Characteristics of chemosensory disorders—results from a survey

Gene Methylation Affects Salivary Levels of the Taste Buds' Trophic Factor, Gustin Protein

The salivary protein, Gustin/carbonic anhydrase VI, has been described as a trophic factor responsible for the growth of taste buds. We found, in a genetically homogeneous population, that the polymorphism rs2274333 (A/G) of the Gustin gene is crucial for the full functionality of the protein and is associated with taste sensitivity. However, other studies have failed to find this evidence. Here, we verified if Gustin gene methylation can affect the salivary levels of the protein, also concerning the polymorphism rs2274333 and PROP bitter responsiveness. The Gustin gene methylation profiling and the quantification of the Gustin salivary levels were determined in sixty-six volunteers genotyped for the polymorphism rs2274333 (A/G) (Ser90Gly in the protein sequence). The fungiform papillae density was also determined. The results confirm our earlier observations by showing that AA genotypes had a greater density of fungiform taste papillae, whereas the GG genotypes showed a lower density. We also found variations in the protein levels in the three genotype groups and an inverse relationship between Gustin gene methylation and the salivary levels of the protein, mostly evident in AA and ST volunteers, i.e., in volunteers who would be carriers of the functional isoform of the protein. These findings could justify the conflicting data in the literature.

Olfactory Dysfunction Following Moderate to Severe Traumatic Brain Injury: A Systematic Review and Meta-Analysis

OBJECTIVE

Reports of smell loss following traumatic brain injury (TBI) are a well-documented but understudied phenomenon. Given the broad consequences of olfactory loss, we characterized psychophysical olfactory dysfunction in individuals with moderate to severe TBI using systematic review and meta-analytic methods.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) protocol, five databases (PubMed, EMBASE, Cochrane Library, Web of Science, Scopus) were reviewed for studies investigating olfactory dysfunction in persons with moderate to severe TBI. Of the 5,223 studies reviewed, 19 met our inclusion criteria for the systematic review and 11 met inclusion criteria for meta-analysis. We calculated effect sizes (Hedges' g) to characterize the degree of olfactory dysfunction between patients with moderate to severe TBI and controls.

RESULTS

A total of 951 moderate-severe TBI patients from 19 studies were included in the systematic review, which largely demonstrated poorer olfactory psychophysical performances in this patient population. Meta-analysis demonstrated a large effect size for olfactory dysfunction in moderate-severe TBI relative to healthy controls (g=-2.43, 95%CI: -3.16 < δ<-1.69). The magnitude of the effect was moderated by age and patient sex, with larger effect sizes associated with older age (following exclusion of a pediatric population) and larger compositions of women in the patient group.

CONCLUSION

Moderate to severe TBI is associated with prominent olfactory dysfunction. Significant research gaps remain regarding the mechanism, recovery and natural history of olfactory dysfunction following moderate to severe TBI, which has significant clinical implications for the identification and treatment for those with post-traumatic olfactory dysfunction.

Validity and Reliability of the Malay Questionnaire for Olfactory Disorders

Background

Olfactory disorders (OD) are an umbrella term for a diverse group of smell problems. Numerous tests and questionnaires have been formulated to identify and test the severity of smell impairment, which is not readily available or translated for the Malaysian population. This study aimed to translate the Questionnaire for Olfactory Disorders (QOD) and validate and test the reliability of the Malay Questionnaire for Olfactory Disorders (mQOD).

Methods

This cross-sectional study was conducted in two tertiary centres. A forward and backward translation was conducted for the QOD. The translated questionnaire was distributed to subjects with self-reported smell disorders on days 1 and 7. Internal consistency was analysed using Cronbach's alpha and test-retest reliability was tested with an intraclass correlation coefficient. Confirmatory factor analysis was performed to test construct validity.

Results

A total of 375 participants were recruited, 52 dropped out and 323 completed the questionnaire a second time. The Cronbach's alpha coefficient was 0.537 for parosmia (P), 0.892 for life quality (LQ), 0.637 for sincerity (S) and 0.865 for visual analogue score (VAS). The intraclass correlation coefficient (ICC) for domain scores was > 0.9, while the ICC for all items was good to excellent. A three-factor model for mQOD showed an acceptable fit with indices chi-square value (CMIN)/degree of freedom (DF) = 3.332, Tucker-Lewis fit index (TLI) = 0.923, comparative fit index (CFI) = 0.939, root mean square error of approximation (RMSEA) = 0.079 and standardised root mean square residual (SRMR) = 0.0574.

Conclusion

The mQOD is a valid and reliable tool for assessing OD in patients.

A supervised learning regression method for the analysis of oral sensitivity of healthy individuals and patients with chemosensory loss

The gustatory, olfactory, and trigeminal systems are anatomically separated. However, they interact cognitively to give rise to oral perception, which can significantly affect health and quality of life. We built a Supervised Learning (SL) regression model that, exploiting participants' features, was capable of automatically analyzing with high precision the self-ratings of oral sensitivity of healthy participants and patients with chemosensory loss, determining the contribution of its components: gustatory, olfactory, and trigeminal. CatBoost regressor provided predicted values of the self-rated oral sensitivity close to experimental values. Patients showed lower predicted values of oral sensitivity, lower scores for measured taste, spiciness, astringency, and smell sensitivity, higher BMI, and lower levels of well-being. CatBoost regressor defined the impact of the single components of oral perception in the two groups. The trigeminal component was the most significant, though astringency and spiciness provided similar contributions in controls, while astringency was most important in patients. Taste was more important in controls while smell was the least important in both groups. Identifying the significance of the oral perception components and the differences between the two groups provide important information to allow for more targeted examinations supporting both patients and healthcare professionals in clinical practice.

Suppression of sweet taste-related responses by plant-derived bioactive compounds and eating. Part I: A systematic review in humans

The taste of food plays a crucial role in determining what and how much we eat. Thus, interventions that temporarily block sweet taste receptors offer a promising approach to addressing unhealthy behaviours associated with sugary foods. However, the relationship between reduced sweet taste response and food consumption remains unclear, with contradictory findings. Certain studies suggest that a diminished perception of sweetness leads to a sense of fullness and results in reduced food intake, while others suggest the opposite effect. To shed some light, our systematic review looked into the relationship between diminished sweet taste response and food consumption by examining the effects of bioactive compounds that experimentally inhibit sweetness in healthy individuals. This review was registered in the International Prospective Register of Systematic Reviews and conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Scottish Intercollegiate Guidelines Network, and covered original papers included in Web of Science, PubMed, Scopus, Food Science Source and Food Science and technology abstracts. We identified 33 peer-reviewed English-language studies that fit the topic and met the inclusion criteria. The current literature predominantly focuses on the immediate impact of oral gymnemic acids, failing to provide preliminary evidence in support of the specific threshold hypothesis, above which food consumption decreases and below which the opposite effect occurs. Additionally, there was inconsistency in the findings regarding the short-term desire to eat following sweetness inhibition. Considering the downstream effects on energy intake and their clinical applications, further research is needed to clarify both the acute within-session effects (i.e., not wanting any more now) and the longer-term effects (i.e., deciding not to start eating) linked to oral sweet-taste-suppressing compounds.

