TDI Score Research Articles

Presurgical olfactory function as an indicator of the outcome of functional endoscopic sinus surgery in chronic rhinosinusitis with nasal polyps

IntroductionChronic rhinosinusitis with nasal polyps (CRSwNP) often leads to impaired olfactory function and reduced quality of life. When conservative treatments such as nasal irrigation and topical steroids fail, functional endoscopic sinus surgery (FESS) is often necessary, because it improves symptoms and enhances quality of life.Materials and methodsA total of 88 patients was included in this prospective study. All subjects underwent an extensive examination both presurgically and 4 months after operations including nasal endoscopy and psychophysical olfactory testing (Sniffin’ Sticks). Moreover, disease-specific quality of life was assessed and presurgical CT scans were rated regarding the opacification of the paranasal sinuses.ResultsPresurgically psychophysical tests showed an overall olfactory dysfunction. Olfactory test results (TDI score) correlated with endoscopic (Lund–Kennedy and Lildtholdt score) and CT scores (Lund–Mackay and TOCS scores). Four months after surgery olfactory function was enhanced and quality of life significantly showed an overall improvement. However, the outcome was dependent on the extent of presurgical olfactory function: olfaction and quality of life improved most pronounced in anosmics compared to hyposmic and especially normosmic patients.ConclusionsThis study confirmed that FESS in CRSwNP leads to a significant improvement of both olfaction and disease-specific quality of life. Moreover, preoperative psychophysical assessment of the extent of olfactory dysfunction can help to objectively assess possible risks and expected benefits of the surgery in terms of olfaction and quality of life.

Predictive significance of the questionnaire of olfactory disorders-negative statements for olfactory loss in patients with chronic rhinosinusitis.

ObjectivesThe questionnaire of olfactory disorder-negative statements (QOD-NS) is a valid and reliable instrument for assessing the olfactory-specific quality of life. This study aimed to explore the association between the QOD-NS and objective olfactory metrics (including objective olfactory cleft assessment) and then evaluate the predictive significance of the QOD-NS for olfactory loss in Chinese patients with chronic rhinosinusitis (CRS).MethodsA total of 70 patients with CRS were enrolled in the study. Olfaction was assessed with Sniffin’ Sticks. The olfactory cleft was assessed by the sinus CT scan and nasal endoscopy (the Lund–Mackay olfactory cleft scale, LM-OC and olfactory cleft endoscopy scale, OCES). The QOD-NS and its short version were utilized to assess the patient-reported olfaction. The predictors associated with olfactory loss were analyzed by the logistic regression analysis. The optimal cutoff points of the predictors were determined by the receiver-operating characteristic curves and the Youden index.ResultsThe TDI score in patients with CRS significantly correlated with the QOD-NS (r = − 0.755, P < 0.001), OCES (r = − 0.520, P < 0.001), LM-OC (r = − 0.615, P < 0.001). After adjusting for patient demographics and comorbidities, QOD-NS was significantly associated with olfactory dysfunction [odds ratio (OR) = 1.243; P = 0.001] and anosmia in patients with CRS (OR = 1.838; P = 0.006). Furthermore, the QOD-NS significantly correlated with the LM-OC (r = 0.610, P < 0.001), and the OCES (r = 0.464, P < 0.001) in patients with CRS. The QOD-NS had the highest predictive value for olfactory dysfunction (optimal cutoff = 10.5; Youden index = 0.635; area under the curve = 0.861) and anosmia (optimal cutoff = 20.5; Youden index = 0.790; area under the curve = 0.928) in patients with CRS.ConclusionThe QOD-NS showed high validity and correlated well with objective olfactory metrics and olfactory cleft assessment in patients with CRS. The QOD-NS was a reliable predictor for olfactory dysfunction and anosmia in patients with CRS, which may aid in the fast screening of olfactory loss in the clinic.

Olfactory Training in Post-COVID-19 Persistent Olfactory Disorders: Value Normalization for Threshold but Not Identification.

