Odor Stick Identification Test Research Articles

Correlation Between Cortical Thickness Abnormalities of the Olfactory Sulcus and Olfactory Identification Disorder and Persistent Auditory Verbal Hallucinations in Chinese Patients With Chronic Schizophrenia.

Persistent auditory verbal hallucinations (pAVHs) and olfactory identification impairment are common in schizophrenia (SCZ), but the neuroimaging mechanisms underlying both pAVHs and olfactory identification impairment are unclear. This study aimed to investigate whether pAVHs and olfactory identification impairment in SCZ patients are associated with changes in cortical thickness. In this study, cortical thickness was investigated in 78 SCZ patients with pAVHs (pAVH group), 58 SCZ patients without AVHs (non-AVH group), and 83 healthy controls (HC group) using 3T magnetic resonance imaging. The severity of pAVHs was assessed by the Auditory Hallucination Rating Scale. Olfactory identification deficits were assessed using the Odor Stick Identification Test for Japanese (OSIT-J). In addition, the relationship between the severity of pAVHs and olfactory identification disorder and cortical thickness abnormalities was determined. Significant reductions in cortical thickness were observed in the right medial orbital sulcus (olfactory sulcus) and right orbital sulcus (H-shaped sulcus) in the pAVH group compared to both the non-AVH and HC groups (P < .003, Bonferroni correction). Furthermore, the severity of pAVHs was found to be negatively correlated with the reduction in cortical thickness in the olfactory sulcus and H-shaped sulcus. Additionally, a decrease in cortical thickness in the olfactory sulcus showed a positive correlation with the OSIT-J scores (P < .05, false discovery rate correction). Cortical thickness abnormalities in the olfactory sulcus may be a common neuroimaging mechanism for pAVHs and olfactory identification deficits in SCZ patients.

Risk stratification for phenoconversion in patients with isolated REM sleep behavior disorder. A follow-up study from Turkey.

Isolated rapid eye movement (REM) sleep behavior disorder (iRBD) is one of the strongest prodromal markers of alpha-synucleinopathies. We aimed to investigate non-invasive clinical and quantitative predictors of phenoconversion from iRBD to parkinsonism. We prospectively followed-up a total of 45 patients (57.8% men) for eight years. Clinical assessments, Sniffin' Sticks Odor Identification Test, Farnsworth-Munsell 100 Hue Color Vision test, Beck Depression Inventory and Rome III Criteria for constipation were performed. Polysomnographic parameters, sleep spindles, electroencephalographic (EEG) spectral analysis, heart rate variability (HRV) were analyzed. Eight patients (17.8%) showed phenoconversion to parkinsonism after a mean duration of 3.2 ± 1 years. Odds ratio for predicting phenoconversion was highest for patients =60 years of age with anosmia and constipation -44.8 (4.5-445.7); kappa = 4.291-. Duration, frequency or density of sleep spindles failed to demonstrate significant correlations. In EEG spectral analysis, lower alpha power in occipital region during wakefulness and REM sleep was significantly correlated with phenoconversion. Slowing in EEG spectrum power, together with age =60 years, anosmia and constipation, resulted in the highest odds ratio -122.5 (9.7-1543.8); kappa = 3.051-. It is of great importance to have a world-wide perspective of phenoconversion rates from iRBD to overt neurodegeneration, since racial and geographical factors may play important modifying roles. Relatively younger age and shorter disease duration may also be confounding factors for lower rate in our study. Neurophysiological biomarkers seem to be important predictors of phenoconversion, though more research is needed to establish subtypes of iRBD with different probabilities of evolution to overt synucleinopathy.

Factors influencing olfactory function in an adult general population sample: the CHRIS study.

