Impact of post-COVID-19 olfactory disorders on quality of life, hedonic experiences and psychiatric dimensions in general population.

BACKGROUND AND OBJECTIVE: Olfactory disorders in COVID-19 impact quality of life and may lead to psychological impairments. Prevalence ranges from 8 to 85%, persisting in about 30% of cases. This study aimed to evaluate the 6-month post-COVID-19 impact on quality of life, hedonic experiences, anxiety and depression due to olfactory disorders. Additionally, it sought to compare psychophysical tests and self-perceived olfactory evaluations. METHODS: A prospective, longitudinal study was conducted over baseline (T0) and 6 months (T1) on individuals with persistent olfactory disorders post-COVID-19 for more than 6 weeks. Psychophysical tests employed the Sniffin' Sticks Test® (TDI score), and self-perceived olfactory evaluation used a Visual Analogue Scale. Quality of life was assessed with an Olfactive Disorder Questionnaire and the French version of the Quality of Life and Diet Questionnaire. Hedonic experiences were gauged using the Snaith-Hamilton Pleasure Scale, while anxiety and depression dimensions were measured by The State-Trait Anxiety Inventory, The Post Traumatic Stress Checklist Scale, and Hamilton Rating Scale for Depression. Participants were classified into the "normosmic group" (NG) and the "olfactory disorders group" (ODG) at T0 and T1 based on the TDI score. RESULTS: Were included 56 participants (58.93% women, 41.07% men) with a mean age of 39.04 years and a mean duration of post-COVID-19 olfactory disorders of 5.32 months. At T1, ODG had a significantly lower quality of life and hedonic experiences than NG. No significant differences in anxiety and depression dimensions were observed between groups. At T0, psychophysical tests and self-perceived olfactory evaluations were significantly correlated with quality of life and hedonic experiences in both groups. At T1, self-perceived olfactory evaluation in NG correlated significantly with quality of life, hedonic experiences, anxiety and depression dimensions, whereas ODG only correlated with hedonic experiences. CONCLUSION: Individuals with persistent post-COVID-19 olfactory disorders after six months demonstrated compromised quality of life and hedonic experiences. Self-perceived olfactory evaluation played a more significant role in influencing quality of life and the dimension of anxiety and depression than the psychophysical presence of olfactory disorders. These findings emphasize the importance of considering patients' perceptions to comprehensively assess the impact of olfactory disorders on their well-being. TRIAL REGISTRATION: ClinicalTrials.gov number (ID: NCT04799977).

Characteristics of higher depressive tendency in the patients with olfactory disorder.

OBJECTIVE: Most patients with olfactory dysfunction experience stress and anxiety because of the inconvenience and changes caused by the loss of olfaction. However, psychological assessment is not performed routinely in patients with olfactory dysfunction, and the characteristics of these patients with psychological depression are unclear. METHODS: In this study, we used the Self-rating Depression Scale to evaluate the degree of depression in patients who visited our clinic with olfactory dysfunction and examine the characteristics of these patients with strong depressive tendencies. Patients who visited our clinic between April 2019 and March 2020 with complaints of olfactory dysfunction were included in the study. RESULTS: A total of 180 patients (79 male and 101 female) underwent olfactory examination and completed the Self-rating Depression Scale. Eighty-six and 94 patients were included in the low depression and high depression groups, respectively. Binomial logistic regression analysis showed significant positive associations of Self-rating Depression Scale scores with female sex and the presence of parosmia/phantosmia (p < 0.05). CONCLUSION: In our study, approximately half of the patients with olfactory dysfunction had depressive tendencies especially in female and parosmia/phantosmia patients. We believe that psychological assessments, such as that with the SDS, can help identify patients with olfactory dysfunction who may be at a greater risk of developing depression.

COVID-19 olfactory dysfunction: associations between coping, quality of life, and mental health.

