Self-assessment of olfactory function using the "Sniffin' Sticks"

BACKGROUND

A precise and reliable test of the olfactory function is indispensable for the diagnosis of the olfactory disorder (OD). Despite of this, in a clinical context, often there is no place in daily routine for time-consuming procedures. This study aimed to examine if the assessment of olfactory function using the "Sniffin' Sticks" is suitable for self-assessment.

METHODS

Participants comprised 84 healthy control subjects (HC) and 37 OD patients. The "Sniffin' Sticks" test battery consisting of odor threshold (T), discrimination (D) and identification (I) tests was used for self- and assisted assessments. To save time, we applied the 8-item wide step version of the T test and the 8-item D test, whereas the I task remained the same as the original version. The whole test included two sessions, with each session comprising a self-assessment part performed by the participants themselves, and an assisted-assessment part performed by the examiner.

RESULTS

Sniffin' Sticks self-assessment was efficient in distinguishing between self-reported HC subjects and OD patients (p's < 0.01), and the scores did not differ significantly from the assisted-assessment (p's > 0.05). In the self-administered I and TDI tests, there was a moderate to excellent test-retest reliability (ICC = 0.51-0.93, p's < 0.01), and a strong to excellent correlation with the assisted assessment (r = 0.71-0.92, p's < 0.01). However, the self-administered T and D tests only exhibited low to moderate test-retest reliability (ICC = 0.30-0.72, p's < 0.05) and correlations with the assisted test (r = 0.31-0.62, p's < 0.05).

CONCLUSIONS

The Identification self-test is appropriate to be solely applied, and is therefore an easy-to-use alternative for olfactory screening in a larger segment of patients. The whole "Sniffin' Sticks" self-test also shows good measurement properties and is therefore a suitable backup in clinical practice, but improvement is needed due to the simplified D and T self-test.

A mobile APP-based, customizable automated device for self-administered olfactory testing and an implementation of smell identification test

Olfactory tests are used for the evaluation of ability to detect and identify common odors in humans psychophysically. Olfactory tests are currently administered by professionals with a set of given odorants. Manual administration of such tests can be labor and cost intensive and data collected as such are confounded with experimental variables, which adds personnel costs and introduces potential errors and data variability. For large-scale and longitudinal studies, manually recorded data must be collected and compiled from multiple sites. It is difficult to standardize the way data are collected and recorded. There is a need for a computerized smell test system for psychophysical and clinical applications. A mobile digital olfactory testing system (DOTS) was developed, consisting of an odor delivery system (DOTS-ODD) and a mobile application program (DOTS-APP) connected wirelessly. The University of Pennsylvania Smell Identification Test was implemented in DOTS and compared to its commercial product on a cohort of 80 normosmic subjects and a clinical cohort of 12 Parkinson's disease patients. A test-retest was conducted on 29 subjects of the normal cohort. The smell identification scores obtained from the DOTS and standard UPSIT commercial test are highly correlated (r = 0.714, P < 0.001), and test-retest reliability coefficient was 0.807 (r = 0.807, P < 0.001). The DOTS is customizable and mobile compatible, which allows for the implementation of standardized olfactory tests and the customization of investigators' experimental paradigms. The DOTS-APP on mobile devices offers capabilities for a broad range of on-site, online, or remote clinical and scientific chemosensory applications.

International consensus statement on allergy and rhinology: Olfaction

BACKGROUND

The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O).

METHODS

Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus.

RESULTS

The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies.

CONCLUSION

This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.

“Anosmia” the mysterious collateral damage of COVID-19

COVID-19 pandemic spreads worldwide, with more than 100 million positive cases and more than 2 million deaths. From the beginning of the COVID-19 pandemic, several otolaryngologists described many cases of a sudden loss of smell (anosmia) associated with the disease with or without additional symptoms. Anosmia is often the first and sometimes the only sign in the asymptomatic carriers of COVID-19. Still, this disorder is underestimated, and it is not life-threatening. However, it significantly decreases the quality of life. This olfactory dysfunction continues in several cases even after the nasopharyngeal swab was negative. The occurrence of anosmia can be used as a screening tool for COVID-19 patients and can be used to identify these patients to accomplish the isolation and tracking procedures. In this review, we highlighted the possible mechanisms of anosmia in COVID-19 patients, major pathologies and features of anosmia, implications of anosmia in early diagnosis of COVID-19, evaluation of the smell function during COVID-19, and management and treatment options of COVID-19 anosmia.

