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.     

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.     

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.     

Adaptation of the Sniffin’ Sticks Test in South-Kivu

AimThe “Sniffin’ Sticks” test is widely used in Europe as a standard test to assess olfaction. Several culturally-adapted versions have been developed. However, no version adapted to Sub-Saharan African populations exists. The aims of the present study were (1) to assess the applicability of the Sniffin’ Sticks test in the population of South Kivu (DR Congo), and (2) to develop a culturally adapted version with normative values.Materials and methodsIn a first study, 157 volunteers were tested with the original Sniffin’ Sticks test. Based on these results, we selected odors that were poorly recognized in the identification test and replaced them by culturally adapted odors. In a second study, we assessed the modified version of the Sniffin’ Sticks test in 150 volunteers and defined normative values.ResultsIn the first study, we found that olfactory function (threshold-discrimination-identification: TDI score) significantly decreased with age and was better in females. Five odors were poorly recognized and were replaced by culturally adapted odors. In the second study, we found that this adapted version led to a higher rate of correctly identified odors. We defined normative values for the South-Kivu population (TDI score: 18–35 years: 30.4 ± 6.0; 36–55 years: 26.2 ± 5.3; > 55 years: 25.6 ± 5.0).ConclusionThis culturally adapted version of the Sniffin’ Sticks test is culturally adapted to the South Kivu population. The normative values will provide the basis for clinical evaluation of pathologic subjects.     

乙醇气味刺激食蟹猴的脑fMRI

目的 应用3.0T fMRI探讨食蟹猴经乙醇气味刺激引起的脑功能活动。方法 选取健康食蟹猴6只,麻醉后行乙醇气味刺激下的fMRI。采取"静息-刺激-静息"组块设计。刺激组块予乙醇气味刺激,静息组块无气味刺激。BOLD-fMRI扫描128 phase,整个猴脑扫描16层。采用SPM2软件随机效应模式t检验进行组分析。将统计结果覆盖于食蟹猴模板图像上。结果 乙醇气味刺激下,在额叶、颞叶、中央旁小叶、扣带回、豆状核、中央前回分别可以检测到正激活和负激活。结论 海马回钩和眶额回为嗅觉最高级中枢。fMRI可以显示额叶、颞叶的激活。气味刺激引起的中枢反应与中央旁小叶、扣带回、豆状核有密切关系。     

鼻咽癌患者放疗后嗅觉功能及嗅球体积和嗅沟深度的研究

目的探讨放疗对鼻咽癌患者嗅觉功能以及嗅球体积和嗅沟深度的影响。方法选取鼻咽癌放疗结束后1年以上的患者(测试组)及无嗅觉减退的健康受试者(对照组)各20例,采用TT嗅觉测试法检查所有受试者的嗅觉功能,并行嗅球体积、嗅沟深度MRI检查。结果测试组TT嗅觉测试法嗅觉功能评分大于对照组,测试组平均嗅球体积明显小于对照组。测试组与对照组平均嗅沟深度比较无差异。测试组嗅觉识别阈与嗅球体积呈负相关性(r=-0.641,P<0.05),与嗅沟深度无关(r=-0.175,P>0.05)。结论鼻咽癌放疗后嗅觉减退患者,嗅球体积减少,嗅沟深度不变;嗅觉功能与嗅球体积具有相关性,与嗅沟深度无关。     

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.     

A RELATIONSHIP BETWEEN SMELL IDENTIFICATION AND EMPATHY

Olfaction is a sense that has close relationships with the limbic system and emotion. Empathy is a vicarious feeling of others emotional states. The two functions are known to be subserved by common neuroanatomical structures, including orbitofrontal cortex, mediodorsal thalamus, and the amygdala. This study demonstrates a correlation between smell identification and empathy, using the Mehrabian and Epstein Empathy Questionnaire and Alberta Smell Test. Right nostril smell identification correlated with empathy, whereas the left nostril did not. Given the predominantly ipsilateral representation in the olfactory system, this is in accordance with right hemisphere dominance for emotional functions and empathy. Further, the emotional component of empathy (feeling another s emotions) correlated with smell, whereas a cognitive component (comprehending another s emotions) did not. This study is the first to demonstrate a relationship between empathy and smell in normal subjects, suggesting common neural substrates.