BACKGROUND: Persistent olfactory dysfunction (OD) is a common symptom following SARS-CoV-2 infection that can greatly impact quality of life (QoL). Because coping strategies have been shown to moderate the effect of disease symptoms on functional and affective outcomes, this study aims to determine whether specific coping strategies are associated with and moderate QoL outcomes. METHODOLOGY: Participants with prior SARS-CoV-2 infection underwent psychophysical olfactory testing with Sniffin’ Sticks and completed questionnaires to elicit subjective olfactory function, coping strategies, olfactory-specific QoL, general QoL, and mental health. RESULTS: There were 93 participants included in the study. Olfactory specific QoL scores were significantly worse among individuals with subjective and psychophysically measured OD compared to those with subjective and psychophysically confirmed normosmia. Olfactory-specific QoL, general QoL, and anxiety symptom scores were positively correlated with avoidant and disengagement coping among individuals with subjective and psychophysically measured OD. Depression symptom scores were positively correlated with avoidant and disengagement coping and negatively correlated with approach and engagement coping. There were no significant moderating effects on the association between olfactory performance and QoL or mental health screening assessment. CONCLUSIONS: Approach and engagement coping mechanisms are associated with improved depression, whereas avoidant and disengagement coping tracks with worse QoL and mental health screening assessment, offering an opportunity to counsel patients accordingly.

Olfactory training effects in children after mild traumatic brain injury.

OBJECTIVE: Mild traumatic brain injury (mTBI) might impair the sense of smell and cognitive functioning. Repeated, systematic exposure to odors, i.e., olfactory training (OT) has been proposed for treatment of olfactory dysfunctions, including post-traumatic smell loss. Additionally, OT has been shown to mitigate cognitive deterioration in older population and enhance selected cognitive functions in adults. We aimed to investigate olfactory and cognitive effects of OT in the pediatric population after mTBI, likely to exhibit cognitive and olfactory deficits. METHODS: Our study comprised 159 children after mTBI and healthy controls aged 6-16 years (M = 9.68 ± 2.78 years, 107 males), who performed 6-months-long OT with a set of 4 either high- or low-concentrated odors. Before and after OT we assessed olfactory functions, fluid intelligence, and executive functions. RESULTS: OT with low-concentrated odors increased olfactory sensitivity in children after mTBI. Regardless of health status, children who underwent OT with low-concentrated odors had higher fluid intelligence scores at post-training measurement, whereas scores of children performing OT with high-concentrated odors did not change. CONCLUSION: Our study suggests that OT with low-concentrated odors might accelerate rehabilitation of olfactory sensitivity in children after mTBI and support cognitive functions in the area of fluid intelligence regardless of head trauma.

Olfactory impairment in mild cognitive impairment with Lewy bodies and Alzheimer's disease.

OBJECTIVES: Impaired olfaction may be a biomarker for early Lewy body disease, but its value in mild cognitive impairment with Lewy bodies (MCI-LB) is unknown. We compared olfaction in MCI-LB with MCI due to Alzheimer's disease (MCI-AD) and healthy older adults. We hypothesized that olfactory function would be worse in probable MCI-LB than in both MCI-AD and healthy comparison subjects (HC). DESIGN: Cross-sectional study assessing olfaction using Sniffin' Sticks 16 (SS-16) in MCI-LB, MCI-AD, and HC with longitudinal follow-up. Differences were adjusted for age, and receiver operating characteristic (ROC) curves were used for discriminating MCI-LB from MCI-AD and HC. SETTING: Participants were recruited from Memory Services in the North East of England. PARTICIPANTS: Thirty-eight probable MCI-LB, 33 MCI-AD, 19 possible MCI-LB, and 32HC. MEASUREMENTS: Olfaction was assessed using SS-16 and a questionnaire. RESULTS: Participants with probable MCI-LB had worse olfaction than both MCI-AD (age-adjusted mean difference (B) = 2.05, 95% CI: 0.62-3.49, p = 0.005) and HC (B = 3.96, 95% CI: 2.51-5.40, p < 0.001). The previously identified cutoff score for the SS-16 of ≤ 10 had 84% sensitivity for probable MCI-LB (95% CI: 69-94%), but 30% specificity versus MCI-AD. ROC analysis found a lower cutoff of ≤ 7 was better (63% sensitivity for MCI-LB, with 73% specificity vs MCI-AD and 97% vs HC). Asking about olfactory impairments was not useful in identifying them. CONCLUSIONS: MCI-LB had worse olfaction than MCI-AD and normal aging. A lower cutoff score of ≤ 7 is required when using SS-16 in such patients. Olfactory testing may have value in identifying early LB disease in memory services.