The digital scent device as a new concept for olfactory assessment

BACKGROUND

There are major challenges in olfactory measurements in clinical practice; therefore, a handheld digital scent device (DSD; Noar MultiScent 20) was developed as a tablet with an integrated storage system for odors. The DSD is a self-administered, handheld device that controls the duration of odor release to the nasal cavity through a touchscreen digital interface with automatic database generation. In this study we aimed to determine the feasibility of this DSD as an olfactory assessment test.

METHODS

We recruited 180 participants (age [mean ± standard deviation], 34.58 ± 9.71 years; 114 women and 66 men) to participate in smell tests using both the DSD and the 40-item Smell Identification Test (SIT-40), which contained the same type and order of odors and the same multiple-choice answers. The scores were compared and evaluated for correlation between the tests, and test-retest reliability was calculated.

RESULTS

The DSD test scores were higher than the SIT-40 scores (median [interquartile range], 32 [5.0] vs 31 [7.0]; p = 0.005). The completion time was less for the DSD test than for the SIT-40 (12.5 [5.0] vs 16 [6.0] minutes; p < 0.001). The tests were strongly correlated (Spearman rho = 0.74; p < 0.001) and exhibited a high level of agreement (Bland-Altman regression coefficient = 0.672; p = 0.003). The DSD test-retest reliability coefficient was 0.820.

CONCLUSION

The DSD is feasible as an olfactory assessment test. The digitalization of olfactory assessment combined with data science may enable new research perspectives in the field of olfaction.

Clinical assessment of olfactory function

Approximately 5% of the general population is affected by functional anosmia with approximately additional 15% exhibiting decreased olfactory function. Many of these individuals ask for help. Because the subjective rating of olfactory function is biased, assessment of olfactory function is important. Olfactory measurements are needed for patient counseling and the tracking of changes in the sense of smell over time. The present review provides an overview of frequently used psychophysical tests for olfactory function, discusses differences between threshold and suprathreshold aspects of olfactory function, and gives examples on how to apply psychophysical tests.

Clinical validation of the olfactory detection threshold module of the Snap & Sniff® olfactory test system

BACKGROUND

Quantitative olfactory testing is essential to determine the validity and nature of a patient's complaint, accurately monitor changes in function over time (including influences of pharmacological, surgical, or immunological interventions), detect malingering, and establish disability compensation. This work describes the clinical validation of an advanced rapid odor detection threshold test that standardizes odorant delivery and eliminates unsanitary sniff bottles, the need for blindfolds, and the possibility of touching an odorant stimulus to the nose.

METHODS

Snap & Sniff® single-staircase phenyl ethyl alcohol detection thresholds (S&S-Ts) were assessed bilaterally in 736 patients with chemosensory complaints; 421 received both bilateral and unilateral testing. The results were correlated with scores from the University of Pennsylvania Smell Identification Test (UPSIT) and the Smell Threshold Test (STT), a widely-used standardized threshold test. Test-retest reliability data were obtained for 50 patients.

RESULTS

S&S-Ts were highly reliable (Spearman r = 0.84), correlated with the other olfactory test measures (rs > 0.65, ps < 0.0001), and required significantly shorter administration times than the STT (<10 minutes). Bilateral thresholds were systematically lower than unilateral thresholds, a phenomenon independent of presentation order but dependent upon the better functioning side of the nose. The S&S-Ts were sensitive to age and sex. No systematic left:right nasal side threshold differences were evident.

CONCLUSION

The present study validates the use of Snap & Sniff® technology in the clinic setting. High test-retest reliability and brief administration times were evident. The S&S-T test allows for a reliable, valid, inexpensive, and rapid clinical means for quantitatively assessing human olfactory sensitivity.

