Self-Reported Olfactory Outcomes in Transplanum and Transtuberculum Approaches

Objectives  The aim of this study was to determine the clinical characteristics and cephalometric risk factors associated with decreased postoperative olfaction in patients in whom the transplanum and transtuberculum expanded endonasal approach (EEA) was performed. Methods  A retrospective cohort of 41 patients treated with the transplanum and transtuberculum EEA was divided into two groups based on the maximum change in the postoperative 22-item Sino-Nasal Outcome Test (SNOT22) olfaction score: prolonged olfactory loss group ( n  = 5) with a ΔSNOT22 olfaction score of ≥ 4 without a return to baseline and a preserved olfaction group ( n  = 36) with a ΔSNOT22 olfaction score ≤ 3 with return to baseline on follow-up of at least 3 months. Demographics, operative details, and cephalometric measurements were compared between the two groups. Results  There were no differences in terms of the type of surgical approach (transplanum and transtuberculum), resection of turbinates (middle and superior), use of reconstructive flap (nasoseptal flap and reverse flap), or tumor pathology between the two groups. In the prolonged olfactory loss group, there was a smaller angle between the planum and the face of the sella (89.75 ± 9.18 vs. 107.17 ± 16.57 degrees, p  = 0.05) and a smaller angle between the anterior nasal spine and the sphenoid sinus face (21.20 ± 2.49 vs. 25.89 ± 4.90 degrees, p  = 0.047) compared with the preserved olfaction group. Conclusion  Patients with a narrow angle between the planum and the face of the sella or that between the anterior nasal spine and the sphenoid sinus face are at a higher risk of prolonged olfactory dysfunction with the transplanum and transtuberculum approaches. Level of Evidence  IV.

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.

Normative data for the Vietnamese smell identification test

Introduction

The 12-item Vietnamese smell identification test (VSIT) has been developed to evaluate the olfactory function of the Vietnamese population. This study aimed to investigate the normative value of the VSIT in different age groups and sexes.

Methods

This cross-sectional study was conducted at Ho Chi Minh University Medical Center, Vietnam. All participants were evaluated for odor identification ability using the VSIT. We included healthy participants aged 18 years or older with no history of olfactory disturbances.

Results

A total of 391 healthy volunteers were recruited with a mean age of 45.80 years (SD: 17.62; range: 18-86; female: 63.4 %). The tenth percentile of scores on the 0-12 VSIT scale was 8.3 in participants aged 18-29 years, 9.0 in 30-39 years, 8.0 in 40-49 years, 7.8 in 50-59 years, 7.9 in 60-69 years and 6.0 in over 70 years. Young adults (18-39 years old) had better olfactory identification ability than older adults (over 50 years), p < 0.001. There was a significant main effect of sex on VSIT score (p = 0.02), suggesting that females outperformed males. Sensitivity to 8 odors were negatively correlated with age: lemon, garlic, banana, coffee, mango, guava, apple and watermelon (p < 0.05 in all cases) whereas four odors were age-independent including orange, fish sauce, soy sauce, and fish.

Conclusion

Normative data provide guidance for assessing individual olfactory function. However, there were significant sex and age effects on olfactory identification scores on the VSIT. Therefore, future studies should be conducted to better adjust for those confounders mentioned above.

Validation of the local applicability of the 'TIB' Olfactory Test Device in the era of COVID-19

Objective

To evaluate the validity and test–retest reliability of the novel ‘TIB’ Olfactory Test Device (TIB) and to determine its normative values.

Methods

The study stratified the study subjects into normosmic, hyposmic and anosmic groups according to their olfactory function. The olfactory function of the subjects was evaluated using both the traditional Chinese version of the University of Pennsylvania of Smell Identification Test (UPSIT-TC) and the TIB. The normosmic group was used to retest with the UPSIT-TC and TIB at an inter-test interval of at least 7 days. The cut-off scores of TIB among the three different groups were determined by receiver operating characteristic curve analysis.

Results

This study enrolled 180 subjects: 60 in each group. The mean scores of TIB were 44.1 for the normosmic group, 27.5 for the hyposmic group and 10.9 for the anosmic group. The TIB scores were significantly different across the three groups. There was a significant correlation between the first and second TIB tests (r = 0.506). The cut-off scores were 41 for normosmic subjects and 24 for hyposmic subjects.