The sense of smell allows for the assessment of the chemical composition of volatiles in our environment. Different factors are associated with reduced olfactory function, including age, sex, as well as health and lifestyle conditions. However, most studies that aimed at identifying the variables that drive olfactory function in the population suffered from methodological weaknesses in study designs and participant selection, such as the inclusion of convenience sample or only of certain age groups, or recruitment biases. We aimed to overcome these issues by investigating the Cooperative Health Research in South Tyrol (CHRIS) cohort, a population-based cohort, by using a validated odor identification test. Specifically, we hypothesized that a series of medical, demographic and lifestyle variables is associated with odor identification abilities. In addition, our goal was to provide clinicians and researchers with normative values for the Sniffin' Sticks identification set, after exclusion of individuals with impaired nasal patency. We included 6,944 participants without acute nasal obstruction and assessed several biological, social, and medical parameters. A basic model determined that age, sex, years of education, and smoking status together explained roughly 13% of the total variance in the data. We further observed that variables related to medical (positive screening for cognitive impairment and for Parkinson's disease, history of skull fracture, stage 2 hypertension) and lifestyle (alcohol abstinence) conditions had a negative effect on odor identification scores. Finally, we provide clinicians with normative values for both versions of the Sniffin' Sticks odor identification test, i.e. with 16 items and with 12 items.

42 Cognitive and Neuroanatomic Correlates of Olfactory Function in Cognitively Unimpaired and Impaired Older Adults

Objective:Olfactory function declines during normal aging; however, accelerated olfactory decline is observed in neurodegenerative diseases, such as Alzheimer’s disease (AD). Moreover, olfactory deficits in pre-clinical AD are associated with future cognitive decline. Odor identification and memory deficits have been consistently reported in early stage AD indicating its potential sensitivity to AD pathophysiology in olfactory and limbic structures, yet few studies of olfaction have incorporated structural measures in a well-characterized cohort of older adults. In the current study we examined the association between odor identification impairment, cognition, and medial temporal lobe (MTL) sub-regions in cognitively unimpaired and impaired older adults.Participants and Methods:We enrolled 140 participants (age=72.25±6.54, 56% female, years of education=16.30±2.63, 82% Caucasian, 15% Black/AA, 3% Multiracial) from the Penn Alzheimer’s Disease Research Center Clinical Cohort. Participants completed the Sniffin’ Sticks Odor Identification Test (SS-OIT), cognitive testing (NACC UDS2 or UDS3 and additional cognitive tests), and MRI scans (3T Siemens MAGNETOM Prisma MRI scanner). For the SS-OIT, participants were presented with 16 odorants using felt-tipped pen dispensers and asked to identify each odor from four multiple-choice options. Scores range from 0 to 16. Additionally, cognitive domains were created by averaging z-scores from tests within each domain: attention, memory, language, executive function, and visuospatial. This cohort was divided into participants with unimpaired cognition (n=96) and impaired cognition (MCI, dementia; n=44) using established normative data and consensus diagnosis. Linear regressions were performed to examine the association between SS-OIT score, each cognitive domain, and MTL measurements for unimpaired and impaired groups. For all analyses, we controlled for age, race, sex, education, smoking status, and hypertension and additionally for MOCA score and intracranial volume with MTL measurements.Results:In the unimpaired group, SS-OIT significantly associated with language (p&lt;.05). In the impaired group, SS-OIT significantly associated with language and memory (p&lt;.05). In the unimpaired group, SS-OIT significantly associated with right anterior hippocampal volume (p&lt;.05). In the impaired group, significant associations were found between SS-OIT and right anterior hippocampal volume (p&lt;.05) and left hippocampal mean thickness (p&lt;.05). Additionally, SS-OIT significantly associated with left and right entorhinal cortex volume (p&lt;.05) and mean thickness (p&lt;.05).Conclusions:This study reveals that lower odor identification performance is related to lower performance on measures of cognition and atrophy in MTL sub-regions in unimpaired and impaired older adults. Our findings support prior results demonstrating relationships between olfactory function, cognition, and MTL sub-regions. Specifically, olfactory function and episodic memory have been shown to follow similar patterns of decline in the course of AD, potentially reflecting AD pathology in shared regions of the MTL subserving episodic memory and olfactory function. Our findings demonstrate that reductions in both cortical thickness and grey matter volume of MTL regions are linked to olfactory deficits in individuals at risk for Alzheimer’s dementia. Future steps will include the analysis of longitudinal cognitive and imaging indices and the incorporation of fluid biomarker data.

Normative Data for the 12-Item Sniffin' Sticks Odor Identification Test in Older Adults.