Reliability and validity of a brief version of the Questionnaire of Olfactory Disorders (brief QOD) in patients with olfactory dysfunction.

BACKGROUND: The aim of this study was to determine the reliability and validity of the brief version of Questionnaire of Olfactory Disorders (brief QOD). METHODS: A total of 372 patients participated in this study. Olfactory function was examined using the Sniffin' Sticks test. The brief version of QOD, including 4 items concerning parosmia (QOD-P), 7 items concerning quality of life (QOD-QOL), and 3 visual analog scales to rate disease burden, awareness of the disorder and issues related to professional life (QOD-VAS), was used to assess subjective information on olfactory dysfunction. We evaluated the split-half reliability, internal consistency and validity of the brief QOD. RESULTS: The split-half reliability was 0.60 (QOD-P), 0.87 (QOD-QOL), and 0.66 (QOD-VAS), respectively. The Cronbach's coefficient was 0.63 (QOD-P), 0.87 (QOD-QOL), and 0.71 (QOD-VAS), respectively. Olfactory function was found to be associated with QOD-P, QOD-QOL and QOD-VAS. CONCLUSIONS: The brief QOD is a suitable scale for the assessment of subjective severity of olfactory dysfunction for purposes such as treatment counseling, disability assessment, treatment control, and research in patients with olfactory disorder.

Olfactory Impairment and Close Social Relationships. A Narrative Review.

Olfactory impairment is one of the more unique symptoms of COVID-19 infection and has therefore enjoyed increased public attention in recent months. Olfactory impairment has various implications and consequences ranging from difficulty detecting dangerous pathogens to hindering social functioning and social behaviors. We provide an overview of how olfactory impairment can impact 3 types of close social relationships: family relationships, friendships, and romantic relationships. Evidence is divided into several categories representing potential mechanisms by which olfactory impairment can impact close social relationships: bonding disruptions, decreased social support, missed group-eating experiences, hygiene concerns, and altered sexual behaviors. We conclude with a discussion of emerging future research questions.

Differences in taste and smell perception between type 2 diabetes mellitus patients and healthy controls.

BACKGROUND AND AIMS: The senses of taste and smell are essential determinants of food choice, which in turn may contribute to the development of chronic diseases, including diabetes. Although past studies have evaluated the relationship between type 2 diabetes mellitus (DM2) and senses disorders, this relationship remains controversial. In this study, we evaluated taste and smell perception in DM2 patients and healthy controls (HC). Moreover, we analyzed the association of chemosensory impairments with anthropometric and clinical outcomes (e.g. Body Mass Index (BMI), Fasting blood glucose (FBG), drugs, cardiovascular diseases (CVD), and hypertension) in DM2 patients. METHODS AND RESULTS: The study included 94 DM2 patients and 244 HC. Taste recognition for 6-n-propylthiouracil (PROP), quinine, citric acid, sucrose, and sodium chloride (NaCl) compounds was assessed using a filter paper method, while smell recognition of 12 odorants was performed using a Sniffin' sticks test. We found that a higher percentage of DM2 patients showed identification impairment in salt taste (22% vs. 5%, p-value<0.0009) and smell recognition (55% vs. 27%, p-value = 0.03) compared to HC. We also observed that 65% of hypertensive DM2 subjects presented smell identification impairment compared to 18% of non-hypertensive patients (p-value = 0.019). Finally, patients with impairments in both taste and smell showed elevated FBG compared to patients without impairment (149.6 vs.124.3 mg/dL, p-value = 0.04). CONCLUSION: The prevalence of taste and smell identification impairments was higher in DM2 patients compared to HC, and a possible relationship with glycemic levels emerged.

Quality of life and safety impact of COVID-19 associated smell and taste disturbances.

