Long-Term Taste and Smell Outcomes After COVID-19.

Importance: Self-report surveys suggest that long-lasting taste deficits may occur after SARS-CoV-2 infection, influencing nutrition, safety, and quality of life. However, self-reports of taste dysfunction are inaccurate, commonly reflecting deficits due to olfactory not taste system pathology; hence, quantitative testing is needed to verify the association of post-COVID-19 condition with taste function. Objective: To use well-validated self-administered psychophysical tests to investigate the association of COVID-19 with long-term outcomes in taste and smell function. Design, Setting, and Participants: This nationwide cross-sectional study included individuals with and without a prior history of COVID-19 recruited from February 2020 to August 2023 from a social media website (Reddit) and bulletin board advertisements. In the COVID-19 cohort, there was a mean of 395 days (95% CI, 363-425 days) between diagnosis and testing. Exposure: History of COVID-19. Main Outcomes and Measures: The 53-item Waterless Empirical Taste Test (WETT) and 40-item University of Pennsylvania Smell Identification Test (UPSIT) were used to assess taste and smell function. Total WETT and UPSIT scores and WETT subtest scores of sucrose, citric acid, sodium chloride, caffeine, and monosodium glutamate were assessed for groups with and without a COVID-19 history. The association of COVID-19 with taste and smell outcomes was assessed using analysis of covariance, χ2, and Fisher exact probability tests. Results: Tests were completed by 340 individuals with prior COVID-19 (128 males [37.6%] and 212 females [62.4%]; mean [SD] age, 39.04 [14.35] years) and 434 individuals with no such history (154 males [35.5%] and 280 females [64.5%]; mean (SD) age, 39.99 [15.61] years). Taste scores did not differ between individuals with and without previous COVID-19 (total WETT age- and sex-adjusted mean score, 33.41 [95% CI, 32.37-34.45] vs 33.46 [95% CI, 32.54-34.38]; P = .94). In contrast, UPSIT scores were lower in the group with previous COVID-19 than the group without previous COVID-19 (mean score, 34.39 [95% CI, 33.86-34.92] vs 35.86 [95% CI, 35.39-36.33]; P < .001]); 103 individuals with prior COVID-19 (30.3%) and 91 individuals without prior COVID-19 (21.0%) had some degree of dysfunction (odds ratio, 1.64 [95% CI, 1.18-2.27]). The SARS-CoV-2 variant present at the time of infection was associated with smell outcomes; individuals with original untyped and Alpha variant infections exhibited more loss than those with other variant infections; for example, total to severe loss occurred in 10 of 42 individuals with Alpha variant infections (23.8%) and 7 of 52 individuals with original variant infections (13.5%) compared with 12 of 434 individuals with no COVID-19 history (2.8%) (P < .001 for all). Conclusions and Relevance: In this study, taste dysfunction as measured objectively was absent 1 year after exposure to COVID-19 while some smell loss remained in nearly one-third of individuals with this exposure, likely explaining taste complaints of many individuals with post-COVID-19 condition. Infection with earlier untyped and Alpha variants was associated with the greatest degree of smell loss.

Taste and smell function in Wilson's disease.

OBJECTIVE: Wilson's disease (WD) is a metabolic disorder associated with abnormal copper metabolism that results in hepatic, psychiatric, and neurologic symptoms. No investigation of taste function has been made in patients with WD, although olfactory dysfunction has been evaluated. METHODS: Quantitative taste and smell test scores of 29 WD patients were compared to those of 790 healthy controls. Taste was measured using the 53-item Waterless Empirical Taste Test (WETT®) and smell using the 40-item revised University of Pennsylvania Smell Identification Test (R-UPSIT®). Multiple linear regression analysis controlled for age and sex. RESULTS: Average WETT® scores did not differ meaningfully between WD and control subjects (respective medians & IQRs = 32 [28-42] & 34 [27-41]); linear regression coefficient = 1.19, 95% CI [-0.81, 3.19], p = 0.242). In contrast, WD was associated with significantly reduced olfactory function [respective median (IQR) R-UPSIT® scores = 35 (33-37) vs. 37 (35-38); adjusted linear regression coefficient = -1.59, 95% CI [-2.34, -0.833]; p < 0.001)]. Neither olfaction nor taste were influenced by WD symptom subtype [23 (79.3%) were hepatic-predominant; 6 (20.7%) neurologic predominant]; R-UPSIT®, p = 0.774; WETT®, p = 0.912). No effects of primary medication or years since diagnosis (R-UPSIT®, p = 0.147; WETT®, p = 0.935) were found. Weak correlations were present between R-UPSIT® and WETT® scores for both control (r=0.187, p < 0.0001) and WD (r=0.237) subjects, although the latter correlation did not reach the 0.05 α level (p = 0.084). CONCLUSION: Although WD negatively impacts smell function, taste is spared. Research is needed to understand the pathophysiologic mechanisms responsible for this divergence.