(1) Background: Persistent post-viral olfactory disorders (PPVOD) are estimated at 30% of patients one year after COVID-19 infection. No treatment is, to date, significantly effective on PPVOD with the exception of olfactory training (OT). The main objective of this work was to evaluate OT efficiency on post-COVID-19 PPVOD. (2) Methods: Consecutive patients consulting to the ENT department with post-COVID-19 PPVOD were included after completing clinical examination, the complete Sniffin’ Stick Test (TDI), the short version of the Questionnaire of olfactory disorders and the SF-36. Patients were trained to practice a self-olfactory training with a dedicated olfactory training kit twice a day for 6 months before returning to undergo the same assessments. (3) Results: Forty-three patients were included and performed 3.5 months of OT in average. We observed a significant TDI score improvement, increasing from 24.7 (±8.9) before the OT to 30.9 (±9.8) (p < 0.001). Based on normative data, a significant increase in the number of normosmic participants was observed only for the threshold values (p < 0.001). Specific and general olfaction-related quality of life improved after the OT. (4) Conclusions: Olfactory function appeared to improve only in peripheral aspects of post-COVID-19 PPVOD after OT. Future controlled studies must be performed to confirm the OT role and justify new therapeutic strategies that may focus on the central aspects of post-COVID-19 PPVOD.

Olfactory dysfunction in patients with multiple sclerosis; A systematic review and meta-analysis.

BackgroundThe importance and prevalence of olfactory dysfunction is recently gaining attention in patients with multiple sclerosis (MS) as a result of their chronic inflammatory disease, yet different prevalence rates are reported for it. Therefore, we have designed this systematic review to estimate the pooled prevalence of olfactory dysfunction in patients with MS. To our knowledge, this is the first systematic review and meta-analysis on the prevalence of olfactory dysfunction in MS patients.MethodsWe searched PubMed, Scopus, EMBASE, Web of Science, ProQuest, and gray literature including references from the identified studies, review studies, and conference abstracts which were published up to January 2021. Articles that were relevant to our topic and could provide information regarding the prevalence of olfactory dysfunction, or the scores of smell threshold, discrimination, or identification (TDI) among MS patients and healthy individuals were included. The pooled prevalence was calculated using a random-effects model and a funnel plot and Egger’s regression test were used to see publication bias.ResultsThe literature search found 1630 articles. After eliminating duplicates, 897 articles remained. Two conference abstracts were included for final analysis. A total of 1099 MS cases and 299 MS patients with olfactory dysfunction were included in the analysis. The pooled prevalence of olfactory dysfunction in the included studies was 27.2%. Also, the overall TDI score in MS patients was lower than that in the control group, and the level of Threshold, Discrimination, and Identification per se were lower in MS compared with control respectively.ConclusionThe results of this systematic review show that the prevalence of olfactory dysfunction in MS patients is high and more attention needs to be drawn to this aspect of MS.

Taste and smell function in long-term survivors after childhood medulloblastoma/CNS-PNET

PurposeTo investigate taste and smell function in survivors, with a minimum of 2 years since treatment of childhood medulloblastoma (MB)/central nervous system supratentorial primitive neuroectodermal tumor (CNS-PNET).MethodsThis cross-sectional study included 40 survivors treated ≤ 20 years of age. Taste strips with four concentrations of sweet, sour, salt, and bitter were used to assess taste function in all participants. Score from 0 to 16; ≥ 9 normogeusia, < 9 hypogeusia, and complete ageusia which equals no sensation. No sensation of a specific taste quality equals ageusia of that quality. Thirty-two participants conducted smell testing using three subtests of Sniffin’ sticks: threshold, discrimination, and identification. Together they yield a TDI-score from 1 to 48; functional anosmia ≤ 16.00, hyposmia > 16.00– < 30.75, normosmia ≥ 30.75– < 41.50, and ≥ 41.50 hyperosmia. Results were compared with normative data. Survivors rated their taste and smell function using a numerical rating scale (NRS) score 0–10.ResultsForty survivors with a mean time since treatment of 20.5 years, 13 (32.5%) were diagnosed with hypogeusia, nine (22.5%) of these being ageusic to one or more taste qualities. Seventeen (53%) of 32 participants were diagnosed with hyposmia. The mean scores of the olfactory subtests, and TDI score were significantly lower than normative data (P < 0.0001). The mean NRS scores of smell and taste function were 7.9 ± 1.5 and 8 ± 1.3, respectively.ConclusionOur study showed impaired taste and smell function in survivors of childhood MB/CNS-PNET using objective measurements. However, subjective ratings did not reflect objective findings.