OBJECTIVE: The association between COVID-19 and chemosensory loss has garnered substantial attention, however to date little is known about the real-life consequences of impairment in this unique patient population. The aim of this study is to evaluate the quality of life (QOL) and personal safety deficits experienced by patients with COVID-19 infection. STUDY DESIGN: Prospective, longitudinal questionnaires. SETTING: National survey. METHODS: A longitudinal web-based nationwide survey of adults with COVID-19 and/or a sudden change in smell and taste was launched April 10, 2020. Previously published questions on chemosensory-related QOL and safety events were asked at the 6-month follow-up survey. RESULTS: As of February 10, 2021, 480 eligible respondents took the 6-month questionnaire, of whom 322 were COVID-19 positive. Impact on QOL was substantial with 96% of subjects reporting at least one of the defined deficits, and over 75% reporting at least 3 of these. "Reduced enjoyment of food" was the most common complaint (87%), while 43% of subjects self-reported depression. The prevalence of safety-related issues was common in this population, with over 57% reporting at least one, and 36% reporting 2 or more events. Of the events asked, the inability to smell smoke that others could perceive was the most common at 45%. CONCLUSIONS: COVID-19 associated chemosensory losses have a real and substantial impact on both quality of life and safety, beyond mere inconvenience. The high prevalence of these issues despite a relatively short period of olfactory deficit should alert clinicians to the serious risks to an already vulnerable patient population.

Olfaction contributes to the learned avidity for glucose relative to fructose in mice.

When offered glucose and fructose solutions, rodents consume more glucose solution because it produces stronger postoral reinforcement. Intake of these sugars also conditions a higher avidity for glucose relative to fructose. We asked which chemosensory cue mediates the learned avidity for glucose. We subjected mice to 18 days of sugar training, offering them 0.3, 0.6, and 1 M glucose and fructose solutions. Before and after training, we measured avidity for 0.3 and 0.6 M glucose and fructose in brief-access lick tests. First, we replicated prior work in C57BL/6 mice. Before training, the mice licked at a slightly higher rate for 0.6 M fructose; after training, they licked at a higher rate for 0.6 M glucose. Second, we assessed the necessity of the glucose-specific ATP-sensitive K+ (KATP) taste pathway for the learned avidity for glucose, using mice with a nonfunctional KATP channel [regulatory sulfonylurea receptor (SUR1) knockout (KO) mice]. Before training, SUR1 KO and wild-type mice licked at similar rates for 0.6 M glucose and fructose; after training, both strains licked at a higher rate for 0.6 M glucose, indicating that the KATP pathway is not necessary for the learned discrimination. Third, we investigated the necessity of olfaction by comparing sham-treated and anosmic mice. The mice were made anosmic by olfactory bulbectomy or ZnSO4 treatment. Before training, sham-treated and anosmic mice licked at similar rates for 0.6 M glucose and fructose; after training, sham-treated mice licked at a higher rate for 0.6 M glucose, whereas anosmic mice licked at similar rates for both sugars. This demonstrates that olfaction contributes significantly to the learned avidity for glucose.

Impaired olfactory identification and hedonic judgment in schizophrenia patients with prominent negative symptoms.

Introduction: Evidence suggests that schizophrenia patients have olfactory dysfunctions, but the relationship between olfactory identification, hedonic judgement, and negative symptomatology remains unclear. Few studies have investigated whether co-activation of pleasant and unpleasant emotions are more prevalent in schizophrenia patients.Methods: Thirty schizophrenia outpatients with prominent negative symptoms (PNS), 30 outpatients without PNS, and 30 controls completed the University of Pennsylvania Smell Identification Test, and were asked to identify the odourants and to rate their emotions. The effects of gender and medications on olfactory function were examined.Results: Schizophrenia patients exhibited olfactory identification impairments, even after accounting for gender and medication effects. Patients with PNS demonstrated larger magnitude of deficit than those without. Patients with PNS reported less pleasure to positive-valenced odourants, and less unpleasantness to negative-valenced odourants than controls. Olfactory anhedonia in patients with PNS disappeared after controlling for medication effect. Schizophrenia patients do not exhibit affective ambivalence in olfaction.Conclusions: Schizophrenia patients with PNS exhibit deficits in olfactory identification and hedonic judgement, even after controlling for gender and medication effects. Our findings support the close relationship between olfactory dysfunctions and negative symptoms. Further studies should investigate the effect of dopamine-blocking agents on the olfactory hedonic judgment in schizophrenia patients.