Development of parallel forms of a brief smell identification test useful for longitudinal testing.

Although there are numerous brief odor identification tests available for quantifying the ability to smell, none are available in multiple parallel forms that can be longitudinally administered without potential confounding from knowledge of prior test items. Moreover, empirical algorithms for establishing optimal test lengths have not been generally applied. In this study, we employed and compared eight machine learning algorithms to develop a set of four brief parallel smell tests employing items from the University of Pennsylvania Smell Identification Test that optimally differentiated 100 COVID-19 patients from 132 healthy controls. Among the algorithms, linear discriminant analysis (LDA) achieved the best overall performance. The minimum number of odorant test items needed to differentiate smell loss accurately was identified as eight. We validated the sensitivity of the four developed tests, whose means and variances did not differ from one another (Bradley-Blackwood test), by sequential testing an independent group of 32 subjects that included persons with smell dysfunction not due to COVID-19. These eight-item tests clearly differentiated the olfactory compromised subjects from normosmics, with areas under the ROC curve ranging from 0.79 to 0.83. Each test was correlated with the overall UPSIT scores from which they were derived. These brief smell tests can be used separately or sequentially over multiple days in a variety of contexts where longitudinal olfactory testing is needed.

SARS-CoV-2 infection and long COVID among California farmworkers.

PURPOSE: The purpose of this cross-sectional study was to determine the prevalence of long COVID and identify its clinical manifestations among farmworkers in California. METHODS: We collected data on sociodemographic characteristics, anthropometrics, clinical chemistries and anti-SARS-CoV-2 immunoglobulin G antibodies, self-reported SARS-CoV-2 infection history, and standardized health tests and scales from 297 farmworkers in California between February and July 2022. RESULTS: Most participants were born in Mexico or Central America, had less than a high school diploma, and were overweight or obese. The prevalence of long COVID (defined as self-reported SARS-CoV-2 infection with symptoms >28 days) among farmworkers with a suspected or test-confirmed infection was 61.8%. Participants with long COVID had higher mean [95% CI] body mass index (32.9 [31.6-34.1]) and high-sensitivity C-reactive protein levels (4.8 [3.7, 6.0]) than those with no COVID-19 history (30.5 [29.3-31.7], and 3.3 [2.2, 4.3], respectively). Farmworkers with long COVID also reported greater fatigue, dyspnea, taste and smell problems, and overall poorer mental and physical health, than those with no COVID-19 history. Farmworkers with long COVID had increased odds of functional limitations compared to those with a self-reported SARS-CoV-2 infection with symptoms ≤28 days (OR [95% CI]: 7.46 [3.26, 17.09]). CONCLUSIONS: A significant proportion of farmworkers experience long COVID with persistent symptoms that limit their ability to perform their work. A comprehensive approach that addresses the unique needs and challenges of farmworkers is warranted given this population's high prevalence of long COVID and the essential nature of their work.

The 8-item NHANES pocket smell test®: Normative data.

This study provides normative data useful for interpreting scores from the Pocket Smell Test® (PST®), a brief "scratch & sniff" neuropsychological olfactory screening test comprised of 8 items from the 40-item University of Pennsylvania Smell Identification Test (UPSIT®). We combined 3,485 PST® scores from the 2013 to 2014 National Health and Nutrition Survey (NHANES) of persons 40 years of age and older with equivalent PST® items extracted from an UPSIT® database of 3,900 persons ranging in age from 5 to 99 years. Decade-related age- and gender-adjusted percentile normative data were established across the entire age spectrum. Cut-points for defining clinically useful categories of anosmia, probable microsmia, and normosmia were determined using receiver operating characteristic (ROC) curve analyses. An age-related decline in test scores was evident for both sexes after the age of 40 years, with women outperforming men. Based on the ROC analyses, subjects scoring 3 or less (AUC = 0.81) defines anosmia. Regardless of sex, a score of 7 or 8 on the N-PST® signifies normal function (AUC of 0.71). Probable microsmia is classified as scores extending from 3 to 6. These data provide an accurate means for interpreting PST® scores within a number of clinical and applied settings.

Establishment of a consensus protocol to explore the brain pathobiome in patients with mild cognitive impairment and Alzheimer's disease: Research outline and call for collaboration.