Quantitative olfactory assessment has demonstrated clinical utility for the evaluation of a range of neurologic, psychiatric, and sinonasal conditions. Here, we provide age, sex, race, and education-specific normative data for the 12-item Sniffin Sticks Odor Identification Test (SSOIT-12) in older Black and White U.S. adults without preclinical or clinical dementia or sinonasal disease. A sample of 2,224 Atherosclerosis Risk in Communities study participants aged 66-89years were included. A normative regression equation was developed using a linear model for the association of age, sex, race, and education with odor identification score. Regression-based normative mean scores and percentiles were generated by age, sex, race, and education groups. Participants (mean age = 74years, 59% women, 20% Black, 48% > high school education) had a mean SSOIT-12 score of 9.8. Age, sex, race, and education were all associated with odor identification performance (all ps < .05). A linear regression model for the predicted SSOIT-12 score was developed for use with an individual's actual SSOIT-12 score in order to calculate the Z-score and corresponding percentile for a specific age, sex, race, and education group. Data are also reported in tabular format. Our study provides SSOIT-12 normative data obtained from a large population of White and Black older adults without preclinical or clinical dementia or sinonasal disease living in the USA. These findings can aid clinicians in assessing the degree of olfactory loss, establishing concordance with a person's perception of olfactory difficulties and quantitatively monitoring changes in olfactory performance over time.

A - 11 Cognitive and Clinical Correlates of Olfactory Function in Adults with Epilepsy.

Olfactory dysfunction is well-documented in epilepsy. We recently found that olfactory assessment may have clinical utility in identifying surgical candidates with intractable epilepsy who benefit from magnetic resonance-guided laser interstitial thermal therapy (MRgLiTT). However, the demographic, clinical, and cognitive correlates of olfaction in epilepsy remain unclear and could aid in understanding its potential utility in clinical examinations. We identified 60 outpatients with epilepsy (mean age = 38.22 ± 13.84years; 50% male; 89.3% right-handed; seizure location: 45.0% left, 33.3% right, 13.3% bilateral, 8.3% unspecified) referred for neuropsychological evaluation in the Johns Hopkins Division of Medical Psychology Clinic. Neuropsychological evaluation included the 16-item Sniffin' Sticks Odor Identification Test. Linear regression models were used to examine associations between 1) olfaction and demographic/clinical characteristics (age, sex, education, duration of illness, seizure laterality) and 2) olfaction and cognition (processing speed, language, auditory-verbal and visuospatial memory, executive functioning; adjusted for demographic/clinical characteristics). Olfactory performance was not significantly associated with demographic or clinical characteristics. Across all participants, better olfactory performance was associated with better auditory-verbal memory (B = 5.04, t(46) = 4.16, p < 0.001) and visual confrontation naming (B = 1.53, t(45) = 4.11, p < 0.001) with correction for multiple comparisons. In a subset with lateralizing epilepsy (n = 47), better odor identification performance remained a significant predictor of the aforementioned cognitive measures with adjustment for demographic and clinical characteristics. Consistent with work in other neurologic conditions, our preliminary findings indicate that olfactory function is associated with verbally-mediated neuropsychological measures in epilepsy. Future studies utilizing pre-surgical neuroimaging will examine the association between olfaction, cognition, and radiographic markers of tissue integrity in epilepsy.

"Mmm, Smells like Coffee!": How a Brief Odor Identification Test Could Help to Identify People with Mild Cognitive Impairment and Dementia.

(1) Background: Dementia and mild cognitive impairment (MCI) are still underdiagnosed in the general population. Impaired odor identification has been identified as an early marker of MCI and dementia. We aimed to compare the additional diagnostic value of two odor identification tests to a cognitive screening test in detecting MCI or dementia. (2) Methods: The Sniffin' Sticks odor identification test (SS-OIT), a brief odor identification test (B-OIT) requiring the identification of coffee scent, and the Mini-Mental State Exam (MMSE) were administered to a consecutive series of 174 patients (93 with dementia, 42 with mild cognitive impairment, and 39 without cognitive impairment) referred for neuropsychological testing. (3) Results: Both participants with dementia and with MCI exhibited impairments in odor identification. The SS-OIT and the B-OIT were substantially correlated. Complementing MMSE scores with the SS-OIT or the B-OIT similarly improved the diagnostic accuracy of individuals with dementia and MCI. (4) Conclusions: People with suspected dementia or MCI may already benefit from brief odor identification tests. Although these tests require little additional time, they can notably increase sensitivity for dementia or MCI.