A Comparative Analysis of the Incidence, Severity and Duration of Smell and Taste Loss in COVID-19 Cases Versus Non-COVID-19 Cases: A Longitudinal Cohort Study

The COVID-19 pandemic has highlighted the relevance of olfactory and gustatory disorders. However, these symptoms can also be caused by various other factors. In this study we aimed to compare the incidence, severity and duration between COVID-19 related and non-COVID-19 related smell and taste disorders. We conducted a longitudinal cohort study using data from the Dutch biobank Lifelines, which includes over 167,000 participants. The data were collected using 27 questionnaires distributed between March 2020 and May 2022. Descriptive data and the incidence of smell and taste loss in both groups were calculated. To visualize the proportion of severity rates of symptoms, a heatmap was created. A survival analysis was conducted and presented in a reversed Kaplan-Meier curve to show the probability of having persistent smell loss in both groups. The study included 235,722 participants. The incidence of smell loss was higher in the COVID-19 positive group, when compared to the COVID-19 negative group. We found varying degrees of symptom severity in COVID-19 positive cases, ranging from mild to severe, while non-COVID-19 related cases mostly reported mild symptoms. The survival outcome for smell and taste loss was 0.12 (SE 0.03, 95% CI 0.07-0.21) in COVID-19 related cases, and was 0.17 (SE 0.03, 95% CI 0.12-0.24) in cases related to other causes. This study reveals a higher incidence and severity of smell and taste loss in individuals with COVID-19 compared to non-COVID-19 related cases. However, non-COVID-19 related smell and taste loss tend to have a longer duration.

More spice, less salt: how capsaicin affects liking for and perceived saltiness of foods in people with smell loss

People who lose their sense of smell self-report consuming more salt to compensate for a lack of flavor and enhance eating enjoyment. However, this can contribute to excess sodium intake and a poor diet. Capsaicin may help increase salt taste intensity and eating enjoyment in this population, but this has not been studied. The purpose of this study was to determine 1) whether salt intake in those with smell loss differs from population averages, 2) whether capsaicin increases flavor and salt taste intensity, and 3) if adding spice to foods increases food liking in individuals with smell loss. Participants 18-65 years old with confirmed partial or total smell loss for at least 12 weeks completed two sets of replicate test sessions (four total). In two sessions participants rated overall flavor intensity, taste qualities' intensities, spicy intensity, and liking for model tomato soups with low or regular sodium content and three levels of capsaicin (none, low, or moderate). In the other two sessions, participants rated the same sensory attributes for model food samples with three levels of added spice (none, low, or moderate). 24-hour urine samples were also collected to determine sodium intake. Results indicate that although sodium intake is higher than recommended in those with smell loss (2893 ± 258 mg/day), they do not consume more sodium than population averages. Adding low and moderate amounts of capsaicin to a model tomato soup increased the intensity of overall flavor and saltiness compared to a model tomato soup without capsaicin. However, the effect of capsaicin on liking differed by food type. In conclusion, the addition of capsaicin can improve flavor, salt taste intensity, and eating enjoyment in people with smell loss.

A Simple Taste Test for Clinical Assessment of Taste and Oral Somatosensory Function-The "Seven-iTT"

Taste dysfunctions may occur, for example, after viral infection, surgery, medications, or with age. In clinical practice, it is important to assess patients' taste function with rapidity and reliability. This study aimed to develop a test that assesses human gustatory sensitivity together with somatosensory functions of astringency and spiciness. A total of 154 healthy subjects and 51 patients with chemosensory dysfunction rated their gustatory sensitivity. They underwent a whole-mouth identification test of 12 filter-paper strips impregnated with low and high concentrations of sweet, sour, salty, bitter (sucrose, citric acid, NaCl, quinine), astringency (tannin), and spiciness (capsaicin). The percentage of correct identifications for high-concentrated sweet and sour, and for low-concentrated salty, bitter and spicy was lower in patients as compared with healthy participants. Interestingly, a lower identification in patients for both astringent concentrations was found. Based on the results, we proposed the Seven-iTT to assess chemo/somatosensory function, with a cut-off of 6 out of 7. The test score discriminated patients from healthy controls and showed gender differences among healthy controls. This quantitative test seems to be suitable for routine clinical assessment of gustatory and trigeminal function. It also provides new evidence on the mutual interaction between the two sensory systems.

Subgroups in the treatment of nasal polyposis with dupilumab: A retrospective study

Dupilumab has been shown to be safe and effective in treating chronic rhinosinusitis with polyposis (CRSwNP). There is to this date no published data whether subgroups like patients with aspirin exacerbated respiratory disease (AERD), increased histologic eosinophilia or elevated blood eosinophil or IgE-levels benefit greater from dupilumab therapy. Moreover, there is no data comparing the efficacy of functional endoscopic sinus surgery (FESS) with dupilumab therapy. We conducted a retrospective chart review of all patients that were treated at a tertiary referral center for CRswNP with dupilumab. We also contacted the patients with a questionnaire to evaluate the efficacy of previous surgeries and dupilumab therapy by visual analogue scale (VAS) and the glasgow benefit inventory (GBI) as well as report on side effects. Overall, 75 patients were included in the study at hand that reported back 138 times. While dupilumab treatment was efficient, we found no systematic evidence of greater efficacy of dupilumab in patients with AERD, histologic eosinophilia or increased blood eosinophil or IgE-levels. All patients showed a considerable decrease in subjective burden of disease, objective smell tests and endoscopic findings. From the patients point of view, dupilumab therapy showed greater efficacy both in the VAS and the GBI overall and all subcategories but "social support." Dupilumab is efficient in treating CRSwNP; this effect is independent from disease characteristics like AERD, histologic eosinophilia, serum IgE-levels or eosinophil counts. There seems to be a group of patients that benefit greater from dupilumab therapy compared to FESS.

Well-being in patients with olfactory dysfunction

This cross-sectional, retrospective study aimed to investigate the differences in well-being among patients with olfactory disorder (OD) with quantitative and/or qualitative olfactory dysfunctions, and to identify factors associated with well-being (WB). We included 470 OD patients. WB (WHO-5 questionnaire), quantitative olfactory function (Sniffin' Sticks) and qualitative dysfunction were assessed. Overall, 35% of the OD patients reported a poor WB, higher than 22% of the normative data in general population. For quantitative function, anosmia patients showed lower WB scores than hyposmia and normosmia patients (all p's < 0.03). For qualitative dysfunction, patients with severe parosmia showed lower WB scores than patients without and with less severe parosmia (p's < 0.01). Regarding OD causes in hyposmic patients, post-infectious patients showed poorer WB than idiopathic patients (p = 0.01); sinonasal patients had lower WB than post-traumatic and idiopathic patients (all p's < 0.04). There was a weak but significant positive correlation between WB score and Threshold test score (r = 0.11, p = 0.02). Hierarchical regression analyses showed that women gender, Threshold and overall Sniffin' Sticks scores (TDI) significantly predicted WB score in OD patients. Our results implied that quantitative and qualitative dysfunction is associated with WB. However, only patients with severe dysfunction showed significantly lower WB. While this needs to be better understood, in order to improve well-being, in these patients it appears to be highly important to improve olfactory function, and here especially olfactory sensitivity.