Microbial infections of the brain can lead to dementia, and for many decades microbial infections have been implicated in Alzheimer's disease (AD) pathology. However, a causal role for infection in AD remains contentious, and the lack of standardized detection methodologies has led to inconsistent detection/identification of microbes in AD brains. There is a need for a consensus methodology; the Alzheimer's Pathobiome Initiative aims to perform comparative molecular analyses of microbes in post mortem brains versus cerebrospinal fluid, blood, olfactory neuroepithelium, oral/nasopharyngeal tissue, bronchoalveolar, urinary, and gut/stool samples. Diverse extraction methodologies, polymerase chain reaction and sequencing techniques, and bioinformatic tools will be evaluated, in addition to direct microbial culture and metabolomic techniques. The goal is to provide a roadmap for detecting infectious agents in patients with mild cognitive impairment or AD. Positive findings would then prompt tailoring of antimicrobial treatments that might attenuate or remit mounting clinical deficits in a subset of patients.

The Olfactory Dysfunction of COVID-19.

Until the coronavirus disease 2019 (COVID-19) pandemic, much of the scientific community and the general public lacked an appreciation of the impact of decreased smell function on everyday life, including the importance of this sensory system for safety, nutrition, and overall quality of life. It is now well established that the SARS-CoV-2 virus inflicts measurable but frequently reversible smell loss during its acute phase. Indeed, in many studies such loss is the most common symptom of COVID-19. Permanent or long-term deficits (i.e., deficits lasting over a year) may occur in up to 30% of those who have been infected, including the development of odor distortions (dysosmias; parosmias). This review presents up-to-date information on the epidemiology, severity, and pathophysiology of COVID-19-related smell dysfunction, including its association with psychological and neurological sequelae.

High prevalence of olfactory dysfunction detected in treatment-naive patients with head and neck cancer.

BACKGROUND: Previous studies demonstrated the difficulty of patients with Head and Neck Cancer (HNC) in sensing food taste, a function in which olfaction has a significant role. However, neither study employed psychophysical tests or control groups to establish the veracity of such complaints. AIMS/OBJECTIVES: In this study, we quantitatively tested the olfactory function of HNC individuals and compared their function to that of healthy controls. METHODS: Thirty-one HNC naïve treatment patients and thirty-one controls, matched for sex, age, schooling, and smoking, were tested with the University of Pennsylvania Smell Identification Test (UPSIT). RESULTS: The olfactory function was significantly worse among the patients diagnosed with head and neck cancer [UPSIT cancer = 22.9(CI 95%: 20.5-25.4) vs. UPSIT controls = 29.1(CI 95%: 26.9-31.3); p < .001]. Most patients with HNC had olfactory disorders (n = 29, 93.5%). The risk of olfactory loss was higher in the cancer group [OR: 10.5(CI 95%: 2.1-51.9; p = .001)]. CONCLUSION AND SIGNIFICANCE: Olfactory disorders can be detected in more than 90% of patients with head and neck cancer when evaluated using a well-validated olfactory test. Smell disorders may be a potential marker for early diagnosis of HNC.

Electrogustometry: validation of bipolar electrode stimulation.

Electrogustometry (EGM) is a practical way to test taste. It is typically performed using unipolar electrodes, with the anode on the tongue and the cathode on the hand, forearm, or neck. This results in electric current passing through nontaste tissues and adds a level of impracticality to its clinical application. We compared, using a repeated measures counterbalanced design, anodal thresholds from a unipolar electrode to those of a unique bipolar electrode in which the anode and cathode are contiguously located. Both sides of the anterior tongue were assessed in 70 subjects, as were the effects of age and sex. Nonparametric analyses were performed. The median threshold of the bipolar electrode's central disk (2.49 µA) did not differ from that of the unipolar electrode (2.96 µA) (P = 0.84). On average, older persons exhibited higher thresholds. No significant sex or tongue side effects were evident. Interestingly, when the annular (donut-shaped) bipolar electrode served as the anode, the threshold was higher than that of the other electrodes (5.19 µA; Ps < 0.001). This conceivably reflected lessened summation of activity among adjacent afferents and partial sampling of tongue regions with fewer taste buds. Correlations among all EGM thresholds were nominally higher for women than for men, ranging from 0.83 to 0.85 for women and 0.54 to 0.67 for men; all Ps < 0.001. This study validates the use of a bipolar electrode for assessing taste function, averting movement of current through nontaste-related tissues and making such testing safer and more practical.

Chemosensory Dysfunction 3-Months After COVID-19, Medications and Factors Associated with Complete Recovery.

