A comparison of the sniff magnitude test and the University of Pennsylvania Smell Identification Test in children and nonnative English speakers

The sniff magnitude test (SMT) is a reliable and rapid clinical test of olfactory function that is minimally dependent on cognitive and linguistic abilities. In this study, we compared performance on the SMT and University of Pennsylvania Smell Identification Test (UPSIT) in samples of children and nonnative English speakers. Previous research has shown that these populations perform poorly on the UPSIT as compared with young, healthy U.S. adults. Such performance differences may reflect variations in memory/cognition and language/culture rather than olfactory abilities. The UPSIT scores of children and of Indian and Chinese graduate students were found to be lower than those of young U.S. adults. By contrast, these groups did not perform more poorly than U.S. adults did on the SMT. The results are consistent with findings from our studies, with the elderly showing that performance on the UPSIT, but not the SMT, is significantly correlated with measures of memory, language and other cognitive abilities. The findings highlight the utility of the SMT when evaluating the olfactory ability of the very young, older adults and people with diverse linguistic and cultural backgrounds.     

Application of multidimensional scaling to ratings of foods for obese and normal weight individuals

Sixteen obese patients, aged 19–31, and 27 normal weight individuals, aged 18–22, tasted and smelled fresh, unseasoned blended foods while blindfolded. Then they rated the foods on 51 semantic differential adjective scales which related to stimulation of the gustatory, olfactory, and trigeminal systems. The stimuli included fruits, vegetables, meat, fish, nuts, dairy products, grains, and a set of four standards: sucrose (sweet), NaCl (salty), lemon (sour), and coffee (bitter) in a thin cornstarch base. Proximity measures among stimuli for each subject were developed from the ratings on the adjective scales. Two multidimensional scaling (MDS) procedures, SINDSCAL (a variation of INDSCAL) and ALSCAL, were applied to the proximity measures yielding two-dimensional food maps which were very similar. Both MDS procedures provided weights for each subject on the two dimensions of the space common for all subjects. The weights indicated that the obese subjects found the first dimension, which was related to the hedonic and flavorous aspects of the stimuli, relatively more important than normal weight individuals. Also, obese subjects were significantly better at identifying the blended foods when compared to normal weight subjects.     

Mechanism of olfactory deficit in neurotrauma and its related affective distress: A narrative review

Traumatic brain injury (TBI) is among the leading causes of death and disability all over the globe. TBI is also commonly associated with clinical sequelae of posttraumatic depression, and reports of other subsequent affective distress are common. Similarly, posttraumatic changes in chemoreceptive sensory functions, primarily due to coup-contrecoup injury induced shearing of the olfactory nerve fibers, leading to anosmia and ageusia are also well documented in the literature. However, the current literature is limited in addressing the intersections between said variables. The aim of this study was to provide a focused narrative review of the literature, to address these intersections found in clinical sequelae of TBI. As chemoreceptive sensory deficits are also linked to significant affective distress of their own, this review addresses the bidirectionality between sensory deficit and affective distress. Prevalence, demographics, mechanisms, and clinical implications are presented. Previous research is presented and discussed, in an effort to highlight the importance of consideration for all factors in TBI patient care and future research.     

CORRELATIONS AMONG BEHAVIORAL MEASURES OF ORBITOFRONTAL FUNCTION

Orbitofrontal cortex plays an important role in guiding behavior based on emotional input and rewards. It receives multimodal higher order sensory information and mediates reinforcement for primary as well as secondary or conditioned forms of reinforcement (e.g., monetary rewards). Several behavioral measures have demonstrated putative sensitivity to orbitofrontal function: smell identification, delayed alternation, and response inhibition (go/no-go and antisaccades). A correlational study of performances on these tasks by healthy controls demonstrated some interrelationships: go/no-go correlated with antisaccades, left nostril smell correlated with go/no-go, and right nostril smell correlated with delayed alternation. Further analysis showed that certain smells correlated with tasks more strongly than others. Given the diversity of these tasks, it is suggested that these intercorrelations result from at least the partial overlap of the neural substrates for olfactory identification and tasks requiring response modification based on reinforcement contingencies.     