Treatment of COVID-19 olfactory dysfunction with olfactory training, palmitoylethanolamide with luteolin, or combined therapy: a blinded controlled multicenter randomized trial

PurposeFew evidence-based therapies are available for chronic olfactory dysfunction after COVID-19. This study investigated the relative efficacy of olfactory training alone, co-ultramicronized palmitoylethanolamide with luteolin (um-PEA–LUT, an anti-neuroinflammatory supplement) alone, or combined therapy for treating chronic olfactory dysfunction from COVID-19.MethodsThis double-blinded controlled, placebo-controlled multicenter randomized clinical trial was conducted in 202 patients with persistent COVID-19 olfactory dysfunction of > 6 month duration. After a screening nasal endoscopy, patients were randomized to: (1) olfactory training and placebo; (2) once daily um-PEA–LUT alone; (3) twice daily um-PEA–LUT alone; or (4) combination of once daily um-PEA–LUT with olfactory training. Olfactory testing (Sniffin’ Sticks odor identification test) was performed at baseline and at 1, 2, and 3 months. The primary outcome was recovery of over three points on olfactory testing, with outcomes compared at T0, T1, T2 and T3 across groups. Statistical analyses included one-way ANOVA for numeric data and chi-square for nominal data.ResultsAll patients completed the study, and there were no adverse events. At 90 days, odor identification scores improved by > 3 points in 89.2% of patients receiving combined therapy vs. 36.8% receiving olfactory training with placebo, 40% receiving twice daily um-PEA–LUT alone, and 41.6% receiving once daily um-PEA–LUT alone (p < 0.00001). Patients receiving treatment with um-PEA–LUT alone demonstrated subclinical improvement (< 3 point odor identification improvement) more often than patients receiving olfactory training with placebo (p < 0.0001.)ConclusionsOlfactory training plus once daily um-PEA–LUT resulted in greater olfactory recovery than either therapy alone in patients with long-term olfactory function due to COVID-19.Trial registration20112020PGFN on clinicaltrials.gov.Level of evidence1b (Individual Randomized Clinical Trial).

Identifying the potential role of serum miR-20a as a biomarker for olfactory dysfunction in patients with Parkinson's disease.

Olfactory dysfunction (OD), one of the most common non-motor symptoms in Parkinson's disease (PD), is a cardinal prodromal symptom that can appear years before the onset of motor symptoms. Ongoing studies have demonstrated that microRNAs (miRNAs) are suitable biomarkers for PD, while there is a lack of robust miRNAs that can serve as markers for OD in PD. The concordantly differentially expressed miRNAs (DE miRNAs) in the damaged olfactory system were first identified in 2 OD-related Gene Expression Omnibus (GEO) datasets. Then, they were verified in another PD-related GEO dataset and only one miRNA (miR-20a) was found to be significantly altered. Serum levels of miR-20a were further measured by qPCR in 79 PD patients with OD (PD-OD), 52 PD patients without OD (PD-NOD), and 52 healthy controls (HC). Objective measure of OD was defined by 16-item Sniffin' Sticks odor identification test. All the participants underwent a demographic and comprehensive PD-related clinical assessment. Our results proved that miR-20a was significantly downregulated in PD-OD compared with PD-NOD and the area under curve (AUC) for OD detection by miR-20a was 0.803 (95% confidence interval, 0.724-0.883). In addition, PD-OD had higher scores of Movement Disorder Society-Unified Parkinson's Disease Rating Scale (UPDRS) II, Hoehn and Yahr stage (H-Y), Non-Motor Symptoms Scale (NMSS) 3, NMSS 5, NMSS 9, Hamilton Rating Scale for Depression (HAMD), Hamilton Anxiety Scale (HAMA), Activity of Daily Living (ADL), and lower scores of Mini-Mental State Examination (MMSE) and 39-item PD Quality of Life Questionnaire (PDQ-39) than PD-NOD. Binary regression model further presented that lower expressions of miR-20a and poorer cognitive function acted as promoting factors in the development of OD. Our results suggest that miR-20a could be a novel biomarker for OD in PD and PD-OD patients tend to have higher disease stage, poorer motor aspects of experiences of daily living, worse cognitive scores, and inferior quality of life, and were more likely to have mental disorders. Cognitive function, in particular, is strongly associated with OD in PD patients.