OBJECTIVES: To examine the longitudinal prevalence and recovery of olfactory, gustatory, and oral chemesthetic deficits in a sizable cohort of SARS-CoV-2 infected persons using quantitative testing. To determine whether demographic and clinical factors, mainly the medications used after the COVID-19 diagnosis, influence the test measures. METHODS: Prospective cohort in a hospital with primary, secondary, tertiary, and quaternary care. Patients with confirmed COVID-19 were tested during the acute infection phase (within 15 days of initial symptom, n = 187) and one (n = 113) and 3 months later (n = 73). The University of Pennsylvania Smell Identification Test, the Global Gustatory Test, and a novel test for chemesthesis were administered at all visits. RESULTS: During the acute phase, 93% were anosmic or microsmic and 29.4% were hypogeusic. No one was ageusic. A deficit in oral chemesthesis was present in 13.4%. By 3 months, taste and chemesthesis had largely recovered, however, some degree of olfactory dysfunction remained in 54.8%. Remarkably, patients who had been treated with anticoagulants tended to have more olfactory improvement. Recovery was greater in men than in women, but was unrelated to disease severity, smoking behavior, or the use of various medications prior to, or during, COVID-19 infection. CONCLUSIONS: When using quantitative testing, olfactory disturbances were found in nearly all SARS-CoV-2 infected patients during the acute infection phase. Taste or chemesthetic deficits were low. Olfactory impairment persisted to some degree in over half of the patients at the 3-month follow-up evaluation, being more common in women and less common in those who had been treated earlier with anticoagulants. LEVEL OF EVIDENCE: 3.

Examining the Influence of Chemosensation on Laryngeal Health and Disorders.

Inhaled airborne stimuli are associated with laryngeal disorders affecting respiration. Clinically, several themes emerged from the literature that point to specific gaps in the understanding and management of these disorders. There is wide variation in the types of airborne stimuli that trigger symptoms, lack of standardization in provocation challenge testing using airborne stimuli, and vague reporting of laryngeal symptoms. Scientifically, evidence exists outside the field of voice science that could prove useful to implement among patients with impaired laryngeal-respiration. To expand this area of expertise, here we provide a thematic overview of relevant evidence and methodological tools from the discipline of chemosensory sciences. This review provides distinctions across the three chemosensory systems of olfaction, trigeminal chemesthesis, and gustation, guidance on selecting and delivering common chemosensory stimuli for clinical testing, and methods of quantifying sensory experiences using principles of human psychophysics. Investigating the science of chemosensation reveals that laryngeal responses to inhaled airborne stimuli have explanations involving physiological mechanisms as well as higher cognitive processing. Fortunately, these findings are consistent with current pharmacological and nonpharmacological interventions for impaired laryngeal-respiration. Based on the close relationships among inhaled airborne stimuli, respiration, and laryngeal function, we propose that new perspectives from chemosensory sciences offer opportunities to improve patient care and target areas of future research.

Alzheimer and Parkinson diseases, frontotemporal lobar degeneration and amyotrophic lateral sclerosis overlapping neuropathology start in the first two decades of life in pollution exposed urbanites and brain ultrafine particulate matter and industrial nanoparticles, including Fe, Ti, Al, V, Ni, Hg, Co, Cu, Zn, Ag, Pt, Ce, La, Pr and W are key players. Metropolitan Mexico City health crisis is in progress.

The neuropathological hallmarks of Alzheimer's disease (AD), Parkinson's disease (PD), frontotemporal lobar degeneration (FTLD), and amyotrophic lateral sclerosis (ALS) are present in urban children exposed to fine particulate matter (PM2.5), combustion and friction ultrafine PM (UFPM), and industrial nanoparticles (NPs). Metropolitan Mexico City (MMC) forensic autopsies strongly suggest that anthropogenic UFPM and industrial NPs reach the brain through the nasal/olfactory, lung, gastrointestinal tract, skin, and placental barriers. Diesel-heavy unregulated vehicles are a key UFPM source for 21.8 million MMC residents. We found that hyperphosphorylated tau, beta amyloid1-42, α-synuclein, and TAR DNA-binding protein-43 were associated with NPs in 186 forensic autopsies (mean age 27.45 ± 11.89 years). The neurovascular unit is an early NPs anatomical target, and the first two decades of life are critical: 100% of 57 children aged 14.8 ± 5.2 years had AD pathology; 25 (43.9%) AD+TDP-43; 11 (19.3%) AD + PD + TDP-43; and 2 (3.56%) AD +PD. Fe, Ti, Hg, Ni, Co, Cu, Zn, Cd, Al, Mg, Ag, Ce, La, Pr, W, Ca, Cl, K, Si, S, Na, and C NPs are seen in frontal and temporal lobes, olfactory bulb, caudate, substantia nigra, locus coeruleus, medulla, cerebellum, and/or motor cortical and spinal regions. Endothelial, neuronal, and glial damages are extensive, with NPs in mitochondria, rough endoplasmic reticulum, the Golgi apparatus, and lysosomes. