between nutritional status and scores were studied by using logistic models.

RESULTS

Among 49 patients included, TSA occurred in 71.7% of patients at 1 month after chemotherapy start and persisted at 3 and 6 months. TSA led to altered appetite since 1 month after chemotherapy start. The occurrence of a major weight loss at 6 months seemed to be associated with a high Gustonco score.

CONCLUSION

Taste and smell alterations often occurred in paediatric cancer patients after chemotherapy start and seemed to be associated with impaired nutrition at 6 months after chemotherapy.

Chemosensory Dysfunction 3-Months After COVID-19, Medications and Factors Associated with Complete Recovery

OBJECTIVES

To examine the longitudinal prevalence and recovery of olfactory, gustatory, and oral chemesthetic deficits in a sizable cohort of SARS-CoV-2 infected persons using quantitative testing. To determine whether demographic and clinical factors, mainly the medications used after the COVID-19 diagnosis, influence the test measures.

METHODS

Prospective cohort in a hospital with primary, secondary, tertiary, and quaternary care. Patients with confirmed COVID-19 were tested during the acute infection phase (within 15 days of initial symptom, n = 187) and one (n = 113) and 3 months later (n = 73). The University of Pennsylvania Smell Identification Test, the Global Gustatory Test, and a novel test for chemesthesis were administered at all visits.

RESULTS

During the acute phase, 93% were anosmic or microsmic and 29.4% were hypogeusic. No one was ageusic. A deficit in oral chemesthesis was present in 13.4%. By 3 months, taste and chemesthesis had largely recovered, however, some degree of olfactory dysfunction remained in 54.8%. Remarkably, patients who had been treated with anticoagulants tended to have more olfactory improvement. Recovery was greater in men than in women, but was unrelated to disease severity, smoking behavior, or the use of various medications prior to, or during, COVID-19 infection.

CONCLUSIONS

When using quantitative testing, olfactory disturbances were found in nearly all SARS-CoV-2 infected patients during the acute infection phase. Taste or chemesthetic deficits were low. Olfactory impairment persisted to some degree in over half of the patients at the 3-month follow-up evaluation, being more common in women and less common in those who had been treated earlier with anticoagulants.

LEVEL OF EVIDENCE

3.

Impacts of sensory multimodality congruence and familiarity with short use on cosmetic product evaluation

Cross-modal association between sensory modalities is a natural phenomenon in the perception of our environment. For cosmetic evaluation, touch and smell are the two major sensory modalities involved in the whole product perception. In this study, we investigate whether a specific cosmetic texture is preferentially associated with a specific fragrance: congruence between texture and fragrance. In addition, we investigate whether 1-week use of a fragrance-texture congruent or non-congruent product can influence user's whole product appreciation and well-being. We have conducted a four-test experiment with 29 participants; first in the laboratory to evaluate: six fragrances and four textures individually with free description (test 1); the same stimuli with a description with cross-modal descriptors (test 2); 10 fragrance-texture combined products (test 3); and secondly at home, two fragrance-texture combined products: one congruent and one non-congruent (test 4). Results showed that: (1) For a given texture type, specific olfactory notes are necessary to lead to a congruent cross-modal pairing product. (2) Sensory modal congruent products produce the highest hedonic response. (3) Real-life use or familiarisation with a product can influence not only the degree of cross-modal congruence but also overall cosmetic product appreciation.

Dupilumab in the treatment of severe uncontrolled chronic rhinosinusitis with nasal polyps (CRSwNP): A multicentric observational Phase IV real-life study (DUPIREAL)

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is associated with significant morbidity and reduced health-related quality of life. Findings from clinical trials have demonstrated the effectiveness of dupilumab in CRSwNP, although real-world evidence is still limited.

METHODS

This Phase IV real-life, observational, multicenter study assessed the effectiveness and safety of dupilumab in patients with severe uncontrolled CRSwNP (n = 648) over the first year of treatment. We collected data at baseline and after 1, 3, 6, 9, and 12 months of follow-up. We focused on nasal polyps score (NPS), symptoms, and olfactory function. We stratified outcomes by comorbidities, previous surgery, and adherence to intranasal corticosteroids, and examined the success rates based on current guidelines, as well as potential predictors of response at each timepoint.