Correction to Leonhardt et al. (2019).

A sample of 124 nondemented PD patients and 154 elderly controls was assessed with the Sniffin' Sticks Odor Identification Test (OIT) and the Subjective Olfactory Capability (SOC) domain of the Assessment of Self-Reported Olfactory Functioning and Olfaction-Related Quality of Life, additional to measures of depressive symptoms, verbal memory and executive functioning. Olfactory awareness groups were formed by means of the cut-offs of the OIT and the SOC. Significant correlations between the OIT and the SOC were moderate in participants with PD and small in controls. Of all PD patients, 52% overrated their sense of smell while 27% correctly identified themselves as being hyposmic, as opposed to corresponding 6% and 1% of healthy elderly. Overrating and aware of being hyposmic participants with PD showed worse executive functions than PD patients who were objectively and subjectively normosmic. The findings imply that, although people with PD are aware of hyposmia to some extent, the majority is affected by overestimation of the ability to smell, making self-reported functioning an unreliable source of information. Moreover, reduced odor identification and impaired executive functioning might underlie the same pathological changes within the brain and could serve as a marker for cognitive impairment in PD. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Clinico-imaging features of subjects at risk of Lewy body disease in NaT-PROBE baseline analysis

Individuals with prodromal symptoms of Lewy body disease (LBD), such as rapid eye movement sleep behavior disorder (RBD), often showed imaging defects similar to patients with Parkinson’s disease and dementia with Lewy bodies. We examined dopamine transporter (DaT) single-photon-emission computed tomography (SPECT) and metaiodobenzylguanidine (MIBG) scintigraphy in 69 high-risk subjects with ≥2 prodromal symptoms (dysautonomia, hyposmia, and probable RBD) and 32 low-risk subjects without prodromal symptoms, whom were identified through a questionnaire survey of health checkup examinees. The high-risk subjects had significantly worse scores on Stroop test, line orientation test, and the Odor Stick Identification Test for Japanese than the low-risk subjects. The prevalence of abnormalities on DaT-SPECT was higher in the high-risk group than in the low-risk group (24.6% vs. 6.3%, p = 0.030). A decreased uptake on DaT-SPECT was associated with motor impairment, and MIBG scintigraphy defects were associated with hyposmia. The simultaneous evaluation of DaT-SPECT and MIBG scintigraphy may capture a wide range of individuals with prodromal LBD.

Properties of odor identification testing in screening for early-stage Alzheimer’s disease

Odor identification (OI) is impaired in the early stages of Alzheimer’s disease (AD). However, data regarding the diagnostic properties of OI tests are lacking, preventing their clinical use. We aimed to explore OI and determine the accuracy of OI testing in screening for patients with early AD. In total, 30 participants with mild cognitive impairment due to AD (MCI-AD), 30 with mild dementia due to AD (MD-AD), and 30 cognitively normal elderly participants (CN) were enrolled, and cognitive examination (CDR, MMSE, ADAS-Cog 13, and verbal fluency tests) and assessment of OI (Burghart Sniffin’ Sticks odor identification test) were performed. MCI-AD patients scored significantly worse in OI than CN participants, and MD-AD patients had worse OI scores than MCI-AD patients. The ratio of OI to ADAS-Cog 13 score had good diagnostic accuracy in differentiating AD patients from CN participants and in differentiating MCI-AD patients from CN participants. Substitution of ADAS-Cog 13 score with the ratio of OI to ADAS-Cog 13 score in a multinomial regression model improved the classification accuracy, especially of MCI-AD cases. Our results confirmed that OI is impaired during the prodromal stage of AD. OI testing has a good diagnostic quality and can improve the accuracy of screening for early-stage AD.

