A systematic review of olfactory related questionnaires and scales

Odor awareness modulates the association between perceived stress and chemosensory anhedonia in women

Chronic stress alters reward sensitivity and contributes to anhedonia. Chemosensation is dominated by a hedonic dimension, but little is known about the association between chronic perceived stress and hedonic chemosensation in non-clinical populations. In the current study, 325 participants (201 females) completed a questionnaire-based survey measuring their chronic perceived stress (Perceived Stress Scale; PSS), chemosensory pleasure (Chemosensory Pleasure Scale; CPS), and olfactory metacognitive abilities (odor awareness, affective impact of odor, importance of olfaction). For females, higher PSS scores significantly predicted lower CPS scores, which is mediated by the positive odor awareness. Moreover, negative odor awareness was identified as a moderator underlying the relationship between PSS and CPS scores in females  but not in males. For females, higher PSS predicted lower CPS for those with lower, but not for those with higher levels of negative odor awareness. These results show that the link between chronic perceived stress and chemosensory anhedonia is pronounced in females, with olfactory perception playing a key role. The current study provides insights into the understanding of stress-related anhedonia and into the development of effective treatments.

Validation and cross-cultural adaptation of the Arabic version of the self-reported mini olfactory questionnaire (Self-MOQ)

Background

A simple self-assessment screening questionnaire for olfactory dysfunction is direly needed in Rhinology practice, and this questionnaire should be accessible to affected individuals. The self-reported mini olfactory questionnaire (Self-MOQ), constructed to fill this gap, could be an important tool, especially in the era of telemedicine.

Objectives

The aim of this study was to assess the validity and reliability of the Arabic version of the self-reported mini olfactory questionnaire (Self-MOQ) in patients with olfactory dysfunction.

Methodology

This cross-sectional study included all adult patients who visited a rhinology clinic between January and June 2023 with a complaint of olfactory dysfunction and a control group. The participants completed a questionnaire that included items on demographics, risk factors of olfactory dysfunction, the olfaction VAS, SNOT-22, and Arabic Self-MOQ. The Self-MOQ was forward- and back-translated by qualified professional translators familiar with American English and Arabic.The reliability of the Arabic Self-MOQ was evaluated using Cronbach's α. The test-retest reliability was assessed by estimating the intraclass correlation coefficient (ICC) for the total Arabic Self-MOQ score and the individual items. The discriminative ability was examined by comparing the scores of the case and control groups. The construct validity was assessed by comparing the Arabic Self-MOQ to the olfaction VAS.

Results

The study sample included 307 respondents (196 cases and 111 controls; 34 undertook the retest). The Cronbach's α coefficients were 0.92 (total Self-MOQ) and considered excellent. The ICC for the total Self-MOQ score was 0.87 (95% CI: 0.757, 0.933; p < .001), which indicated good test-retest reliability. Strong correlations were observed between the Self-MOQ items and VAS scores (r = 0.732, p < .001), (r = 0.689, p < .001).

Conclusion

The current investigation showed the Arabic version of the Self-MOQ to be a reliable tool for olfactory dysfunction screening.

Olfactory Dysfunction Following Moderate to Severe Traumatic Brain Injury: A Systematic Review and Meta-Analysis

OBJECTIVE

Reports of smell loss following traumatic brain injury (TBI) are a well-documented but understudied phenomenon. Given the broad consequences of olfactory loss, we characterized psychophysical olfactory dysfunction in individuals with moderate to severe TBI using systematic review and meta-analytic methods.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) protocol, five databases (PubMed, EMBASE, Cochrane Library, Web of Science, Scopus) were reviewed for studies investigating olfactory dysfunction in persons with moderate to severe TBI. Of the 5,223 studies reviewed, 19 met our inclusion criteria for the systematic review and 11 met inclusion criteria for meta-analysis. We calculated effect sizes (Hedges' g) to characterize the degree of olfactory dysfunction between patients with moderate to severe TBI and controls.

RESULTS

A total of 951 moderate-severe TBI patients from 19 studies were included in the systematic review, which largely demonstrated poorer olfactory psychophysical performances in this patient population. Meta-analysis demonstrated a large effect size for olfactory dysfunction in moderate-severe TBI relative to healthy controls (g=-2.43, 95%CI: -3.16 < δ<-1.69). The magnitude of the effect was moderated by age and patient sex, with larger effect sizes associated with older age (following exclusion of a pediatric population) and larger compositions of women in the patient group.