[Appreciating COVID-19 as a child and adolescent psychiatrist on the move]. / Appréhender le COVID-19 au fil de l'eau en tant que psychiatre d'enfant et d'adolescent.

COVID-19 is a multi-organ disease due to an infection with the SARS-CoV2 virus. It has become a pandemic in early 2020. The disease appears less devastating in children and adolescents. However, stress, quarantine and eventually mourning have major impacts on development. It is difficult to describe what this pandemic implies for a child psychiatrist, other than by giving a first-hand account. I propose to go through the main ethical questions that have arisen; to describe how my hospital team has reorganized itself to meet the new demands and questions, in particular by opening a unit dedicated to people with autism and challenging behaviors affected by COVID-19; and to address, in a context of national discussion, how the discipline has sought to understand the conditions of a certain well-being during quarantine. Finally, I will try to conclude with more speculative reflections on re-opening.

Intranasal administration of white tea alleviates the olfactory function deficit induced by chronic unpredictable mild stress.

CONTEXT: White tea [Camellia sinensis (L) O.Ktze. (Theaceae)] is popular in Asia, but its benefits on olfactory injury are unknown. OBJECTIVE: The present study explores the effects of white tea on the olfactory injury caused by chronic unpredictable mild stress (CUMS). MATERIALS AND METHODS: C57BL/6J mice (WT) were exposed to CUMS. CUMS mice (CU) were intranasally treated with white tea extract [low tea (LT), 20 mg/kg; high tea (HT), 40 mg/kg] and fluoxetine (CF, 20 mg/kg) for 7 days. Several behavioural tests were conducted to assess depression and olfactory function. The transmission electron microscope (TEM) and semi-quantitative reverse transcription PCR were performed separately to observe the changes of related structures and genes transcription level. RESULTS: The depressive behaviours of the LT and HT mice were reversed. The latency time of the buried food pellet test decreased from 280 s (CU) to 130 s (HT), while the olfactory sensitivity and olfactory avoidance test showed that the olfactory behaviours disorder of LT and HT mice were alleviated. The white tea increased the A490 nm values of the cortisol treated cells from 0.15 to 1.4. Reduced mitochondrial and synaptic damage in the olfactory bulb (OB), enhanced expression of the brain-derived neurotrophic factor (BDNF) and olfactory marker protein (OMP) were observed in the LT and HT mice. CONCLUSIONS AND DISCUSSION: White tea has the potential in curing the olfactory deficiency related to chronic stress. It lays the foundation for the development of new and reliable drug to improve olfactory.

A Quantitative Meta-analysis of Olfactory Dysfunction in Epilepsy.

Olfactory dysfunction in epilepsy is well-documented in several olfactory domains. However, the clinical specificity of these deficits remains unknown. The aim of this systematic meta-analysis was to determine which domains of olfactory ability were most impaired in individuals with epilepsy, and to assess moderating factors affecting olfactory ability. Extant peer-reviewed literature on olfaction in epilepsy were identified via a computerized literature search using PubMed, MEDLINE, PsycInfo, and Google Scholar databases. Twenty-one articles met inclusion criteria. These studies included a total of 912 patients with epilepsy and 794 healthy comparison subjects. Included studies measured olfaction using tests of odor identification, discrimination, memory, and detection threshold in patients with different types of epilepsy, including temporal lobe epilepsy (TLE), mixed frontal epilepsy (M-F), and mixed epilepsy (MIX). Olfactory deficits were robust in patients with epilepsy when compared to healthy individuals, with effect sizes in the moderate to large range for several olfactory domains, including odor identification (d = -1.59), memory (d = -1.10), discrimination (d = -1.04), and detection threshold (d = -0.58). Olfactory deficits were most prominent in patients with TLE and M-F epilepsy. Amongst patients with epilepsy, sex, age, smoking status, education, handedness, and age of illness onset were significantly related to olfactory performance. Overall, these meta-analytic findings indicate that the olfactory system is compromised in epilepsy and suggest that detailed neurobiological investigations of the olfactory system may provide further insight into this disorder.

Cognitive decline in association with hyposmia in idiopathic rapid eye movement sleep behavior disorder: a prospective 2-year follow-up study.