Body Fat Moderates the Association of Olfactory Dysfunction with Dietary Intake in U.S. Middle-Aged and Older Adults: A Cross-Sectional Analysis of NHANES 2013-2014

Background: Obesity relates to impaired olfactory function. Abnormal olfactory function is also associated with poor diet; however, whether obesity-related markers shape this relationship is unknown. Methods: Cross-sectional analysis (n = 1415, age > 40 years) of NHANES 2013−2014 examined body fat percent (BF%) and waist circumference (WC) as moderators of the relationship between olfactory function and diet. The olfactory function test identified adults with olfactory dysfunction (OD) or normal olfaction (NO). Validated 24 h recall captured nutrient intake and Healthy Eating Index-2010 scores. BF% and WC were measured. We tested adjusted linear regression models, with an interaction term between olfactory function and BF%/WC, for each nutrient or HEI score, and reported coefficients (β), standard errors (SE), and p-values for significant interaction terms. Results: In OD (9.5%; mean age 50.9 years, 95% CI 49.6, 52.2) compared with NO (mean age 49.3 years, 95% CI 48.8, 49.9), higher BF% was associated with higher intake of saturated fat (β (SE): 0.2 (0.1) g; p = 0.06) and percent of total calories from total fat (0.2 (0.1); p = 0.07), saturated (0.1 (0.004); p = 0.02), and monounsaturated fat (0.1 (0.1); p = 0.08); lower percent of total calories from carbohydrates (−0.2 (0.1); p = 0.09) and mg of sodium (−17.8 (09.6); p = 0.08); and a higher (healthier) refined grain score (0.1 (0.1); p = 0.04). Higher WC was associated with higher refined grain scores (0.01 (0.02); p = 0.01) in OD. Conclusion: BF% may shape dietary intake and quality in OD. Longitudinal studies are needed to elucidate the directionality of these relationships and develop strategies to improve dietary intake among OD.

Psychophysical chemosensory dysfunction in eating disorders: a qualitative systematic review

PURPOSE

Patients with chemosensory dysfunction experience significant quality of life disruptions, including reduced enjoyment of eating. While chemosensory dysfunction has been associated with eating disorders, the relationship is poorly understood. This systematic review aims to characterize psychophysical gustation and olfaction in patients with eating disorders.

METHODS

Systematic review of investigations assessing psychophysical chemosensory function in patients with organic eating disorders.

RESULTS

26 studies were included. Five studies assessed both chemosenses, while 12 and 9 assessed exclusively gustation or olfaction, respectively. In total, 779 patients were included [72.4% anorexia nervosa (AN), 26.7% bulimia nervosa (BN), 0.8% combined AN/BN]. Patients with eating disorders experienced rates of hypogeusia up to 87% in AN and 84.6% in BN. There was evidence for alterations in psychophysical olfaction, but orientation of trends were less clear. Chemosensory dysfunction was more evident in AN patients. Treatment correlated with improved chemosensory function.

CONCLUSIONS

Despite heterogeneity in study methodology and results, this review demonstrates that patients with eating disorders experience some degree of chemosensory dysfunction, particularly in gustation. This symptomatology overlaps with those experienced by patients with other causes of chemosensory impairment. These findings suggest potential broad psychosocial, dietary, and mental health implications in patient populations experiencing chemosensory dysfunction.

LEVEL OF EVIDENCE

Level II.

Subjective Mouthfeel and Temperature Alterations in COVID-19 Patients Six to Ten Months After Diagnosis

Introduction

The characteristics and impact of mouthfeel, temperature, smell, and taste alterations in patients with COVID-19 at a long term are yet not well known. In this study, these characteristics and their impact on daily life and quality of life (QoL) were assessed, six to ten months after infection, in patients with COVID-19 searching for peer support on Facebook.

Methods

Between December 2020 and January 2021, members of two COVID-19 Facebook groups were invited to complete a questionnaire. Participants were asked to report their perception of mouthfeel, temperature, smell, and taste alterations and their impact.

Results

The questionnaire was completed by 157/216 respondents (73%), with 92% being women. Alterations in mouthfeel, temperature, smell, and taste were reported by respectively 66, 40, 148, and 133 participants. The most frequently reported mouthfeel alterations were "a different feeling" and "dry mouth" in 38 and 30 participants, respectively. Preferences for food temperature were equally changed to "freezing", "cool", "room temperature", "a bit warmer", and "warmer". An impact on daily life and QoL was reported by most patients with alterations in mouthfeel (91% and 79%), temperature (78% and 60%), smell (98% and 93%), and taste (93% and 88%), respectively.

Conclusions

Patients with COVID-19 searching for peer support on Facebook experienced, next to smell and taste alterations, mouthfeel and temperature disturbances, six to ten months after infection. These alterations have an impact on daily life and QoL.

Implications

Health professionals should, next to smell and taste alterations, be aware of mouthfeel and temperature alterations in patients with COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12078-022-09304-y.

Predictive usefulness of RT-PCR testing in different patterns of Covid-19 symptomatology: analysis of a French cohort of 12,810 outpatients

Reverse transcriptase polymerase chain reaction (RT-PCR) is a key tool to diagnose Covid-19. Yet it may not be the most efficient test in all patients. In this paper, we develop a clinical strategy for prescribing RT-PCR to patients based on data from COVIDOM, a French cohort of 54,000 patients with clinically suspected Covid-19, including 12,810 patients tested by RT-PCR. We use a machine-learning algorithm (decision tree) in order to predict RT-PCR results based on the clinical presentation. We show that symptoms alone are sufficient to predict RT-PCR outcome with a mean average precision of 86%. We identify combinations of symptoms that are predictive of RT-PCR positivity (90% for anosmia/ageusia) or negativity (only 30% of RT-PCR+ for a subgroup with cardiopulmonary symptoms): in both cases, RT-PCR provides little added diagnostic value. We propose a prescribing strategy based on clinical presentation that can improve the global efficiency of RT-PCR testing.

A study of depression, partnership and sexual satisfaction in patients with post-traumatic olfactory disorders

Post-traumatic olfactory dysfunction (PTOD) is associated with a significant decrease in quality of life. The present study aimed to explore whether PTOD is associated with depression and changes in sexuality. There were two groups in this case-control study. The patient group consisted of patients with PTOD (n = 55), and the control group comprised healthy individuals without the olfactory disorder (n = 115). Olfactory function, depression, partnership, and sexual satisfaction were assessed using the Iranian version of the Sniffin' Sticks test (Ir-SST), Beck Depression Inventory (BDI), Enrich Couple Scale (ECS) and Sexual Satisfaction Scale for Women (SSSW). The BDI scores were higher in the patient group than in the control group (p < 0.001). The SSSW score was lower in the patient group than in controls (p < 0.01), although the ECS score was not significantly different between patients and controls. Also, there was no significant difference in the severity of trauma between marital satisfaction and sexual satisfaction. However, the analysis showed a statistically significant difference in depression scores in connection with the head trauma severity. In the PTOD group, depression was increased and sexual satisfaction declined. Understanding the association of olfactory dysfunction with depression and sexuality allows patients and doctors to deal with less notable consequences of this disorder.