Conclusion

The validity and test–retest reliability results suggest that the TIB is an appropriate olfactory test for the Taiwanese population.

Olfactory Cleft Opacification in COVID-19 Related Smell Loss: CT Findings and Correlation With Objective Testing

OBJECTIVES

Besides the common symptoms of the coronavirus disease 2019 (COVID-19) including fever, shortness of breath, and cough, a "sudden loss of smell" has recently been added as a diagnostic symptom. The relationship between paranasal sinus computed tomography (PNS CT) and sudden loss of smell in COVID-19 was examined.

MATERIALS AND METHODS

Two groups were selected for the study, the COVID-19 and the control groups. The control group consisted of 40 patients who applied to our clinic with headache and therefore underwent PNS CT. The other group consisted of 40 patients with COVID-19 who were diagnosed with sudden loss of smell with the Connecticut Chemosensory Clinical Research Center (CCCRC) olfactory test. Clinical and demographic characteristics, tomography results, and olfactory test scores of patients with COVID-19 loss of smell and control group patients were recorded. The relationship between CT changes in the olfactory cleft and the degree of loss of smell was evaluated. The "Opacification in the olfactory cleft" was accepted as a positive CT finding.

RESULTS

Comparison of patients with COVID-19 who had a loss of smell and the control group indicated that a significant difference was observed in terms of CT findings (P = .022). When we evaluated the paranasal CTs obtained from our patients with loss of smell, the CT of 13 patients showed pathological findings (P < .05). As the COVID-19 progressed (pneumonia and respiratory failure), the degree of loss of smell increased (P < .05). A statistically significant relationship was found between the CCCRC score and the presence of PNS CT findings (P = .0012).

CONCLUSION

The PNS CT findings are significant in patients with COVID-19 with a loss of smell and were significantly associated with the degree of loss of smell. In patients with olfactory loss due to COVID-19, PNS CT can help in diagnosis. However, for this imaging to be diagnostic, a larger patient series is needed.

Quantitative evaluation and progress of olfactory dysfunction in COVID-19

Purpose

Since many different rates have been reported in the literature and the studies conducted are mostly based on the patient anamnesis, it was aimed to analyze the olfactory dysfunction in Coronavirus Disease 2019 (COVID-19) quantitatively and to reveal its progress by time.

Methods

Patients who described new-onset olfactory dysfunction, who were treated in the COVID-19 departments of our hospital and whose PCR tests demonstrated SARS-CoV-2 presence were included in the study and they were investigated prospectively. Clinical information of all the patients was taken and the levels of olfactory function were detected using the Brief Smell Identification Test (BSIT). Scores equal to or below 8 are considered as olfactory dysfunction. Patients who were followed up for 3 months were reevaluated with the BSIT test at the end of the third month and the progression of the symptom was investigated.

Results

The mean BSIT test score of the 42 patients (23 female patients, 19 male patients, mean age: 41.2 ± 14.6) was 5.2 ± 2.2. There was severe olfactory dysfunction in 16.7% of the patients (0–2 points), moderate olfactory dysfunction in 31% (3–5 points), and mild olfactory dysfunction in 52.4% (6–8 points). After a follow-up for 3 months, full recovery was observed in 36 patients (85.7%) and the mean test score rose to 9.9 ± 1.8. Although olfactory dysfunction persisted in 6 patients, an elevation in test scores was noted. Olfactory dysfunction was the first symptom in 17 patients (40%) and the other symptoms occurred after 2 days (1–6) on average.

Conclusion

We investigated olfactory dysfunction caused by COVID-19 using BSIT, and found a high rate of moderate-mild level symptoms with a high level of recovery in the 3-month follow-up. The finding revealing that olfactory dysfunction was the first symptom in 40% of the patients suggests the importance of inquiry on olfactory functions for the early diagnosis of the disease.