BACKGROUND AND PURPOSE: The aim was to analyze the characteristics and progression of cognitive dysfunction in non-demented idiopathic rapid eye movement sleep behavior disorder (iRBD) patients with baseline olfactory function. METHODS: From a prospective polysomnography-confirmed iRBD cohort, 25 patients (16 patients in 2-year follow-up) and 13 normal controls were included. Initial and 2-year follow-up cognitive functions were analyzed with olfactory function and 18 F-fluorinated-N-3-fluoropropyl-2ß-carboxymethoxy-3ß-(4-iodophenyl)-nortropane (18 F-FP-CIT) uptake in deep nuclei initially. RESULTS: Idiopathic RBD patients had impaired attention, memory and executive function compared to controls. Baseline cognitive tests were comparable between the iRBD subgroups with and without hyposmia. 18 F-FP-CIT uptake tended to be lower in the hyposmic group than in the normosmic group. The olfactory test score was positively correlated with amygdala uptake in iRBD patients (P = 0.027). After 2 years, visuospatial and verbal memory dysfunction worsened more in hyposmics than in normosmics. Lower initial olfactory test score was associated with more severe declines in verbal memory function. CONCLUSIONS: Hyposmia may be a predictive sign of cognitive decline in iRBD patients.

Identification of odors, faces, cities and naming of objects in patients with subjective cognitive decline, mild cognitive impairment and Alzheimer´s disease: a longitudinal study.

ABSTRACTObjective:Recent studies have tried to find a reliable way of predicting the development of Alzheimer´s Disease (AD) among patients with mild cognitive impairment (MCI), often focusing on olfactory dysfunction or semantic memory. Our study aimed to validate these findings while also comparing the predictive accuracy of olfactory and semantic assessments for this purpose. METHOD: Six hundred fifty patients (median age 68, 58% females) including controls, SCD (subjective cognitive decline), non-amnestic MCI (naMCI), amnestic MCI (aMCI), and AD patients were tested for olfactory dysfunction by means of odor identification testing and semantic memory. Of those 650 patients, 120 participants with SCD, naMCI, or aMCI at baseline underwent a follow-up examination after two years on average. Of these 120 patients, 12% had developed AD at follow-up (converters), while 88% did not develop AD at follow-up (non-converters). RESULTS: Analysis showed a significant difference only for initial olfactory identification between converters and non-converters. Sensitivity of impairment of olfactory identification for AD prediction was low at 46.2%, although specificity was high at 81.9%. Semantic memory impairment at baseline was not significantly related to AD conversion, although, when naming objects, significant differences were found between AD patients and all other groups and between naMCI and aMCI patients compared to controls and SCD patients. CONCLUSIONS: Objective olfactory assessments are promising instruments for predicting the conversion to AD among MCI patients. However, due to their low sensitivity and high specificity, a combination with other neuropsychological tests might lead to an improved predictive accuracy. Further longitudinal studies with more participants are required to investigate the usefulness of semantic memory tests in this case.

Olfactory, cognitive and affective dysfunction assessed 24 hours and one year after a mild Traumatic Brain Injury (mTBI).

Objective: This cross-sectional study aimed to evaluate olfaction 24 h (baseline) and 1 year (follow-up) after a mild traumatic brain injury (TBI). We further evaluated the influence of the cognition and affective state on olfactory function. Method: At baseline, olfactory function, neuropsychological, and affective states were assessed in 42 patients (20 mild TBI; 22 orthopedic injury). At follow-up, 12 patients with mild TBI and 7 controls could be included, and we assessed olfactory function, affective states, and post-concussion symptoms. Results: At baseline, patients with mild TBI demonstrated significantly reduced olfactory function, compared to controls, with more than 55% of the patients presenting signs of hyposmia. One year later, no significant differences in olfactory scores between cases and controls were observed. However, patients with mild TBI who had exhibited hyposmia at baseline exhibited significantly higher anxiety levels and more post-concussion symptoms than patients with mild TBI with normal olfactory function at baseline. Conclusions: In the acute phase of mild TBI a majority of patients has impaired olfactory function. Further patients with olfactory dysfunction are more likely to exhibit post-concussion and anxious symptoms at follow-up. Olfactory testing in the acute phase may therefore serve as a screening tool for long-term outcome.