Adjunctive Inspiratory Muscle Training During a Rehabilitation Program in Patients With Breast Cancer: An Exploratory Double-Blind, Randomized, Controlled Pilot Study

ObjectiveTo investigate whether inspiratory muscle training (IMT) offered adjunctively to an exercise training program reduces symptoms of dyspnea in survivors of breast cancer. DesignDouble-blind, parallel-group, randomized controlled trial. SettingOutpatient rehabilitation program in a university hospital. ParticipantsNinety-eight female patients with breast cancer who completed adjuvant treatment and subsequently entered cancer rehabilitation were screened for participation. Inclusion criteria were reduced inspiratory muscle strength and/or symptoms of dyspnea. Twenty patients (N=20) were randomly assigned to an intervention group (n=10) or a control group (n=10). InterventionBoth groups received a 3-month exercise training program in combination with either IMT (intervention) or sham-IMT (control). Main Outcome MeasuresChanges in dyspnea intensity perception (10-point Borg Scale) at comparable time points (isotime) during constant work rate cycling was the primary outcome. Secondary outcomes included changes in respiratory muscle function, exercise capacity, and changes in symptoms of dyspnea during daily life (Transitional Dyspnea Index [TDI]). ResultsThe intervention group achieved a larger reduction in exertional dyspnea at isotime compared with the control group (−1.8 points; 95% CI, −3.7 to 0.13; P=.066). The intervention group also exhibited larger improvements in dyspnea during daily life (TDI score, +2.9 points; 95% CI, 0.5-5.3; P=.022) and improved both respiratory muscle endurance (+472 seconds; 95% CI, 217-728; P=.001) and cycling endurance (+428 seconds; 95% CI, 223-633; P=.001) more than the control group. ConclusionsBecause of the limited sample size all obtained findings need to be interpreted with caution. The study offers initial insights into the potential of adjunctive IMT in selected survivors of breast cancer. Larger multicenter studies should be performed to further explore the potential role and general acceptance of this intervention as a rehabilitation tool in selected patients after breast cancer treatment.

Relationship between Olfactory Function and BMI in Normal Weight Healthy Subjects and Patients with Overweight or Obesity.

Smell plays a critical role in food choice and intake by influencing energy balance and body weight. Malnutrition problems or modified eating behaviors have been associated with olfactory impairment or loss. The obesity epidemic is a serious health problem associated with an increased risk of mortality and major physical comorbidities. The etiopathogenesis of obesity is complex and multifactorial, and one of the main factors contributing to the rapid increase in its incidence is the environment in which we live, which encourages the overconsumption of foods rich in energy, such as saturated fats and sugars. By means of the “Sniffin’ Sticks” test, we measured the olfactory threshold, discrimination and identification score (TDI score) in patients of the Obesity Center of the University Hospital (OC; n = 70) and we compared them with that of healthy normal weight controls (HC; n = 65). OC patients demonstrated a significantly lower olfactory function than HC subjects both general and specific for the ability to discriminate and identify odors, even when they were considered separately as females and males. For OC patients, a negative correlation was found between body mass index (BMI) and olfactory scores obtained by each subject, both when they were divided according to gender and when they were considered all together. Besides, normosmic OC patients showed a significantly lower BMI than hyposmic ones. A reduced sense of smell may contribute to obesity involving the responses of the cephalic phase, with a delay in the achievement of satiety and an excessive intake of high-energy foods and drinks.