Neuroimaging of smell and taste

The senses of taste and smell developed early in evolution and are of high ecological and clinical relevance in humans. Chemosensory systems function, in large part, as hazard avoidance systems, thereby ensuring survival. Moreover, they play a critical role in nutrition and in determining the flavor of foods and beverages. Their dysfunction has been shown to be a key element of early stages of a number of diseases, including Alzheimer's and Parkinson's diseases. Advanced neuroimaging methods provide a unique means for understanding, in vivo, neural and psychological processing of smell, taste, and flavor, and how diseases can impact such processing. This chapter provides, from a neuroimaging perspective, a comprehensive overview of the anatomy and physiology involved in the odor and taste processing in the central nervous system. Some methodological challenges associated with chemosensory neuroimaging research are discussed. Multisensory integration, the mechanisms that enable holistic sensory experiences, is emphasized.

Standard-dose versus low-dose multidetector computed tomography examinations in patients with uncontrolled chronic rhinosinusitis: A randomized, controlled trial

BACKGROUND

Multidetector computed tomography (MDCT) images for rhinosinusitis may have a risk of radiation hazards. Reduction in radiation dose may lead to a compromise in quality of MDCT images and have chances of postoperative complications.

OBJECTIVE

The aim of the study was to test the applicability of low-dose MDCT protocols for decision-making of sinus surgeries of patients with uncontrolled chronic rhinosinusitis.

DESIGN

Randomized, double-blind (patients and evaluators blind), controlled, trial.

SETTING

People's Hospital of Guanghan, China.

PATIENTS

A total of 288 patients with clinically confirmed uncontrolled chronic rhinosinusitis were subjected to randomization (1:1 ratio).

INTERVENTIONS

Patients were subjected to low-dose preoperative protocols of MDCT (n = 144; ldMDCT group) or standard-dose preoperative protocols of MDCT (n = 144; sdMDCT group).

OUTCOME MEASURES

Image analysis was performed by the workstation. Lund-Mackay score, modified Lund-Mackay score, estimated radiation exposure, and surgical complications were evaluated for each patient. The χ independent test or 2-tailed paired t test were performed for statistical analysis.

RESULTS

The preoperative MDCT images for standard-dose protocol had better quality than low-dose protocol (P < .001, q = 4.57). The area of images that give confidence for sinus surgery at one time was higher for standard-dose MDCT protocol technique than low-dose MDCT protocol method. Patients of ldMDCT group with large growth of nasal polyps (P = .03, q = 5.35) and complete opacification of sinuses (P = .03, q = 7.94) had complications after sinus surgeries. Either low-dose or standard-dose MDCT protocol was performed, the experience of otolaryngologist had decreased complication after surgeries.

CONCLUSION

Preoperative low-dose MDCT should be used for diagnosis of uncontrolled chronic rhinosinusitis for decision making of sinus surgeries.

LEVEL OF EVIDENCE

III.

TRIAL REGISTRATION

researchregistry4264 dated 1 March 2016 (www.researchregistry.com).

A Pilot Study of the Snap & Sniff Threshold Test

OBJECTIVES

The Snap & Sniff^® Threshold Test (S&S) has been recently developed to determine the olfactory threshold. The aim of this study was to further evaluate the validity and test-retest reliability of the S&S.

METHODS

The olfactory thresholds of 120 participants were determined using both the Smell Threshold Test (STT) and the S&S. The participants included 30 normosmic volunteers and 90 patients (60 hyposmic, 30 anosmic). The normosmic participants were retested using the STT and S&S at an intertest interval of at least 1 day.

RESULTS

The mean olfactory threshold determined with the S&S was -6.76 for the normosmic participants, -3.79 for the hyposmic patients, and -2 for the anosmic patients. The olfactory thresholds were significantly different across the 3 groups ( P < .001). Snap & Sniff-based and STT-based olfactory thresholds were correlated weakly in the normosmic group (correlation coefficient = 0.162, P = .391) but more strongly correlated in the patient groups (hyposmic: correlation coefficient = 0.376, P = .003; anosmic: correlation coefficient = 1.0). The test-retest correlation for the S&S-based olfactory thresholds was 0.384 ( P = .036).

CONCLUSION

Based on validity and test-retest reliability, we concluded that the S&S is a proper test for olfactory thresholds.