Olfactory impairment in COVID-19: Two methods for the assessment of olfactory function

BackgroundOlfactory impairment is a major symptom of COVID-19. Is it necessary for COVID-19 patients to perform the detection of olfactory function, even how to select the olfactory psychophysical assessment tool. MethodsPatients infected with SARS-CoV-2 Delta variant were firstly taken into three categories (mild, moderate, and severe) according to the clinical classification. The Odor Stick Identification Test for the Japanese (OSIT-J) and the Simple Olfactory Test were used to assess olfactory function. Moreover, these patients were divided into three groups based on the results of the olfactory degree (euosmia, hyposmia, and dysosmia), too. The statistical analysis of the correlations between olfaction and clinical characteristics of patients were performed. ResultsOur study demonstrated that the elderly men of Han were more susceptible to infected SARS-CoV-2, the clinical symptoms of the COVID-19 patients showed a clear correspondence with the disease type and the degree of olfactory disturbance. Whether or not to vaccinate and whether to complete the whole course of vaccination was closely related to the patient's condition. OSIT-J Test and Simple Test were consistent in our work, indicating that olfactory grading would worsen with the aggravation of symptoms. Furthermore, the OSIT-J method maybe better than Simple Olfactory Test. ConclusionThe vaccination has an important protective effect on the general population, and vaccination should be vigorously promoted. Moreover, it is necessary for COVID-19 patients to perform the detection of olfactory function, and the easier, faster and less expensive method for determination of olfactory function should be utilized to COVID-19 patients as the vital physical examination.

Chemosensory Functions After Glossectomy-A Cross-Sectional Pilot Study.

To evaluate potential interactions and compensatory mechanisms of subjectively impaired taste function with ortho- and retronasal olfaction after glossectomy. In this cross-sectional pilot study, chemosensory functions were assessed in 25 patients with tongue carcinomas after glossectomy. The orthonasal-, retronasal-, and gustatory functions were tested with a mean time of 25 months after surgery with the Sniffin' Sticks odor identification test kit (ISST), the Candy Smell-27 test (CST-27) and the Taste strip test (TST). Visual analog scales (VAS) were additionally used for self-assessment of taste, flavor perception, and odor ranging from 0 (no perception) to 10 (excellent perception) and further correlated with our psychophysical evaluated outcome measures. The TST, ISST, and CST-27 tests revealed that only eight (32%) and 13 (52%) glossectomy patients had normal taste and orthonasal function, e 21 (84%) patients showed normal retronasal function. Importantly, neither extent of resection and reconstruction nor prior radiotherapy affected chemosensory functions. Contrary, 20 (80%) patients rated their taste and flavor perception as acceptable (VAS >5). Results of the TST, ISST, and CST-27 tests did not correlate with the equivalent self-assessments of taste (p=0.260, r=0.234), odor (p=0.588, r=-0.114), and flavor (p=0.728, r=0.073) perception. There was a significant discrepancy between self-perception of taste and flavor and assessed gustatory function after glossectomy. A contribution of the intact retronasal olfactory system could be a possible explanation of our results. 4 Laryngoscope, 133:375-382, 2023.

The Neuroanatomic Correlates of Olfactory Identification Impairment in Healthy Older Adults and in Persons with Mild Cognitive Impairment.

Olfactory identification (OI) impairment appears early in the course of Alzheimer's disease dementia (AD), prior to detectable cognitive impairment. However, the neuroanatomical correlates of impaired OI in cognitively normal older adults (CN) and persons with mild cognitive impairment (MCI) are not fully understood. We examined the neuroanatomic correlates of OI impairment in older adults from the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS). Our sample included 1,600 older adults without dementia who completed clinical assessment and structural brain imaging from 2011 to 2013. We characterized OI impairment using the 12-item Sniffin' Sticks odor identification test (score ≤6). We used voxel-based morphometry (VBM) and region of interest (ROI) analyses to examine the neuroanatomic correlates of impaired OI in CN and MCI, after adjusting for potential confounders. Analyses were also separately stratified by race and sex. In CN, OI impairment was associated with smaller amygdala gray matter (GM) volume (p &lt; 0.05). In MCI, OI impairment was associated with smaller GM volumes of the olfactory cortex, amygdala, entorhinal cortex, hippocampus, and insula (ps &lt; 0.05). Differential associations were observed by sex in MCI; OI impairment was associated with lower insular GM volumes among men but not among women (p-interaction = 0.04). There were no meaningful interactions by race. The brain regions associated with OI impairment in individuals without dementia are specifically those regions known to be the primary targets of AD pathogenic processes. These findings highlight the potential utility of olfactory assessment in the identification and stratification of older adults at risk for AD.