Modified Olfactory Training Is an Effective Treatment Method for COVID-19 Induced Parosmia.

ObjectivesCoronavirus disease (COVID‐19) infection often causes olfactory dysfunction and parosmia may occur in some patients with olfactory dysfunction. In this study, we retrospectively investigated the effectiveness of modified olfactory training (MOT) for the treatment of COVID‐19‐induced parosmia.Study DesignThis study presents results of MOT performed with 12 odors for 36 weeks in patients with olfactory dysfunction following COVID‐19 infection. A total of 75 participants were included in the study (mean age 33 years, range 16–60 years).MethodsThe patients were separated into two groups: 1) Treatment group consisted of parosmia patients who received MOT with three sets of four different odors sequentially. 2) Control group consisted of parosmia patients who did not perform any olfactory training. Both groups were matched for age and sex distribution of participants. TDI scores were compared at the time of application and at the end of the 9th month by the Sniffin' Sticks Test. The results of the 0th and 9th months were recorded by applying the parosmia assessment scale to both groups. The results were analyzed statistically, and p < 0.05 was considered significant.ResultsWhen the treatment group and the control group were compared, a significant improvement was observed in both groups at the third, sixth, and ninth month, however the improvement in the treatment group was found to be better than in the control group (P < .001). Extending the treatment from 6 to 9 months in the treatment group was found to be effective in mitigating parosmia complaints and improving discrimination scores (P < .001).ConclusionThis study has shown that modified olfactory training is effective in the treatment of parosmia following COVID‐19 infection.Level of Evidence3 Laryngoscope, 132:1433–1438, 2022

Development of a novel centrifugal extraction device to collect the olfactory cleft mucus

Background Measuring olfactory cleft mucus biomarkers provides critical insights into the pathogenesis of the olfactory dysfunction. Objectives This study aimed to develop a novel centrifugal extraction device to collect the olfactory cleft mucus. Material and methods The olfactory cleft mucus was collected from 18 patients with chronic rhinosinusitis (CRS) and 10 healthy controls using polyvinyl alcohol (PVA) sponges. Both novel centrifugal extraction devices and traditional devices which consisted of a falcon tube and a syringe shaft were utilized. Levels of Galectin-10 were assessed using the enzyme-linked immunosorbent assay. The olfaction was evaluated with Sniffin’ Sticks. Results The average extraction efficiency of recovered volume for novel centrifugal extraction devices and traditional devices was 85.44 and 79.15%, respectively. Galectin-10 levels of the olfactory cleft mucus in patients with CRS were significantly higher than that in controls when extracted through novel devices (p < .001). Furthermore, levels of Galectin-10 in patients with CRS significantly correlated with TDI score (p = .020, r = −0.546). There was no significant difference between novel and traditional devices regarding Galectin-10 levels in CRS (p = .966). Conclusions and significance The novel centrifugal extraction device with PVA sponges proved to be a feasible method to collect the olfactory cleft mucus.

Olfactory Impairment in Parkinson's Disease Patients with Tremor Dominant Subtype Compared to Those with Akinetic Rigid Dominant Subtype: A Pilot Study.