Olfactory Dysfunction in Huntington's Disease

Olfactory dysfunction is a common symptom in patients with neurodegenerative disorders, including Huntington's disease (HD). Understanding its pathophysiology is important in establishing a preventive and therapeutic plan. In this literature review, we cover the physiology of olfaction, its role in neurodegeneration, and its characteristics in patients with HD. In the general population, olfactory dysfunction is present in 3.8-5.8%and the prevalence increases significantly in those older than 80 years. For HD, data regarding prevalence rates are lacking and the scales used have been inconsistent or have been restructured due to concerns about cross-cultural understanding. Pathogenic huntingtin deposits have been found in the olfactory bulb of individuals with HD, although no studies have correlated this with the grade of olfactory impairment. Olfactory dysfunction is present in both premanifest and manifest patients with HD, showing a progressive decline over time with more severe deficits at advanced stages. No specific treatment for olfactory impairment in HD has been proposed; identifying and avoiding potential medications that cause olfactory dysfunction, as well as general safety recommendations remain the basis of the therapeutic strategy.

Correlation and agreement of olfactory perception assessed by the Connecticut Chemosensory Clinical Research Center olfactory test and the Brief-Smell Identification Test†

INTRODUCTION

Assessing olfactory perception in olfactory disorders is of utmost importance in therapy management. However, the University of Pennsylvania Smell Identification Test and the Sniffin' Sticks are the only tests validated in Brazil.

OBJECTIVES

To evaluate the correlation and agreement between the Chemosensory Clinical Research Center olfactory test and the Brief-Smell Identification Test - University of Pennsylvania Smell Identification Test - in healthy participants and in participants with olfactory disorders based on the results and technical aspects of both tests.

METHODS

Fifty participants without olfactory complaints and 50 participants with olfactory disorders who underwent the Chemosensory Clinical Research Center olfactory test and the Brief-Smell Identification Test were included. The following tests were used for statistical analysis: Mann-Whitney U test, Spearman's correlation, intraclass correlation coefficient and Bland-Altman plot. An alpha error (significance level) of 0.05 was considered in the statistical analysis.

RESULTS

Both tests were effective in distinguishing the groups without the presence of overlapping values ​​for the measured markers. Additionally, there was a strong correlation between Spearman's correlation and intraclass correlation coefficient between the tests and for both nostrils. However, the correlations were lower when the groups were individually evaluated. The Bland-Altman plot showed no bias when all participants were simultaneously evaluated.

CONCLUSIONS

The tests to assess olfactory perception presented a high level of agreement. In our sample, we could infer that the Connecticut Chemosensory Clinical Research Center olfactory test is similar to the Brief-Smell Identification Test and can be used in the routine diagnosis of patients with complaints of olfactory disorders, considering the advantage of its low cost.

Sex Differences in Human Olfaction: A Meta-Analysis

Although the view that women's olfactory abilities outperform men's is taken for granted, some studies involving large samples suggested that male and female olfactory abilities are actually similar. To address this discrepancy, we conducted a meta-analysis of existing studies on olfaction, targeting possible sex differences. The analyzed sample comprised n = 8 848 (5 065 women and 3 783 men) for olfactory threshold (as measured with the Sniffin Sticks Test; SST), n = 8 067 (4 496 women and 3 571 men) for discrimination (SST), n = 13 670 (7 501 women and 6 169 men) for identification (SST), and a total sample of n = 7 154 (3 866 women and 3 288 men) for works using University of Pennsylvania Smell Identification Test (UPSIT). We conducted separate meta-analyses for each aspect of olfaction: identification, discrimination and threshold. The results of our meta-analysis indicate that women generally outperform men in olfactory abilities. What is more, they do so in every aspect of olfaction analyzed in the current study. However, the effect sizes were weak and ranged between g = 0.08 and g = 0.30. We discuss our findings in the context of factors that potentially shape sex differences in olfaction. Nevertheless, although our findings seem to confirm the "common knowledge" on female olfactory superiority, it needs to be emphasized that the effect sizes we observed were notably small.

Development of an International Odor Identification Test for Children: The Universal Sniff Test

OBJECTIVE

To assess olfactory function in children and to create and validate an odor identification test to diagnose olfactory dysfunction in children, which we called the Universal Sniff (U-Sniff) test.