RESULTS

We observed a significant decrease in NPS from a median value of 6 (IQR 5-6) at baseline to 1.0 (IQR 0.0-2.0) at 12 months (p < .001), and a significant decrease in Sino-Nasal Outcomes Test-22 (SNOT-22) from a median score of 58 (IQR 49-70) at baseline to 11 (IQR 6-21; p < .001) at 12 months. Sniffin' Sticks scores showed a significant increase over 12 months (p < .001) compared to baseline. The results were unaffected by concomitant diseases, number of previous surgeries, and adherence to topical steroids, except for minor differences in rapidity of action. An excellent-moderate response was observed in 96.9% of patients at 12 months based on EPOS 2020 criteria.

CONCLUSIONS

Our findings from this large-scale real-life study support the effectiveness of dupilumab as an add-on therapy in patients with severe uncontrolled CRSwNP in reducing polyp size and improving the quality of life, severity of symptoms, nasal congestion, and smell.

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.

Disparity of smell tests in Alzheimer's disease and other neurodegenerative disorders: a systematic review and meta-analysis

Background

There are discrepancies of olfactory impairment between Alzheimer's disease (AD) and other neurodegenerative disorders. Olfactory deficits may be a potential marker for early and differential diagnosis of AD. We aimed to assess olfactory functions in patients with AD and other neurodegenerative disorders, to further evaluate the smell tests using subgroup analysis, and to explore moderating factors affecting olfactory performance.

Methods

Cross-sectional studies relating to olfactory assessment for both AD and other neurodegenerative disorders published before 27 July 2022 in English, were searched on PubMed, Embase and Cochrane. After literature screening and quality assessment, meta-analyses were conducted using stata14.0 software.

Results

Forty-two articles involving 12 smell tests that evaluated 2,569 AD patients were included. It was revealed that smell tests could distinguish AD from mild cognitive impairment (MCI), Lewy body disease (LBD), depression, and vascular dementia (VaD), but not from diseases such as frontotemporal dementia (FTD). Our finding indicated that in discriminating AD from MCI, the University of Pennsylvania Smell Identification Test (UPSIT) was most frequently used (95%CI: -1.12 to -0.89), while the Brief Smell Identification Test (B-SIT), was the most widely used method in AD vs. LBD group. Further subgroup analyses indicated that the methods of smell test used contributed to the heterogeneity in olfactory threshold and discrimination scores in group AD vs. MCI. While the moderating variables including age, MMSE scores, education years in AD vs. LBD, were account for heterogeneity across studies.

Conclusion

Our finding suggests smell tests have potential value in early differential diagnosis of AD. UPSIT and its simplified variant, B-SIT, are widely used methods in the analyses.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php? RecordID = 357970 (PROSPERO, registration number CRD42022357970).

Intranasal Insulin for the Treatment of Persistent Post-COVID-19 Olfactory Dysfunction

OBJECTIVE

To investigate if intranasal insulin could be a treatment option for those suffering from recalcitrant olfactory dysfunction due to COVID-19.

STUDY DESIGN

Prospective interventional cohort with a single group.

SETTING

Sixteen volunteers with anosmia, severe hyposmia, or moderate hyposmia for more than 60 days as sequelae of severe acute respiratory syndrome coronavirus 2 infections were selected for the study. All volunteers reported that standard therapies, such as corticosteroids, have failed to improve their olfactory function.

METHODS

Olfactory function was assessed by the Chemosensory Clinical Research Center test of olfaction (COT) before and after the intervention. Changes in qualitative, quantitative, and global COT scores were investigated. The insulin therapy session consisted of placing into each olfactory cleft 2 pieces of gelatin sponge soaked with neutral protamine Hagedorn (NPH) insulin, 40 IU on each side. The procedure was repeated twice a week for 1 month. Glycaemic blood level was measured before and after each session.

RESULTS

The qualitative COT score rose 1.53 points, p = .0001, 95% confidence interval (CI) (-2.12 to -0.94). The quantitative COT score increased by 2.00 points, p = .0002, 95% CI (-3.59 to -1.41). Global COT score had an improvement of 2.01 points, p = .00003, 95% CI (-2.7 to -1.3). Glycaemic blood level dropped on average 10.4 mg/dL, p < .00003, 95% CI (8.1-12.8).