Background: Parkinson’s disease (PD) may present different motor subtypes depending on the predominant symptoms (tremor or rigidity/bradykinesia). Slower disease progression and cognitive decline were observed in tremor-dominant (TD) patients compared to those with the akinetic-rigid dominant (ARD) subtype. Although olfactory dysfunctions are well-known disturbances in PD patients, correlations among PD different subtypes and olfactory impairment were not clearly studied. Thus, we investigated the possible olfactory impairment in PD patients with TD and ARD subtypes as compared to healthy controls. Methods: A sample of 132 participants were enrolled: 62 PD patients divided into ARD (n = 42) and TD (n = 20) subgroups using tremor/rigidity ratio, and 70 healthy controls. Olfactory function was assessed with the Sniffin’ Sticks Test. Results: Odor threshold was significantly lower in the ARD than in the TD subtype, while odor identification, discrimination scores, and their sum (TDI score) were not significantly different. On multivariate linear regression analysis, the tremor/rigidity ratio was a significant predictor of odor threshold. Conclusions: Our pilot study showed a significant olfactory dysfunction in PD patients with the ARD subtype. This evidence confirms the biological relevance of clinical subgroups in PD patients, suggesting the existence of a different pathophysiological mechanism between the ARD and TD clinical subtypes.

Olfactory Dysfunction in COVID-19 Patients Who Do Not Report Olfactory Symptoms: A Pilot Study with Some Suggestions for Dentists.

Background: Smell and taste dysfunction are frequently reported by SARS-CoV-2 positive patients. The degree of olfactory and gustatory dysfunction varies from a very mild reduction to their complete loss. Several studies have been performed to determine their prevalence in COVID-19 patients, mostly using subjective measurement methods. The literature lacks long-term studies regarding duration and recovery. Methods: We assessed olfactory performance, using the Sniffin’ Sticks olfactory test, in a group of patients who had not reported olfactory dysfunction, around 131 days after their COVID-19 diagnosis. Results: 11 out of 20 subjects showed no olfactory reduction (65%), while 9 subjects showed reduced TDI score (45%). A total of 13 subjects (65%) scored above the cutoff point for Threshold, 16 subjects (80%) scored above the cutoff point for discrimination and 13 subjects (65%) scored above the cutoff point for identification. Conclusion: Objective measurement methods of olfactory performance show a higher prevalence of olfactory reduction compared to patients’ self-reported questionnaires. Olfactory dysfunction can last even months after its onset and because of its high prevalence, it could be a screening symptom for suspect COVID-19 cases.

Analysis of Diagnostic Value of Electrogastrography for Parkinson's Disease and its Predictive Value for the Disease Progression.

The study aimed to evaluate the diagnostic and prognostic value of indexes detected by electrogastrography in Parkinson's disease patients. One hundred twenty early Parkinson's disease patients and 120 healthy controls were recruited, and underwent electrogastrography to detect dominant frequency (DF), instability coefficient of DF (ICDF), low frequency range (LFR), high frequency range (HFR), and normal frequency range (NFR). The receiver operating characteristic (ROC) curve was drawn for the diagnostic value analysis. The motor function was scored with the Unified Parkinson's Disease Rating Scale (UPDRS). Sniffin' Sticks test was used for the olfactory evaluation, and the TDI score consisting of odor threshold (T), odor discrimination (D) and odor identification (I) tests was calculated. The preprandial ICDF of Parkinson's disease patients was significantly higher than that of the control group, and decreased slowly during the late postprandial phase. The levels of LFR%, HFR% and NFR% in Parkinson's disease patients were higher than the control group during both the preprandial and late postprandial phase, and the changes of each index before and after meals were not obvious. Preprandial ICDF value and TDI score had the ability to distinguish Parkinson's disease patients with the AUC of 0.874 and 0.859 respectively. The ICDF detected by electrogastrography has high clinical value in the early diagnosis of Parkinson's disease, and the combination of ICDF and TDI can improve the diagnostic sensitivity and specificity of a single indicator. High ICDF levels during the preprandial phase are related to the poor prognosis of Parkinson's disease patients after treatment.

Use of the Diet History Questionnaire III to determine the impact of dysosmia on dietary quality.