Development of a questionnaire to investigate socio-cultural differences in the perception of smell, taste and flavour

Objectives

Clinical experience and daily life indicate that the importance of smell, taste and flavour is variable among individuals. Therefore, the aim of this research was to develop a questionnaire to investigate the importance attributed to smell, taste and flavour and socio-cultural differences among individuals.

Methods

Cross-cultural adaptation of the questionnaire was executed by two professional translators and one bilingual investigator and pre-tested on a pilot group of 25 subjects with normal smell and taste abilities. The final version of the questionnaire was sent by e-mail to 850 healthy subjects. The Google form consisted of three parts: "The importance of olfaction" developed by Croy et al. in 2010, "The importance of taste and flavour" developed by our team and a section to collect demographic data. The questions were classified into "association", "application", "consequence" and "aggravation". Statistical differences were assessed using t-test with p ≤ 0.05. Correlations were calculated using Spearman's test. Internal consistency was assessed using the Cronbach's Alpha, while test-retest reliability was analysed by calculating the Intraclass Correlation Coefficients (ICC2k).

Results

The questionnaire received a non-response rate of 10.7%. Calculation of Cronbach's alpha showed good internal reliability (a = 0.87). Test-retest evaluation was satisfactory for all subscales, with an overall ICC2k = 0.84 (CI 0.79-0.89). Statistical analysis showed that smell, taste and flavour appeared to be more important for women when compared to men (p < 0.001). No statistical differences were seen between individuals with various educational background (p > 0.05), and the importance of smell (r = 0.16; p < 0.01), taste and flavour (r = 0.08; p < 0.05) did not decline with age.

Conclusions

The development of this original test provides an overview into the importance of smell, taste and flavour among individuals. Although further research is needed, it can help in the evaluation and investigation of aspects that influence people to seek medical attention in the presence of sensory alterations.

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.

Food-related oral discomfort: A cross-sectional survey assessing the sensory dimension of oral discomfort in French independently living adults

BACKGROUND

Discomfort encountered during oral processing may cause food avoidance and increase the risk of malnutrition in older adults. The aim of the present survey was to explore the relationships between oral health and the oral discomfort experienced while eating in senior people.

MATERIALS AND METHODS

In a cross-sectional study, oral discomfort was assessed in a sample of 119 independently living participants aged between 35 and 81 years. Statistical analyses were used to identify categorical variables associated with food-related oral discomfort, including age, oral health-related quality of life (OHQoL), saliva secretion, occluding support, oral diseases and denture use.

RESULTS

Food-related oral discomfort concerned 28.5% of the participants. Within the sample study, the risk of experiencing food-related oral discomfort was increased for participants perceiving average (OR = 7.968, CI 95% = 2.603-24.381, p = .000) or poor OHQoL (OR = 17.109, CI 95% = 4.398-66.552, p = .000) and presenting strictly fewer than 7 occlusal functional units (OFUs) (OR = 3.396, CI 95% = 1.206-9.561, p = .020). Textured foods including fibrous (66.6%), heterogenous (60.6%) and grainy foods (42.4%) were mostly cited as food-related oral discomfort trigger factors. Within the 66-80 years group, participants having 0-6 OFUs were four times more likely to experience oral discomfort related to fibrous foods than participants having more than 7 OFUs (OR = 4.812, CI 95% = 1.192-19.415, p = .024). Within this group, participants having their teeth replaced by denture were also four times more likely to develop oral discomfort related to foods with heterogeneous textures (OR = 4.714, CI 95% = 1.030-21.562, p = .045) and grainy foods (OR = 7.285, CI 95% = 1.308-40.568, p = .023) than non-denture wearers.

CONCLUSION

Poor oral health conditions may generate oral discomfort with foods in the elderly especially with fibrous, heterogenous and grainy textures, and thus affect mealtime experience.

Reduced sexual motivation of diabetic female rats: Restoration with insulin

The aim of this study was to evaluate female rat sexual motivation in a model of diabetes mellitus type 1. Severe hyperglycemia was induced in ovariectomized Wistar rats by injecting streptozotocin [STZ, 100 mg/kg, i.p.]. Ten days later, females received estradiol benzoate (10 μg/rat, s.c.) plus progesterone (3 mg/rat, s.c.). A group of STZ-treated animals was administered with insulin (2-4 U) every 12 h for 10 days, which normalized glucose levels. In the partner preference (PP) and sexual incentive motivation (SIM) tests, control females spent more time close to a sexually experienced male (SE) than with a castrated male (CM). STZ-treated females stayed the same amount of time with both stimuli, that is, they lost their sexual preference. We also evaluated the sense of smell using two behavioral tests, one related to sexual odors (SO) and another one to food odors (FO). In the SO test, control females spent more time sniffing the sawdust coming from cages that contained SE males; hyperglycemic females remained the same amount of time sniffing the sawdust of both stimuli: SE and CM. In the FO test, no differences were found between control and STZ-treated groups. Insulin treatment reverted the changes observed in hyperglycemic females in the PP, SIM and SO tests. These data suggest that severe hyperglycemia decreases sexual motivation and that insulin recovers such diminution.

Smell, taste and trigeminal disorders in a 65-year-old population

BACKGROUND

Smell, taste and trigeminal disorders likely have a substantial impact on human daily life. However, data regarding the prevalence of these disorders in Norway are scarce. The aim of this study was to investigate the prevalence of smell, taste, trigeminal disorders and associated factors in a 65-year-old population in Oslo, Norway.

METHODS

A random sample of 223 individuals (123 men, 100 women) participated in the study. Medical history was obtained, and unstimulated whole saliva (UWS) and stimulated whole saliva (SWS) were collected to determine salivary secretion rates. Sniffin`n Sticks and Taste Strips (Burghart Messtechnik GmbH, Wedel, Germany) were used for quantitative testing of olfactory and gustatory function. In addition, the participants' self-reported perceptions of smell and taste, and burning mouth sensation were investigated.

RESULTS

The results showed that 34 % of the participants had reduced smell (28 % hyposmia and 6 % anosmia) and 28 % had reduced taste perception (21 % hypogeusia and 7 % ageusia). 13 % of the partcipants had a combination of smell and taste disorders. Dysgeusia was reported by 5 % and burning mouth sensation (syndrome) by 3 % of the participants. Hyposmia, hypogeusia and ageusia were significantly more prevalent among men. Significant associations were found between taste disorders and previous history of cerebral hemorrhage and heart attack, and between burning mouth sensation and gastrointestinal disorders. Disturbances in olfactory, gustatory and trigeminal function were significantly related to medication use. Ageusia and burning mouth sensation were significantly more prevalent among smokers. Except from higher prevalence of ageusia among participants with hyposalivation with respect to SWS, no significant associations were found between salivary secretion rate and chemosensory or trigeminal disorders in the present study.