CONCLUSION

Our results suggest that the administration of NPH insulin into the olfactory cleft yields a rapid improvement in the sense of smell of patients suffering from persistent post-COVID-19 olfactory dysfunction. Moreover, the procedure seems to be safe and tolerable.

[Asociación entre rinitis alérgica e hiposmia]

Objective

To determine the association between AR and the frequency of hyposmia.

Method

Cross-sectional, case-control, non-probabilistic census survey in subjects between 14 and 50 years of age. AR was identified by clinical symptoms and positive skin tests. Olfactory function was assessed with the Sniffin Sticks Screening Test. This research was approved by the Ethics and Research Committees of the ISSSTE Regional Hospital "Dr. Valentín Gómez Farías": ZAPOPAN ISSSTE/CEI/488/2020.

Result

A total of 147 patients were included, 62 with AR and 85 controls. The average age was 33 years (35 years in AR and 31 years in controls). As a measure of association, the prevalence ratio was calculated, estimating that those with AR have 2.2 times more risk of having hyposmia than controls. Likewise, between them there was a calculated discrepancy of 12.5509 (expected discrepancy 3.84), and a statistical significance of 0.00039 (p=0.00039).

Conclusion

AR represents a chronic systemic inflammatory process that leads to hyposmia. Its correlation has been reported from 23 to 48%.1 Likewise, it is important to consider the role that olfaction plays in recognizing and interacting with our environment, and consequently the impact on the quality of life of those who suffer from it. AR significantly increases the risk for suffering hyposmia.

The association of gustatory dysfunction, olfactory dysfunction, and cognition in older adults

BACKGROUND

The association of gustatory dysfunction (GD) with quality of life (QOL) and cognition in older adults is understudied. Our objective was to study the prevalence of GD in the community and explore impacts and associated factors.

METHODS

A prospective, multi-institutional, pre-corona virus disease (COVID) cohort of adults aged 50 years and older had smell and taste testing using "Sniffin' Sticks" (TDI) and "Taste Strips." The impact of GD on mood, QOL, and social interaction was assessed through visual analog scales. Subjects completed the Questionnaire of Olfactory Disorders, Patient Health Questionnaire 9, Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment, and the DeJong scale of loneliness.

RESULTS

A total of 48 patients, average age of 54.7 years, were enrolled. Thirty-two percent experienced GD on taste strips, and 62% experienced olfactory dysfunction (OD) on TDI. Almost 30% (29.5%) had both GD and OD. GD and OD correlated with worsened cognitive function on MMSE (r = 0.392 and 0.05, p = 0.018 and 0.003). Subjects with both GD and OD had worse MMSE than either alone (p = 0.003). Dry mouth and difficult chewing correlated with GD (r = -0.37 and -0.31, p = 0.10 and 0.37). Self-reported GD and OD were correlated (r = 0.46, p = 0.001), as were psychophysical GD and OD (r = 0.394, p = 0.008). GD did not correlate with other metrics.

CONCLUSION

Thirty-two percent of subjects experienced GD on psychophysical testing, yet most are unaware without impacts on daily life. However, GD correlates with worsened cognitive function. Taste testing may play a role in screening of neurocognitive decline, and multisensory dysfunction may indicate of worsened cognitive states.

A role for GnRH in olfaction and cognition: Implications for veterinary medicine

Pulsatile secretion of gonadotropin-releasing hormone (GnRH) is essential for the activation and maintenance of the function of the hypothalamic-pituitary-gonadal (HPG) axis, which controls the onset of puberty and fertility. Two provocative recent studies suggest that, in addition to control reproduction, the neurons in the brain that produce GnRH are also involved in the control postnatal brain maturation, odour discrimination and adult cognition. Long-acting GnRH antagonists and agonists are commonly used to control fertility and behaviour in veterinary medicine, primarily in males. This review puts into perspective the potential risks of these androgen deprivation therapies and immunization on olfactory and cognitive performances and well-aging in domestic animals, including pets. We will also discuss the results reporting beneficial effects of pharmacological interventions restoring physiological GnRH levels on olfactory and cognitive alterations in preclinical models of Alzheimer's disease, which shares many pathophysiological and behavioural hallmarks with canine cognitive dysfunction. These novel findings raise the intriguing possibility that pulsatile GnRH therapy holds therapeutic potential for the management of this behavioural syndrome affecting older dogs.