Dysosmia could alter dietary quality through mechanisms including changes in appetite, food choice, and subsequent nutritional intake. However, there are few studies that directly assess olfactory performance and dietary quality. In this pilot study, we aimed to measure dietary quality in patients with dysosmia compared with controls with normosmia. Community-dwelling adults prospectively underwent olfactory testing using the Sniffin' Sticks test from which composite threshold, discrimination, and identification (TDI) scores were used to identify patients with dysosmia (TDI<31) and controls with normosmia (TDI≥31). Participants completed the Diet History Questionnaire III (DHQ III), a standardized and validated tool for nutritional assessment developed by the National Institutes of Health. The Healthy Eating Index (HEI) was calculated to determine compliance with the US Dietary Guidelines for Americans. Sixty patients were enrolled, including 29 patients with dysosmia and 31 controls with normosmia with no difference in age or sex among groups. A significant correlation between TDI score and HEI component score was seen for protein (r=0.256; p=0.048), dairy (r=0.285; p=0.027), and saturated fat (r=-0.262; p=0.043) scores. Compared with controls with normosmia, patients with dysosmia were found to have less total protein and total dairy intake, as well as less total saturated fat intake. This study found significantly altered nutritional quality in patients with reduced olfactory function, including decreased intake of protein, dairy, and saturated fats. These findings are relevant given the high prevalence of dysosmia in the aging population and previous studies showing associations with mortality.

Olfactory function testing before and after anesthesia

This study aimed to determine whether anesthesia would affect olfactory function. Patients who were admitted for surgical intervention that did not include the nasal cavity and paranasal sinuses were included in this prospective cohort study. Structured medical history was taken from the patients, including the following: age, sex, smoking history, alcohol intake, current medications, and sleep deficits prior to surgery. Before surgery, patients were asked for a self-rating of their olfactory function. Olfactory function was also measured using Sniffin’ Sticks comprising measures of odor threshold, discrimination, and identification. The mean interval between olfactory tests was 6 days (range 3–12 days). Seventy-three patients were included in the study, 34 men and 39 women. Olfactory scores were consistent before and after surgery as indicated by correlative analyses (p < 0.05). Odor thresholds, discrimination, identification, and composite TDI scores did not change significantly, whereas odor identification scores increased (p = 0.011) after surgery. In conclusion, post-operative olfactory scores remained stable. However, identification scores exhibited a slight increase which can be attributed to a retest effect. Overall, the present results indicate that surgery outside of the nasal and paranasal sinus region performed in general anesthesia has no major effect on the sense of smell.

Prevalence of Persistent Olfactory Disorders in Patients With COVID-19: A Psychophysical Case-Control Study With 1-Year Follow-up.

The purpose of this multicenter case-control study was to evaluate a group of patients at least 1 year after coronavirus disease 2019 (COVID-19) with Sniffin' Sticks tests and to compare the results with a control population to quantify the potential bias introduced by the underlying prevalence of olfactory dysfunction (OD) in the general population. The study included 170 cases and 170 controls. In the COVID-19 group, 26.5% of cases had OD (anosmia in 4.7%, hyposmia in 21.8%) versus 3.5% in the control group (6 cases of hyposmia). The TDI score (threshold, discrimination, and identification) in the COVID-19 group was significantly lower than in the control group (32.5 [interquartile range, 29-36.5] vs 36.75 [34-39.5], P < .001). The prevalence of OD was significantly higher in the COVID-19 group, confirming that this result is not due to the underlying prevalence of OD in the general population.

Pulmonary rehabilitation for idiopathic pleuroparenchymal fibroelastosis: A retrospective study on its efficacy, feasibility, and safety.