Olfactory dysfunction: properties of the Sniffin' Sticks Screening 12 test and associations with quality of life.

PURPOSE: The Sniffin' Sticks Screening 12 test is a test of olfactory performance based on pen-like odor dispensing devices. The aims of this study were to analyze the performance of this test in a general population sample and to explore associations between olfactory dysfunction and quality of life. METHODS: A large community sample (n = 7267) completed the Sniffin' Sticks Screening 12 test and several questionnaires measuring quality of life, anxiety, dispositional optimism, social support, and satisfaction with life. RESULTS: According to the criteria recommended by the test manufacturer, 5.1% of the participants were anosmic (score ≤ 6), 52.4% were dysosmic (7 ≤ score ≤ 10), and 42.5% were normosmic (score ≥ 11). While frequencies of correct identification differed between the 12 sticks, all sticks contributed positively to the test results. The associations between olfactory functioning and quality of life variables were negligible. In the multivariate analyses, none of the associations reached the 1% significance level. CONCLUSIONS: While studies with patients in otorhinolaryngological clinics often report substantial detriments to their quality of life in relation to olfactory dysfunction, the present epidemiological study cannot confirm this association for the general population.

Whose nose does not know? Demographical characterization of people unaware of anosmia.

PURPOSE: For functionally anosmic subjects, the sense of smell is basically useless in daily activities-they are unlikely to detect the threatening smell of rotten food, gas or smoke, or to enjoy the flavor of food or the smell of perfumes. Although this appears very distressing, functionally anosmic subjects in our sample seemed not to be aware or bothered with impaired olfaction and enrolled for the study targeted to people with a normal sense of smell. METHODS: In the large sample of 9139 subjects who declared themselves to have a normal sense of smell, we have retrospectively found a notable proportion of scores indicating functional anosmia. RESULTS: When we look at the overall Sniffin' Sticks score, 0.45% of the sample was functionally anosmic and this fraction increased to 3.4% when the identification score of 8 points and below was used. We present demographical information of those subjects, who despite their inability to use smell in daily life, consider themselves healthy. CONCLUSIONS: Data offer a new perspective on the importance of olfaction in daily life and supports the notion about the importance of using screening tools in clinical practice.

Influence of olfactory dysfunction on the perception of food.

PURPOSE: Eating-related problems are among the most frequent issues in olfactory impairment, causing a noticeable loss of quality of life for some of the affected persons. To what extent olfactory dysfunction impacts on the sensory perception of food is less explored. The aim of the present study was to examine the impact of olfactory dysfunction on the perception of food aromas, as well as the perception of the "basic tastes" salty, sour, sweet, and bitter. METHODS: Eighty-nine participants were recruited for the prospective study. Group 1 consisted of thoroughly examined patients with olfactory dysfunction (n = 48, mean age = 60.0 years), group 2 consisted of people with normal olfactory function (n = 41, mean age = 50.4 years). First, olfactory and gustatory functions were assessed for all participants with the help of the "Sniffin'Sticks" battery and the "taste strips" test. Second, food odors were rated for their pleasantness, intensity, familiarity and desirability. Last, real food items were tasted orally and the intensity for basic taste qualities (sweet, bitter, salty, and sour) and pleasantness was rated. In addition, salivation was measured following exposure to the food odors. RESULTS: In comparison to controls, patients rated orthonasal food odors as less pleasant, intense, familiar, and less appetizing. "Taste strip" scores were significantly lower in patients (M = 9.56, SD = 2.76) as compared to controls (M = 10.88, SD = 1.89). In addition, ratings of food liking for chocolate and peanut were lower in patients compared to controls (chocolate: patients-M = 6.85, SD = 2.09, controls-M = 7.90, SD = 1.53; peanut: patients-M = 4.88, SD = 2.20, controls-M = 6.80, SD = 2.33). No significant differences were found regarding the comparison of the salivary flow rate in controls (M = 0.52 g/min, SD = 0.19) and patients (M = 0.50 SD = 0.17). CONCLUSIONS: Changes in the perception of odors may change the perception of food with specific effects on food liking. Olfactory dysfunction affects gustatory function, indicating the central-nervous interaction between taste and smell. Still, olfactory dysfunction did not appear to affect patients' salivary flow.