Associations of Prior Head Injury With Olfaction in Older Adults

Traumatic brain injury has been associated with short-term olfactory dysfunction, but the association of number of prior head injuries and head injury severity with both subjective and objective long-term olfactory function is less clear. To investigate the associations of prior head injury, number of prior head injuries, and head injury severity with subjective and psychophysical (objective) olfactory function in older adults and to examine concordance between subjective and objective olfactory function among individuals with and without head injury. This prospective cohort study included 5951 participants who attended Atherosclerosis Risk in Communities (ARIC) Study visit 5 (2011 through 2013). Data analysis was performed between November 2021 and May 2022. Head injury was defined by self-report and International Classification of Diseases codes. Self-reported subjective olfactory dysfunction was assessed by the question, "Do you suffer from smell loss or a significantly decreased sense of smell?" Objective olfactory performance was assessed using the 12-item Sniffin' Sticks odor identification test. Overall, the 5951 participants were a mean (SD) age of 75.6 (5.2) years, 3501 (58.8%) were female, 1356 (22.8%) were of Black race, and 1666 (28.0%) had a history of head injury. Participants with prior head injury were more likely than individuals without prior head injury to report subjective olfactory dysfunction (24% vs 20%; difference, 4%; 95% CI, 1% to 6%) and have objective anosmia (15% vs 13%; difference, 2%; 95% CI, 0.1% to 4%) but had lower concordance between subjective and objective assessment (72% vs 77%; difference, -5%; 95% CI, -8% to -3%). In logistic regression models adjusted for sociodemographics and medical comorbidities including cognitive status, participants with a history of prior head injury, particularly individuals with 2 or more prior head injuries and more severe head injuries, were more likely to self-report subjective olfactory dysfunction and were more likely to be found to have objective anosmia compared with participants with no history of head injury. Findings of this cohort study provide evidence supporting the association between head injury and olfactory dysfunction, particularly among individuals who experienced multiple prior head injuries and among individuals with more severe head injury. The findings also suggest that individuals with prior head injury were more likely to both under-self-report and over-self-report deficits compared with objective olfactory testing; therefore, it may be important to consider objective olfactory testing in this patient population.

Olfaction, ability to identify particular olfactory clusters and odors, and physical performance in community-dwelling older adults: The Yanai Study.

Olfactory dysfunction is associated with poor physical performance in older adults. However, it remains unknown whether the ability to identify particular olfactory clusters and/or odors is associated with physical performance in physically independent community-dwelling older adults. This cross-sectional study included 130 community-dwelling older adults (70.1±5.5years). The Odor Stick Identification Test for Japanese people, consisting of 12 odors in four clusters (wood, grass, herb; sweet; spices; foul-smelling), was used to examine olfaction. Participants also completed physical performance tests (one leg standing with open eyes; aerobic capacity; lower muscle function: five-times chair stand [CS] and vertical jump; mobility: star walking and timed up and go [TUG]) and cognitive function tests. Worse overall olfaction was not significantly associated with any physical performance measure. Worse performance for identifying sweet odors and an inability to identify some specific odors (menthol and rose) were associated with worse mobility and/or lower muscle function-adjusted covariates. Moreover, an inability to identify menthol and rose was associated with worse TUG (odds ratio [OR]: 0.424; 95% confidence interval [CI]: 0.215-0.836), star walking (OR: 0.714; 95% CI: 0.506-0.976), CS (OR: 0.638; 95% CI: 0.470-0.864), and vertical jump (OR: 1.12; 95% CI: 1.001-1.24) performance, even when the analysis was adjusted to exclude menthol and rose score from the overall olfaction score (p<.05 for all). The current study may help to increase awareness of olfactory and physical dysfunction at an earlier stage among physically independent community-dwelling older adults.