The beneficial effects of pulmonary rehabilitation (PR) for patients with idiopathic pleuroparenchymal fibroelastosis (IPPFE) remain unknown. This study aimed to examine the efficacy, feasibility, and safety of PR for IPPFE. We retrospectively investigated 25 patients with IPPFE referred for PR between April 2007 and March 2017. The PR mainly consisted of a 10-week exercise training program. The primary outcome was a change in 6-min walk distance (6MWD). Secondary outcomes included changes in dyspnea (transition dyspnea index [TDI]), anxiety and depression (hospital anxiety and depression scale [HADS]), and health-related quality of life (HRQoL) (St George's respiratory questionnaire [SGRQ]). Thirteen patients participated in the PR program (PRP). Recurrent pneumothorax was the most common reason for patients not participating in the PRP. Four patients discontinued the PRP due to the recurrence of pneumothorax, new onset of pneumomediastinum, stroke, and another reason, respectively. Nine patients completed the PRP. Significant improvement was observed in 6MWD (median [interquartile range], 90m [55-116m]; P=0.033). Clinically important improvements in the 6MWD, and TDI, HADS-anxiety, HADS-depression, and SGRQ total domain scores were observed in seven (78%), five (56%), four (44%), four (44%), and five (56%) of the nine patients, respectively. Patients with IPPFE benefited from PR in terms of exercise capacity, dyspnea, anxiety, depression, and HRQoL. Pneumothorax and pneumomediastinum may impede the implementation of a PRP for patients with IPPFE. While careful patient selection is required, PR may be an efficacious non-pharmacological approach for managing disabilities in patients with IPPFE.

Olfaction in COPD.

Olfaction is poorly characterized in COPD. To test the hypothesis that olfaction is reduced in COPD, we assessed olfaction with the "Sniffin' Sticks" test and a questionnaire addressing olfaction in COPD and a corresponding control group in respect to age and sex. We also explored whether there is an association between COPD, chronic rhinosinusitis without nasal polyps (CRSsNP), and other predefined covariates with olfactory function. Olfactory function was assessed by the score for threshold (T), discrimination (D) and identification (I), and the composite TDI score in the "Sniffin' Sticks" test and by self-reported evaluation of impaired olfaction and of "decreased sense of smell and taste" in the 22-item Sino-Nasal Outcome Test (SNOT-22) in 90 COPD patients and 93 controls. A clinical interview and ENT-examination with nasal endoscopy, skin prick test and spirometry with reversibility were performed. The TDI, D and I scores were significantly lower in the COPD group than in the control group. The T score was not significantly different between the two groups. Hyposmia and anosmia were present in up to 79% of patients with COPD. The prevalence of self-reported impaired olfactory function and for "decreased sense of smell and taste" - was more than two-fold greater in the COPD than in the control group. COPD, higher age, male sex and allergy were associated with a lower TDI score, while CRSsNP was not associated with the TDI score. COPD is associated with olfactory dysfunction and the underlying mechanisms for this dysfunction should be elucidated.

Olfactory dysfunction in passive vs active smoking.

BackgroundThe aim of this study is to assess the olfactory functions of passive smokers compared to active smokers and nonsmokers.MethodsThis prospective case‐control study included 30 nonsmokers, 30 passive smokers, and 30 active smoker participants. All groups were matched for gender and age. The Sino‐Nasal Outcome Test 22 (SNOT‐22) and Sniffin' Sticks test battery were administered to all subjects. Threshold (T), discrimination (D), and identification (I) scores were noted. Olfactory function was subjectively assessed as 0: severe dysfunction and 5: no problem.ResultsOverall, TDI scores of active smokers (24.78 ± 3.02) and passive smokers (24.90 ± 2.45) were significantly lower than nonsmokers (34.23 ± 3.46). There was no statistically significant difference between passive smokers and smokers (F (2,87) = 13.47, P < .001)). All subscores are negatively affected by active or passive smoking. The greatest impact of smoking was on threshold scores (η 2 T = 0.719), followed by identification (η 2 I = 0.353) and discrimination (η 2 D = 0.282) scores. SNOT‐22 and TDI scores were weakly (r = −.352) correlated as subjective assessment, and TDI scores were moderately correlated (r: .539) (P values < .001). Age and pack‐years cigarette dosage had a negative effect on the TDI score (TDI = 26.386 − (0.084 × age) − (0.072 × Pack.Year)) according to stepwise linear regression model (F = 10.187; P = .001).ConclusionsPassive smoking has nearly the same adverse effect on olfactory function as active smoking. The threshold scores are the most negatively affected. The olfactory effect of cigarette smoke may not be directly related to nasal inflammation. Olfactory neuronal pathways should be investigated to elucidate the exact pathophysiology.Level of Evidence3b.