CONCLUSION

Moderate to severe TBI is associated with prominent olfactory dysfunction. Significant research gaps remain regarding the mechanism, recovery and natural history of olfactory dysfunction following moderate to severe TBI, which has significant clinical implications for the identification and treatment for those with post-traumatic olfactory dysfunction.

A parosmia severity index based on word-classification predicts olfactory abilities and impairment

Parosmia is an olfactory disorder that involves distortions of specific odors that may co-occur with anosmia, loss of smell of other odors. Little is known about which odors frequently trigger parosmia, and measures of parosmia severity are lacking. Here, we present an approach to understand and diagnose parosmia that is based on semantic properties (e.g., valence) of words describing odor sources ("fish", "coffee", etc.). Using a data-driven method based on natural language data, we identified 38 odor descriptors. Descriptors were evenly dispersed across an olfactory-semantic space, which was based on key odor dimensions. Parosmia patients (n = 48) classified the corresponding odors in terms of whether they trigger parosmic or anosmic sensations. We investigated whether these classifications are related to semantic properties of the descriptors. Parosmic sensations were most often reported for words describing unpleasant odors of inedibles that are highly associated to olfaction (e.g., "excrement"). Based on PCA modeling, we derived the Parosmia Severity Index-a measure of parosmia severity that can be determined solely from our non-olfactory behavioral task. This index predicts olfactory-perceptual abilities, self-reported olfactory impairment, and depression. We thus provide a novel approach for investigating parosmia and establishing its severity that does not require odor exposure. Our work may enhance our understanding of how parosmia changes over time and how it is expressed differently across individuals.

How to manage recurrences after surgery in CRSwNP patients in the biologic era: a narrative review

Objective

This narrative review analyses factors affecting recurrence of Chronic rhinosinusitis with nasal polyps (CRSwNP) after surgery, such as type, extension and completeness of endoscopic sinus surgery (ESS). We also described new implications in the management of recurrences after the advent of biologics.

Methods

We identified four topics: definition of disease state; factors linked to recurrence of polyps; evaluation and management of recurrence in clinical practice.

Results

We analysed the differences between exacerbation and recurrence, as well as the concept of "controlled disease". We focused on potential predictors of recurrence after ESS, such as type 2 inflammation, asthma, aspirin-exacerbated respiratory disease, incomplete initial surgery and lack of adherence to long-term post-operative local corticosteroids. We discussed the new aspects of diagnosis and treatment of recurrences after surgery, summarising our suggestions in a detailed algorithm for practical management of patients with recurrent disease.

Conclusions

The results emphasised the importance of accurate evaluation of patients with CRSwNP recurrence, focusing on the reasons of failure and risk of disease progression, in order to guide personalised interventions. It is crucial to define the concept of appropriate surgery, which affects the choice between starting a biologic or repeating surgery.

Development of a Self-reported Olfactory Dysfunction Questionnaire (SODQ) to screen olfactory disorders in China

BACKGROUND

The diagnosis of olfactory dysfunction is challenging given the negligence during routine physical examination, inconvenience of diagnosis in clinical practice, and the inattention to cross-cultural adaptability. The study aimed to develop and validate a simple and effective self-reported olfactory dysfunction questionnaire (SODQ) for the initial screening of clinical olfactory disorders in China.

METHODS

A total of 121 subjects participated in the study; of these, 96 subjects completed the T&T olfactometer test and 12-item questionnaire, and 25 participants were retested using the SODQ after one week. The T&T olfactometer test examined the olfactory function and the questionnaire measured the ability to perceive common odors in daily life. We evaluated the factor structure, reliability, validity, and discriminative ability of the SODQ.

RESULTS

The final version of the SODQ consisted of 10 items with one factor. Test-retest and internal consistency were excellent. Convergent validity of the questionnaire with the T&T olfactory test was high. Furthermore, the discrimination ability was high for the questionnaire with an area under the curve of 0.95 and a cut-off point of 22.

CONCLUSIONS

The SODQ is a brief, valid, and repeatable tool that has the potential to effectively screen for clinical olfactory disorders from a subjective perspective.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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