Long-term Olfactory Functions in Patients with Subjective Cognitive Decline and Mild Cognitive Impairment

IntroductionOlfactory function is known to be impaired in patients with Alzheimer’s disease (AD) as well as in subjective cognitive decline (SCD) and mild cognitive impairment (MCI), which are generally considered at-risk states for developing AD. The aim of the study at hand was to identify predictors of self-reported olfaction capability (SOC), self-reported capability of perceiving specific odors (SRP), olfaction-related quality of life (ORQ), and odor identification (OIT) in patients with SCD, naMCI, and aMCI.MethodsThe sample consisted of 33 patients with SCD, 88 with naMCI, and 43 with aMCI who consulted the Department of Neurology, Medical University of Vienna, due to memory complaints between January 2001 and May 2018. Olfactory function was assessed objectively by means of the Sniffin’ Sticks odor identification test (OIT) and subjectively by means of the ASOF-scores SOC, SRP, and ORQ at two to three points in time, with an average time interval of 39 months between the first and second examination, and 24 months between the second and third examination. Linear mixed models were used in order to identify clinical and demographic variables as predictors of mean SOC, SRP, ORQ, and OIT throughout the observation period.ResultsThere was a statistically significant — albeit small — time-related decline of SOC and ORQ in the SCD group but not in other groups. Throughout the observation period, estimated ORQ was significantly higher in the SCD group than in the naMCI and estimated OIT was significantly higher in the naMCI group than in the aMCI group after adjusting for time of measurement and other covariates. Positive relationships between OIT and all three ASOF-scores, negative relationships between BDI-II and SOC and ORQ, and a positive relationship between WST-IQ and SRP were identified.ConclusionThere is a statistically significant, albeit small, time-related decline of uncertain clinical relevance in subjective measures of olfactory capability and olfaction-related quality of life in patients with SCD.ImplicationsIn all subgroups, objectively measured odor-identification scores have a significant impact on subjective scores over time. The study at hand confirms previous observations regarding the negative influence of depression on subjective perception of olfactory capabilities known from cross-sectional studies.

Olfaction, Cognitive Impairment, and PET Biomarkers in Community-Dwelling Older Adults.

Olfactory deficits are early features of preclinical Alzheimer's disease (AD). Whether olfaction is associated with PET biomarkers among community-dwelling older adults is less clear. Investigate cross-sectional and longitudinal associations of olfaction with mild cognitive impairment (MCI) and amyloid-β (Aβ) and tau deposition. We analyzed 364 initially cognitively normal participants (58% women, 24% black) who had baseline olfaction data and subsequent cognitive assessments during an average 2.4-year. A subset of 129 had PET-PiB (Aβ) (n = 72 repeated) and 105 had 18F-flortaucipir (FTP)-PET (tau) (n = 44 repeated). Olfaction was measured using a 16-item Sniffin' Sticks Odor Identification Test. The association of olfaction with incident MCI was examined using Cox regression. Associations with PiB-distribution volume ratio (DVR) and FTP-standardized uptake value ratio (SUVR) were examined using partial correlation. We tested whether PiB+/-status modified these associations. Analyses were adjusted for demographics and olfactory test version. 17 (5%) participants developed MCI. Each unit lower odor identification score was associated with 22% higher risk of developing MCI (p = 0.04). In the PET subset, lower scores were associated with higher mean cortical DVR and DVR in orbitofrontal cortex (OFC), precuneus, and middle temporal gyrus (p≤0.04). The "olfaction*PiB+/-" interaction in OFC DVR was significant (p = 0.03), indicating the association was limited to PiB positive individuals. Greater decline in odor identification score was associated with greater increase in anterior OFC DVR and entorhinal tau SUVR (p≤0.03). Among community-dwelling older adults, poorer olfaction predicts incident MCI and is associated with overall and regional Aβ. Greater olfaction decline is associated with faster Aβ and tau accumulation in olfaction-related regions. Whether olfaction predicts AD-related neurodegenerative changes warrants further investigations.

Evaluation of olfactory impairment using a simple test kit &#8220; The Odor Stick Identification test for the Japanese &#8221; (OSIT-J) in neurodegenerative diseases

Evaluation of olfactory impairment using a simple test kit &#8220; The Odor Stick Identification test for the Japanese &#8221; (OSIT-J) in neurodegenerative diseases