CONCLUSIONS

The present study revealed that one-third of 65-year-old individuals had impaired smell and more than one-fourth had impaired taste function. The prevalence of dysgeusia and burning mouth sensation was very low. Reduced smell and taste perception were more common among men than women. Furthermore, some diseases and medications were associated with chemosensory and trigeminal disorders. Ageusia was associated with SWS hyposalivation.

A Detailed Characterisation of Appetite, Sensory Perceptional, and Eating-Behavioural Effects of COVID-19: Self-Reports from the Acute and Post-Acute Phase of Disease

Sensory perception alterations are common in relation to COVID-19 disease, but less is known about the characteristic of the sensory alterations, and how they associate with alterations in appetite and eating behaviour. The current study aims to investigate the acute and long-term effects of COVID-19 disease on (1) the desire for food, hunger, and satiety sensations; (2) smell, taste, and flavour perception; (3) meals and intake of food types; and (4) the frequency of commonly applied strategies to tackle potential changes in appetite and sensory perception. An online survey was conducted among Danish adults (n = 102) who had experienced changes in appetite, sensory perception, and/or food-related pleasure due to COVID-19 disease. Key results include appetite-altering effects at all times during the day when suffering from COVID-19 and often associated with impaired sensory function. Severe sensory perception alterations were found, namely, for the perception of taste, ageusia > hypogeusia > hypergeusia, and for the perception of smell, anosmia > parosmia > hyposmia > hyperosmia. Eating behavioural changes included alteration in quantitative and qualitative aspects of intake. The effects were, in general, more pronounced during the acute phase of disease than during the post-acute phase. The findings illustrate the complexity by which COVID-19 affects human appetite, sensory perception, and eating behaviour, but also point to strategies to cope with these changes.

Symptoms of Depression in Patients with Chemosensory Disorders

INTRODUCTION

Patients with chemosensory dysfunction frequently report symptoms of depression. The current study aims to clarify whether the type (smell dysfunction, taste dysfunction, and mixed smell and taste dysfunction), severity, duration, or cause of dysfunction have differential impacts on the symptoms of depression.

METHODS

899 patients with chemosensory disorders and 62 controls were included. Following a structured interview and an otorhinolaryngological examination, subjects underwent olfactory tests (Sniffin' Sticks), gustatory tests (taste sprays) and an assessment of depressive symptoms (Beck Depression Inventory). Information on the cause and duration of disorders was also collected.

RESULTS

Patients with combined olfactory/gustatory dysfunction had higher depression scores than patients with smell dysfunction only and controls, and no significant difference was found between the smell dysfunction and controls. Anosmia patients, but not hyposmia patients, exhibited higher depression scores than controls. Among various causes of chemosensory disorders, patients from the posttraumatic group had higher depression scores than patients with other causes of chemosensory dysfunction (sinonasal, idiopathic, or postinfectious). Multiple linear regression analyses suggested that reduced olfactory function was associated with enhanced depression scores in the olfactory disorders group (B = -0.326, t = -2.294, and p = 0.02) and in all patients with chemosensory disorders (B = -0.374, t = -2.550, p = 0.017).

DISCUSSION/CONCLUSION

Simultaneously decreased input of olfaction and gustation seems to have an additive effect on the exacerbation of emotional dysfunction. Early intervention should be considered for depression symptoms in patients with mixed olfactory/gustatory dysfunction in clinical practice.

Older People's Experiences of Living with, Responding to and Managing Sensory Loss

(1) Background: Ageing is associated with a decline in sensory function (sight, hearing, taste, touch and smell), which play an important role in the maintenance of an older person’s health, independence and well-being. (2) Methods: This qualitative study obtained data through face-to-face semi-structured interviews with a convenience sample of thirteen community-dwelling adults 65 years and older. Themes were derived inductively, guided by semi-structured interviews. (3) Results: Twelve participants had two or more sensory impairments, mainly concurrent hearing and vision, which became apparent when a situation/individual alerted them to change/s occurring. They were less aware of impaired smell, taste and touch. Sensory changes impacted on important life functions, prompting many participants to take measured risks in maintaining their independence. Half (seven) of the participants lacked motivation to manage sensory function through goal-directed behaviour, taking remedial actions only when this was relevant to lifestyle preferences. (4) Conclusions: Internal and/or external triggers of sensory changes did not generally motivate remedial action. Health professionals can help to improve older people’s attention to sensory impairment by routinely discussing sensory function with them, screening for sensory changes and facilitating early intervention and support.

Possibilities for Maintaining Appetite in Recovering COVID-19 Patients

COVID-19 and sequelae thereof are known to cause chemosensory dysfunction, posing a risk for intake and adequate nutrition for recovery. The overall objective of this study was to investigate the subjective strategies for maintaining appetite applied by patients recovering from COVID-19. The study included 19 in-depth interviews, focusing on patients suffering from long-term effects of COVID-19. The results were analysed using a thematic analysis for qualitative data. Results on strategies for maintaining appetite included four key themes: (1) a focus on well-functioning senses, (2) a focus on familiar foods, (3) a focus on the eating environment, and (4) a focus on post-ingestive well-being. It was found that factors prior to, during and after food intake, as well as the context, could influence desire to eat and pleasure related to food intake. As ageusia and anosmia make characterization of food difficult, being able to recognize and memorize its flavour was important to engage in consumption. Under normal circumstances, the hedonic value of food relies predominantly on the flavour of foods. When suffering from chemosensory dysfunction, shifting focus towards the texture of food, including trigeminal stimulation during consumption, were beneficial for maintaining appetite and food-related pleasure. Furthermore, a focus on the holistic satisfying feelings of choosing healthy food, as well as a focus on other people’s enjoyment during meals were reported to boost well-being around food intake. The study elaborated our understanding of the complex consequences of COVID-19, and can be applied in health promoting initiatives targeted patients recovering from COVID-19.

The Aetiology of Olfactory Dysfunction and Its Relationship to Diet Quality

People with olfactory loss may choose foods rich in sugar, salt and fat to compensate their loss—foods that constitute a Western-style diet (WSD). However, olfactory dysfunction has not been consistently linked to any particular type of dietary change. Here we considered whether the aetiology of olfactory dysfunction may affect consumption of a WSD. Two-hundred and twenty-two people with olfactory dysfunction of varying cause, were tested for chemosensory performance and their frequency of consumption of a WSD. There was no evidence of a link between a WSD and olfactory dysfunction at the aggregate level, but an aetiology-based approach revealed various patterns, showing both positive and negative associations between olfactory performance and consumption of a WSD. We suggest a number of reasons why, in certain cases, greater olfactory dysfunction may be linked to lower intakes of a WSD, and the role that different aetiologies may have in affecting choices for foods that may appeal following olfactory impairment.