Camera-based visual feedback learning aid for recovering sense of smell and taste in COVID-19 survivors: a proof-of-concept study

Introduction

A significant proportion of people report persistent COVID-19-related anosmia, hyposmia or parosmia, often accompanied with ageusia, hypogeusia or dysgeusia. Here, we present a proof-of-concept study that assessed the feasibility and acceptability of a new Camera-Based Visual Feedback Learning Aid (CVFLA) and explored its potential to restore or improve persistent COVID-19-related smell and/or taste impairment.

Methods

Fifteen adult participants with persistent smell and/or taste impairment were randomly allocated to 7-, 14-, or 21-days baseline of symptom monitoring before receiving the intervention in up to 10 sessions (length and frequency determined by participant's preference and progress) using a specialised CVFLA apparatus (patent no. 10186160). Smell and taste were assessed pre- and post-intervention subjectively, and also objectively using the ODOFIN Taste Strips and Sniffin Sticks. Participant feedback about their experience of receiving CVFLA was obtained via a semi-structured interview conducted by someone not involved in delivering the intervention.

Results

The intervention was extremely well received, with no dropouts related to the intervention. There was also a significant improvement in smell and taste from pre- to post-CVFLA intervention (mean number of sessions = 7.46, SD = 2.55; total duration = 389.96 min, SD = 150.93) both in subjective and objective measures. All participants, except one, reported experiencing some improvement from the 2nd or 3rd session.

Discussion

This new CVFLA intervention shows promise in improving COVID-19 related impairment in smell and taste with a very high level of acceptability. Further studies with larger samples are required to confirm its potential in restoring, improving or correcting smell and/or taste impairment in relevant clinical and non-clinical groups.

"Mmm, Smells like Coffee!": How a Brief Odor Identification Test Could Help to Identify People with Mild Cognitive Impairment and Dementia

(1) Background: Dementia and mild cognitive impairment (MCI) are still underdiagnosed in the general population. Impaired odor identification has been identified as an early marker of MCI and dementia. We aimed to compare the additional diagnostic value of two odor identification tests to a cognitive screening test in detecting MCI or dementia. (2) Methods: The Sniffin' Sticks odor identification test (SS-OIT), a brief odor identification test (B-OIT) requiring the identification of coffee scent, and the Mini-Mental State Exam (MMSE) were administered to a consecutive series of 174 patients (93 with dementia, 42 with mild cognitive impairment, and 39 without cognitive impairment) referred for neuropsychological testing. (3) Results: Both participants with dementia and with MCI exhibited impairments in odor identification. The SS-OIT and the B-OIT were substantially correlated. Complementing MMSE scores with the SS-OIT or the B-OIT similarly improved the diagnostic accuracy of individuals with dementia and MCI. (4) Conclusions: People with suspected dementia or MCI may already benefit from brief odor identification tests. Although these tests require little additional time, they can notably increase sensitivity for dementia or MCI.

Sharing Perceptual Experiences through Language

The aim of this article is to shed light on how sensory perceptions are communicated through authentic language. What are the language resources available to match multimodal perceptions, and how do we use them in real communication? We discuss insights from previous work on the topic of the interaction of perception, cognition, and language and explain how language users recontextualise perception in communication about sensory experiences. Within the framework of cognitive semantics, we show that the complexities of multimodal perception are clearly reflected in the multifunctional use of words to convey meanings and feelings. To showcase the language resources employed, we base our findings on research on how architects convey their perceptions of built space. Two main patterns emerge: they use multimodal expressions (soft, bland, and jarring) and descriptions of built space through motion (the building reaches out, or routes and directions such as destination, promenade, route, or landscape in combination with verbs such as start and lead) in which case the architect may either be the observer or the emerged actor. The important take-home message is that there is no neat and clear a priori link between words and meanings, but rather "unforeseen" patterns surface in natural production data describing sensory perceptions.