STUDY DESIGN

This is a multicenter study involving 19 countries. The U-Sniff test was developed in 3 phases including 1760 children age 5-7 years. Phase 1: identification of potentially recognizable odors; phase 2: selection of odorants for the odor identification test; and phase 3: evaluation of the test and acquisition of normative data. Test-retest reliability was evaluated in a subgroup of children (n = 27), and the test was validated using children with congenital anosmia (n = 14).

RESULTS

Twelve odors were familiar to children and, therefore, included in the U-Sniff test. Children scored a mean ± SD of 9.88 ± 1.80 points out of 12. Normative data was obtained and reported for each country. The U-Sniff test demonstrated a high test-retest reliability (r₂₇ = 0.83, P < .001) and enabled discrimination between normosmia and children with congenital anosmia with a sensitivity of 100% and specificity of 86%.

CONCLUSIONS

The U-Sniff is a valid and reliable method of testing olfaction in children and can be used internationally.

Optimizing olfactory testing for the diagnosis of Parkinson's disease: item analysis of the university of Pennsylvania smell identification test

The 40-item University of Pennsylvania Smell Identification Test (UPSIT) is an effective instrument to detect olfactory dusfunction in Parkinson's disease (PD). It is not clear, however, whether tests of this length are necessary to detect such dysfunction. Several studies have suggested that detection of certain odors is selectively compromised in PD, and that a test comprised of these odors could be shorter and more specific for this purpose. Therefore, we attempted to identify a subset of UPSIT odors that distinguish PD from controls with similar or improved test characteristics compared to the full test. The discriminatory power of each odor was examined using UPSIT data from a discovery cohort of 314 PD patients and 314 matched controls and ranked using multiple methods (including odds ratios, regression coefficients and discriminant analysis). To validate optimally discriminant subsets, we calculated test characteristics using data from two independent cohorts (totaling 306 PD and 343 controls). In the discovery cohort, multiple novel 12-item subsets (and the previously described Brief Smell Identification Test-B) performed similarly or improved upon the UPSIT and were better than 12 random items. However, in validation studies from independent cohorts, multiple subsets retained test characteristics similar to the full UPSIT, but did not outperform 12 random items. Differential discriminatory power of individual items is not conserved across independent cohorts arguing against selective hyposmia in PD. However, multiple 12-item subsets performed as well as the full UPSIT. These subsets could form the basis for shorter olfactory tests in the clinical evaluation of Parkinsonism.

Osmophobia and olfactory functions in patients with migraine

Olfactory dysfunction and migraine has been associated for a long time. In this study, we planned to compare olfactory functions in patients with migraine and osmophobia with patients having migraine but no osmophobia, in addition with a normal control group using "Sniffin' Sticks" test. The main distinction of this study is that all qualitative and quantitative properties of olfactory functions; threshold, discrimination and identification, are evaluated separately and jointly. Thirty healthy person aged between 16 and 56 (18 women, 12 men) and 60 migraine patients aged between 15 and 54 (39 women, 21 man) were included in the study. All patients have been inquired about osmophobia and have been assessed with Hedonic tone assessment. Osmophobia has been tested for perfume, cigarette smoke, leather, stale food, soy sauce, fish, spices and coffee smells. Olfactory functions has been assessed with "Sniffin' Sticks" smell test. Thresholds, discrimination and identification have been determined for each patient. In migraine patients with osmophobia, threshold was 7.75 ± 2.3, in migraine patients without osmophobia threshold was 8.25 ± 1.5 and threshold was 10.75 ± 1.3 for the control group. Discrimination score was 6 ± 1.2 in migraine patients with osmophobia, 9 ± 0.8 in patients without osmophobia and was 12 ± 1.4 in the control group. In migraine patient with or without osmophobia Threshold/Discrimination/Identification (TDI) scores were lower than the control group. The most important parameter in our study is that discrimination scores were especially lower in patients with osmophobia. We believe that this decrease in discrimination in migraine patients with osmophobia; who claim that they smell everything and they are sensitive to all smells, is significant. Further studies about smell discrimination will help better understand some conditions; especially anosmia and hyposmia after upper respiratory tract infections and parosmia.