Oral health-related quality of life and associated factors in patients with burning mouth syndrome

OBJECTIVE

The purpose of this study was to assess oral health-related quality of life (OHRQoL) in patients with burning mouth syndrome (BMS) and to identify clinical factors associated with OHRQoL.

METHODS

Fifty-seven patients with BMS (56.4 ± 10.7 years) participated in the study. Patients underwent oral examination, laboratory tests, psychological evaluation, measurement of salivary flow rates and evaluation of clinical characteristics using a BMS questionnaire. The OHRQoL of patients was assessed using the Oral Health Impact Profile-14 (OHIP-14).

RESULTS

The OHIP-14 score for patients with BMS was 38.6 ± 12.8. Patients had higher scores for the psychological discomfort and physical pain dimensions of the OHIP-14. The intensity of taste disturbance or xerostomia symptoms (β = 0.464, P < .001), worry about symptoms (β = 0.307, P = .020), and results of psychological evaluation (β = 0.311, P = .026) were significantly associated with OHIP-14 score. Multiple linear regression showed that the intensity of taste disturbance or xerostomia symptoms was significantly associated with decreased OHRQoL (β = 0.637, P = .026).

CONCLUSIONS

This study suggests that severity of taste disturbance or xerostomia is an important factor that influences OHRQoL in patients with BMS.

Taste disorder's management: a systematic review

BACKGROUND

Taste disorder is a frequent drug-induced or disease-related oral trouble. Various pharmacological, surgical, or physical treatments have previously been proposed for taste function recovery.

OBJECTIVES

The aim of the present systematic review was to assess the effects of palliative and curative interventions on taste recovery in light of recent literature.

MATERIALS AND METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, a search of the literature published up to June 2019 was conducted using MEDLINE via PubMed, EMBASE, and The US National Institutes of Health Trials Register (PROSPERO registration reference: CRD 42019139315). The methodological quality of the included trials was rated with the "Delphi list For Quality Assessment of Randomized Clinical Trials" and the Newcastle-Ottawa scale.

RESULTS

From the 1842 titles first identified, 28 articles met the inclusion criteria. Interventions included zinc (aspartate, sulfate, gluconate, acetate, picolinate, and Polaprezinc®), esomeprazole, L-thyroxin, bethanechol, oral glutamine, delta-9-tetrahydrocannabinol, alpha-lipoic acid, Ginkgo biloba, artificial saliva, pilocarpine, local anesthesia, and improved oral hygiene. The quality of evidence ranged from poor to high.

CONCLUSION

Improving oral hygiene may promote taste ability. Zinc may prevent and alleviate taste disorder in patients undergoing head and neck radiotherapy.

CLINICAL RELEVANCE

The systematic review provided evidence about the clinical efficacy of oral procedures, zinc supplementation, and palliative cares in dysgeusic patients. Further research is needed to find effective treatments with low adverse effects.

Zika virus infection in chemosensory cells

Zika virus (ZIKV) is an emerging virus belonging to the genus Flavivirus. ZIKV infection is a significant health concern, with increasing numbers of reports of microcephaly cases in fetuses and Guillain-Barré syndrome (GBS) in adults. Interestingly, chemosensory disturbances are also reported as one of the manifestations of GBS. ZIKV infects several human tissues and cell types in vitro and in vivo. However, there is no study demonstrating ZIKV infection and replication in chemosensory cells, including olfactory and taste cells. Taste papilla and olfactory cells are chemosensory receptor cells with unique histological, molecular, and physiological characteristics. Here we examined ZIKV infection (PRVABC59) in cultured human olfactory epithelial cells (hOECs) and fungiform taste papilla (HBO) cells in vitro, as well as in vivo mouse taste and olfactory epithelial and olfactory bulb tissues. Interestingly, while HBO cells showed resistance to ZIKV replication, hOECs were highly susceptible for ZIKV infection and replication. Further, we demonstrated the presence of ZIKV particles and expression of viral proteins in olfactory epithelium, as well as in olfactory bulb, but not in taste papillae, of immunocompromised mice (ifnar^/-) infected with the PRVABC59 strain of ZIKV. These observations suggest that chemosensory cells in the olfactory neuroepithelium and olfactory bulb may be important tissues for ZIKV replication and dissemination.

Olfactory Sensitivity Is Related to Erectile Function in Adult Males

Background

The olfactory system influences human social behavior, in particular the selection of a spouse. However, there is currently a lack of clinical research on the relationship between the olfactory system and erectile dysfunction (ED) in adult males.

Aim

We explored the association between olfactory sensitivity and erectile function and its possible mechanisms.

Results

A total of 574 patients, adult males aged between 19 and 42 years, diagnosed with ED in the Department of Infertility and Sexual Medicine of the Third Affiliated Hospital of Sun Yat-sen University from 2015 to 2018 were analyzed retrospectively. Among them, 115 patients (20.03%) had rhinologic diseases (RDs). In addition, in 201 adult male patients who underwent nasal surgery in the ENT department from 2012 to 2016, including 29 (14.43%) with ED, nasal congestion, nasal discharge, and hyposmia were the most common complaints based on the numerical rating scale (NRS). Furthermore, a prospective study was performed in a total of 102 sequential outpatients (male adults) with RD only (n = 46), ED only (n = 42) and both RD and ED (n = 14) in 2019, together with 40 healthy (male adults) volunteers as controls. The results showed that ED patients with RD had severe nasal discomfort and decreased erectile function (P < 0.0001). The olfactory sensitivity of patients with ED was lower than that of the controls, and patients with both ED and RD had the worst olfactory sensitivity (P < 0.0001). Spearman correlation analyses showed that sense of smell was positively correlated with the International Index of Erectile Function-5 score (R = 0.507, P ≤ 0.0001) and the Erection Hardness Scale score (R = 0.341, P < 0.0001). Logistic regression analyses showed that having an olfactory disorder (OD), RD, age, and visual analog scale (VAS, over 5) score were risk factors for ED outcome, indicating that OD patients had a 16.479-fold increased risk for an ED outcome (P < 0.05).

Conclusion

A significant correlation was detected between olfactory sensitivity and erectile function in adult males. In particularly, impairment of olfactory sensitivity is more common in patients with both ED and RD than in patients suffering from a single disease.