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

IntroductionAssessing 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.ObjectivesTo 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.MethodsFifty 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.ResultsBoth 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.ConclusionsThe 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.     

Olfactory performance in spinocerebellar ataxia type 7 patients

A large body of evidence has shown olfactory deficits in many neurodegenerative diseases. However, the nature of the olfactory impairment remains poorly understood partly because the majority of studies have only explored smell identification capabilities. The purpose of the present study was twofold. First we wanted to test if patients with spinocerebellar ataxia type 7 (SCA7), a progressive neurodegenerative disorder characterized by cerebellar ataxia and visual loss, also have olfactory deficits. Secondly, we wanted to test the nature of the olfactory deficits by testing not only the identification level but also olfactory threshold and discrimination. Based on the olfactory dysfunction found in different neurodegenerative diseases and functional neuroimaging data showing cerebellar activation during olfaction, we hypothesized that SCA7 patients would show an olfactory impairment. To test this hypothesis we studied twenty-eight genetically confirmed SCA7 patients and twenty-seven matched controls using the Sniffing Sticks Test and the University of Pennsylvania Smell Identification Test (UPSIT). The results show that SCA7 patients' ability to discriminate and identify odors is significantly impaired, although their odor detection thresholds were at normal levels. These results suggest that SCA7 neurological damage affects olfactory perception but spares the patients' olfactory sensory capabilities.     

Regional and Chronological Variation of Chemosensory Dysfunction in COVID-19: a Meta-Analysis

BackgroundOlfactory and gustatory dysfunction are frequently reported in patients with coronavirus disease 2019 (COVID-19). However, the reported prevalence of olfactory and/or gustatory dysfunction varies widely, and the reason for the inter-study differences is unclear. Hence, in this meta-analysis, we performed subgroup analyses to investigate the factors that contribute to the inter-study variability in the prevalence of olfactory and gustatory dysfunction.MethodsOut of 943 citations, we included 55 eligible studies with 13,527 patients with COVID-19 for a meta-analysis. Calculating the data extracted from each study, the weighted summary prevalence of olfactory and gustatory dysfunction was estimated using a Freeman-Tukey transformation with models based on random-effects assumptions. A meta-analysis of variance compared the prevalence of olfactory and gustatory dysfunction according to regional, chronological, demographic, and methodologic factors, respectively.ResultsThe overall pooled prevalence rates of olfactory and gustatory dysfunction were 51.4% and 47.5%, respectively, in the random-effect model. In subgroup analyses, the prevalence rates of olfactory and gustatory dysfunction were significantly different among four geographical regions (both P < 0.001, respectively). Although the prevalence rates of olfactory and gustatory dysfunction did not significantly differ according to the time of enrollment, the subgroup analyses including only studies from the same geographical region (Europe) revealed a significant difference in olfactory dysfunction according to the time of enrollment.ConclusionThe regional and chronological differences in the prevalence rates of olfactory and gustatory dysfunctions partly explain the wide inter-study variability.     

Assessment the long-term effects of septoplasty surgery on olfactory function

Objectives: This research aimed to evaluate pre-operatively and post-operatively the olfactory function of patients who had undergone surgery in our clinic for chronic nasal blockage via the Connecticut Chemosensory Clinical Research Center (CCCRC) smell test.

Method: Thirty-seven patients (24 females, 13 males) were enrolled in this study. All had undergone surgery in our clinic due to chronic nasal blockage (not for smell dysfunction), having been diagnosed with septal deviation in conjunction with concha bullosa and/or inferior turbinate hypertrophy. This is a prospective study without a control group. The mean age was 33.74?±?8.98 (range =19–54). All of the operations were performed under general anesthesia. CCCRC smell tests were performed on every patient before the operation and at post-operative 1st week, 6th week, 6th month, and 1st year.

Results: In this study, we found that septoplasty, in conjunction with middle concha surgery and/or inferior concha radiofrequency, did not affect the olfactory function negatively.

Conclusion: Although nasal surgery has the potential to affect the smell function negatively, it was found that olfactory function was not affected after the surgery during a considerably long follow-up period. Moreover, an improvement in smell function was detected at post-operative 6th month and 1st year.