Comparison of Olfactory Cleft Width and Volumes in Patients with COVID-19 Anosmia and COVID-19 Cases Without Anosmia

Introduction: The aim of this study was to assess the relationship between olfactory cleft width/volume and COVID-19-related anosmia. Methods: This study consisted of PCR-proven COVID-19 patients. Cases with COVID-19-related anosmia constituted Group 1 and cases without any olfactory dysfunction (OD) throughout COVID-19 infection or after recovery constituted Group 2. A total of 50 patients were included in the study, comprising 24 cases in Group 1 and 26 cases in Group 2. Group 1 patients underwent a 4-item-odor identification test during active symptoms and a Sniffin’ Sticks test after reconversion of PCR results to negative. All patients in Group 2 also underwent the Sniffin’ Stick test to document normosmia. All cases had paranasal sinus CT performed. Olfactory cleft widths and olfactory volumes were measured. The differences in width and volume between groups and the correlation with odor test scores (threshold-discrimination-identification [TDI]) were calculated. In addition, regression analyzes analysis was performed for cleft widths, volumes, and TDI scores according to age. Results: Olfactory cleft widths and olfactory volumes were significantly higher in Group 1 than those in Group 2 (p = 0.001; p < 0.01). There was a significant negative correlation between total TDI scores and olfactory cleft widths and total olfactory volumes (r = −0.665; r = −0.731, respectively). Patients younger than 40 years of age had significantly higher right olfactory cleft width, left olfactory cleft width, and olfactory cleft volume than those in patients older than 40 years of age (p = 0.004, p = 0.005, p = 0.003; p < 0,01, respectively). However, patients younger than 40 years of age had a significantly lower total TDI score and in all other values individually (t-d-i) than those in patients older than 40 years of age (p = 0.004; p < 0.01). Conclusion: Patients with COVID-19-related OD had larger olfactory cleft width and volumes than those without OD in this study. Total TDI score was found to be inversely correlated with cleft width and volume.

Association Between Anxious Symptom Severity and Olfactory Impairment in Young Adults with Generalized Anxiety Disorder: A Case-Control Study.

ObjectiveThe findings of olfaction are inconsistent in anxiety disorders, and few studies have reported on the olfactory performance in generalized anxiety disorder (GAD). Therefore, we aim to investigate the olfactory function of patients with GAD and the association between olfactory function and anxiety symptoms.MethodsWe conducted a case–control study by selecting 107 patients with GAD and 107 healthy controls matched for sex and age, to investigate olfaction deficits in GAD and the association between anxiety severity and olfaction. All patients were treatment-naïve prior to the inclusion. Anxiety severity and olfaction were assessed by the Hamilton anxiety rating scale (HAM-A) and the Sniffin’ Sticks test (SST), respectively. Partial correlations were used to analyze the relationship between olfaction and anxiety severity. False discovery rate (FDR) correction was used in multi-correlation analyses.ResultsCompared with healthy controls, patients in the GAD group demonstrated odor threshold, discrimination and identification deficits. In the moderate/severe anxiety subgroup, discrimination score was significantly and inversely correlated with the somatic anxiety score (γ=−0.44, q = 0.03), and identification score was significantly and inversely correlated with the HAM-A total score (γ=−0.42, q= 0.04). The TDI score (the sum of threshold, discrimination and identification scores) was significantly and inversely correlated with the somatic (γ=−0.44, q = 0.04) and psychic (γ=−0.45, q = 0.04) anxiety scores in the moderate/severe anxiety subgroup.ConclusionThis study demonstrated the olfactory impairment in patients with GAD and that poorer odor discrimination was correlated with greater severity of somatic anxiety.