Sensory Profile of Adults with Reduced Food Intake and the Potential Roles of Nutrition and Physical Activity Interventions

The sensory profile, referring to sight, smell, taste, hearing, and touch, plays an essential role in optimizing the habitual intake of energy and macronutrients. However, specific populations, such as older adults, are known to have impaired energy intake. In this paper, the relevance of sensory impairments in this older population is described, and the extent to which nutritional and physical activity interventions can modulate these sensory responses when food intake is insufficient is explored. With aging, all senses deteriorate, and in most cases, such deteriorations diminish the nutritional response. The only exception is sight, for which both positive and negative impacts on nutritional response have been reported. From a prevention perspective, nutritional interventions have been understudied, and to date, only hearing is known to be positively affected by a good nutritional profile. In comparison, physical activity has been more frequently studied in this context, and is linked to an improved preservation of 4 senses. Regarding treatment, very few studies have directly targeted sensory training, and the focus of research has tended to be on nutrition and physical activity intervention. Sensory training, and nutritional and physical activity treatments all have beneficial effects on the senses. In the future, researchers should focus on exploring gaps in the literature specifically concerning prevention, treatment, and sensory response to understand how to improve the efficacy of current approaches. In order to maintain sensory acuity and recover from sensory impairment, the current state of knowledge supports the importance of improving nutritional habits as well as physical activity early on in life. A combined approach, linking a detailed lifestyle profile with the assessment of numerous senses and one or more interventional approaches (nutrition, physical activity, sensory training, etc.), would be required to identify effective strategies to improve the nutritional state of older individuals.

Smell and 3D Haptic Representation: A Common Pathway to Understand Brain Dynamics in a Cross-Modal Task. A Pilot OERP and fNIRS Study

Cross-modal perception allows olfactory information to integrate with other sensory modalities. Olfactory representations are processed by multisensory cortical pathways, where the aspects related to the haptic sensations are integrated. This complex reality allows the development of an integrated perception, where olfactory aspects compete with haptic and/or trigeminal activations. It is assumed that this integration involves both perceptive electrophysiological and metabolic/hemodynamic aspects, but there are no studies evaluating these activations in parallel. The aim of this study was to investigate brain dynamics during a cross-modal olfactory and haptic attention task, preceded by an exploratory session. The assessment of cross-modal dynamics was conducted through simultaneous electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) recording, evaluating both electrophysiological and hemodynamic activities. The study consisted of two experimental sessions and was conducted with a sample of ten healthy subjects (mean age 25 ± 5.2 years). In Session 1, the subjects were trained to manipulate 3D haptic models (HC) and to smell different scents (SC). In Session 2, the subjects were tested during an attentive olfactory task, in order to investigate the olfactory event-related potentials (OERP) N1 and late positive component (LPC), and EEG rhythms associated with fNIRS components (oxy-Hb and deoxy-Hb). The main results of this study highlighted, in Task 1, a higher fNIRS oxy-Hb response during SC and a positive correlation with the delta rhythm in the central and parietal EEG region of interest. In Session 2, the N1 OERP highlighted a greater amplitude in SC. A negative correlation was found in HC for the deoxy-Hb parietal with frontal and central N1, and for the oxy-Hb frontal with N1 in the frontal, central and parietal regions of interests (ROIs). A negative correlation was found in parietal LPC amplitude with central deoxy-Hb. The data suggest that cross-modal valence modifies the attentional olfactory response and that the dorsal cortical/metabolic pathways are involved in these responses. This can be considered as an important starting point for understanding integrated cognition, as the subject could perceive in an ecological context.

Impaired eating-related quality of life in chronic rhinosinusitis

BACKGROUND

Despite the tremendous burden of smell and taste dysfunction in patients with chronic rhinosinusitis (CRS), objective measures of smell and taste fail to fully account for eating-related disruptions in CRS patient quality of life (QOL). In this study we sought to investigate the driving force behind impaired eating-related QOL in CRS patients.

METHODS

Adult CRS patients were prospectively enrolled and answered a series of surveys relating to smell, taste, overall sinus-specific QOL, and depression. Patients with both smell-related and taste-related eating complaints were considered to have impaired eating-related QOL. Clinical demographics, objective chemosensory scores, and endoscopy scores were collected.

RESULTS

Seventy patients were enrolled and 23% showed impaired eating-related QOL. In multivariable analyses, patients with aspirin-exacerbated respiratory disease (AERD) showed 10.7 times higher odds of impaired eating-related QOL (odds ratio [OR] 10.72; 95% confidence interval [CI], 1.09 to 105.09; p = 0.042); meanwhile, for every 1-point increase in depression scores, the odds of impaired eating-related QOL increased by 1.3 (OR 1.31; 95% CI, 1.10 to 1.57; p = 0.003). For every 1-point decrease in orthonasal olfactory threshold, the odds of impaired eating-related QOL increased by 1.9 times (OR 1.85; 95% CI, 1.14 to 3.00; p = 0.013). Symptom scores, polyp status, endoscopic scores, and other olfactory measures did not remain significant after adjusting for other variables in forward-selection multivariable modeling.

CONCLUSION

Disruptions in eating-related QOL cannot be fully explained by objective smell or taste testing alone. We identified AERD and depression as independent risk factors for greater odds of impaired eating-related QOL in CRS. Improved orthonasal threshold scores were independently associated with better eating-related QOL.

Factor analysis of the questionnaire of olfactory disorders in patients with chronic rhinosinusitis

BACKGROUND

Olfactory-specific quality of life (QOL) can be measured using the Questionnaire of Olfactory Disorders-Negative Statements (QOD-NS), which examines various aspects of olfactory dysfunction. It is unknown if certain factors of the QOD-NS differentially impact QOL.

METHODS

Patients with chronic rhinosinusitis (CRS) completed the QOD-NS, 22-item Sino-Nasal Outcome Test (SNOT-22), Medical Outcomes Study Short Form 6-D (SF-6D) health utility measure, and Patient Health Questionnaire-2 (PHQ-2) depression screen. Exploratory factor analysis of the QOD-NS was performed. Associations between QOD-NS factors and other QOL metrics were analyzed before and after endoscopic sinus surgery (ESS).

RESULTS

Outcomes were examined on 132 patients. The QOD-NS contains 4 distinct factors. There was no difference in associations between the different factors and baseline clinical characteristics. ESS had greatest effect size (d) on factors 2 and 4 (d = 0.29 and 0.27, respectively, p < 0.05). Postsurgical changes in the SF-6D and SNOT-22 had the strongest correlation with factor 2 scores (r = 0.29 and 0.34, respectively, p < 0.05), and changes in the PHQ-2 had the strongest correlation to factor 3 (r = 0.24, p < 0.05). Abnormal QOD-NS scores at baseline were associated with effect size increases of 50% to 100% (p < 0.05).

CONCLUSION

The QOD-NS measures 4 distinct factors. Eating-related questions had the greatest improvement after ESS. Health utility and CRS-specific QOL improvement most strongly associated with factor 2, while PHQ-2 changes are most highly associated with factor 3, suggesting a differential impact of the factors of the QOD-NS on varying aspects of QOL.

Olfactory Function Relates to Sexual Experience in Adults

The olfactory system contributes significantly to human social behavior and especially to mate choice and empathic functioning. In this context, previous research examining individuals with impaired olfactory function indicated an influence of the sense of smell on different aspects of sexuality. However, the applied samples, methods, and results are diverse and an involvement of confounding factors, such as breathing problems, depression or social insecurity cannot be ruled out. The present study examined the potential correlation between odor threshold in healthy participants and their sexual desire, sexual experience, and sexual performance. In 70 adults (28 male, 42 female; mean age 24.8 ± 4.1 years), odor threshold was assessed using the "Sniffin' Sticks." The participants also responded to a battery of questions on sexual desire (Sexual Desire Inventory), sexual experience (orgasm frequency, perceived pleasantness of sexual activities on a visual analogue scale) as well as sexual performance (frequency of having sex, average duration of sexual intercourse). Odor sensitivity correlated positively with sexual experience: Participants with high olfactory sensitivity reported higher pleasantness of sexual activities. Further, women with high olfactory sensitivity reported a higher frequency of orgasms during sexual intercourse. These findings were exclusively present for sexual experience; no significant correlations were detected for sexual desire or sexual performance. The experience of sexual interactions appears to be enriched by olfactory input. We discuss that the perception of certain body odors may contribute to the concept of sexual pleasure by enhanced recruitment of reward areas.

Testicular cancer patients undergoing cisplatin based chemotherapy exhibit temporary olfactory threshold scores changes

Testicular cancer is the most frequent malignant disease in young males between 15 and 35 years. Platinum based chemotherapy regimen is the therapy of choice in advanced disease. This treatment has also adverse effects caused by the cytostatic active substances, such as olfactory dysfunctions. The aim of this study was, therefore, to monitor olfactory function of testicular cancer patients during and 6 months after chemotherapy. A total of 17 patients (mean age 31.06 ± 10.26 years), which underwent chemotherapy (mean 2.47 cycles ± 0.5) were enrolled in this study. Odor threshold, discrimination and identification were assessed by means of the "Sniffin' Sticks" prior to and on day 42, 90 and 180 after chemotherapy has been completed. Furthermore, patients' ratings of olfactory function and depressive symptoms were evaluated. Threshold scores were significantly lower on day 90 (8.0 ± 2.51) compared to baseline (10.4 ± 2.20) (p = 0.014) and recovered almost completely on day 180 (9.65 ± 3.26). Odor discrimination and identification did not show significant changes during therapy. The decrease of the olfactory function during/immediately after chemotherapy was underlined by the subjectively perceived impaired olfactory function during this time. In addition almost every fourth patient presented with a depressed mood at the beginning of chemotherapy. Patients should be informed about possible transient olfactory impairment during/immediately after chemotherapy.

Contraceptive Use Affects Overall Olfactory Performance: Investigation of Estradiol Dosage and Duration of Intake

The influence of female sex steroids on cognitive performance and sensory perception has been investigated for decades. However, previous research that studied olfaction revealed inconsistent results. The main aim of this study was to investigate the effects of different ethinyl estradiol (EE) concentrations of oral contraceptives and duration of intake on olfactory function. Forty-two healthy women, with regular intake of either high or low EE dosage over at least one year and up to 15 years participated in this study. Results revealed a significant concordance between a priori categorization in the two groups with high and low EE dosage and data-driven hierarchical clustering (p = 0.008). Furthermore, significantly higher olfactory performance was observed in women using low-dose products compared to women using high-dosed products (p = 0.019). These findings indicate different effects of pill use with regard to EE concentration. We therefore strongly recommend the acquisition of information about EE dosage of oral contraceptives to reduce potential confounding factors when investigating sensory systems.

Brain lesion-pattern analysis in patients with olfactory dysfunctions following head trauma

The presence of cerebral lesions in patients with neurosensory alterations provides a unique window into brain function. Using a fuzzy logic based combination of morphological information about 27 olfactory-eloquent brain regions acquired with four different brain imaging techniques, patterns of brain damage were analyzed in 127 patients who displayed anosmia, i.e., complete loss of the sense of smell (n = 81), or other and mechanistically still incompletely understood olfactory dysfunctions including parosmia, i.e., distorted perceptions of olfactory stimuli (n = 50), or phantosmia, i.e., olfactory hallucinations (n = 22). A higher prevalence of parosmia, and as a tendency also phantosmia, was observed in subjects with medium overall brain damage. Further analysis showed a lower frequency of lesions in the right temporal lobe in patients with parosmia than in patients without parosmia. This negative direction of the differences was unique for parosmia. In anosmia, and also in phantosmia, lesions were more frequent in patients displaying the respective symptoms than in those without these dysfunctions. In anosmic patients, lesions in the right olfactory bulb region were much more frequent than in patients with preserved sense of smell, whereas a higher frequency of carriers of lesions in the left frontal lobe was observed for phantosmia. We conclude that anosmia, and phantosmia, are the result of lost function in relevant brain areas whereas parosmia is more complex, requiring damaged and intact brain regions at the same time.

Olfaction in chemotherapy for head and neck malignancies

OBJECTIVE

Systemic chemotherapy for different malignancies occurs alongside various side effects, including reduced sensory function. To date, little is known about the effect of chemotherapeutic agents on olfaction. The aim of this study was to provide new data about changes in sense of smell during chemotherapy among patients with advanced squamous cell carcinomas of the head and neck region.

METHODS

In a prospective, controlled cohort study of patients undergoing up to three courses of chemotherapy (cis- or carboplatin, 5-fluorouracil and docetaxel), olfaction was evaluated prior to and directly following completing a cycle, as well as 3 weeks later with the beginning of the next cycle. For evaluation of sense of smell, the established Sniffin' Sticks test with a determination of threshold, discrimination and identification (TDI) was used. Thirty-three patients (44-85 years old, 25 men and 8 women) were included in the study. Most malignancies were located in the oropharynx.

RESULTS

Among the 28 patients who scored normosmic or hyposmic at the beginning of the study, the mean decrease in TDI-score was 0.72 points (24.0-23.2) in the first cycle, 2.1 points (24.5-22.4) in the second cycle and 0.77 points (24.2-23.4) in the third cycle. The decrease during the second cycle was significant. Age (>55 years) had a significant (negative) influence in the first and the second cycles. Smoking only showed a tendency to decreased TDI-scores in chemotherapy. In-between consecutive cycles an increase in TDI-score was obvious (+1.0 points after the first and +1.5 points after the second cycle).

CONCLUSION

Chemotherapy with cisplatin, 5-fluorouracil and docetaxel significantly affected sense of smell to a small extent. This effect was more pronounced in elderly patients and smokers. This fact must be taken into account as a possible additional negative effect in usually prevailing malnutrition in these patients. Furthermore, no cumulative effect of the administered therapeutic agents on olfaction could be proven during this study and recovery occurred within a 3-week period.

Olfactory drug effects approached from human-derived data

The complexity of the sense of smell makes adverse olfactory effects of drugs highly likely, which can impact a patient's quality of life. Here, we present a bioinformatics approach that identifies drugs with potential olfactory effects by connecting drug target expression patterns in human olfactory tissue with drug-related information and the underlying molecular drug targets taken from publically available databases. We identified 71 drugs with listed olfactory effects and 147 different targets. Taking the target-based approach further, we found additional drugs with potential olfactory effects, including 152 different substances interacting with genes expressed in the human olfactory bulb. Our proposed bioinformatics approach provides plausible hypotheses about mechanistic drug effects for drug discovery and repurposing and, thus, would be appropriate for use during drug development.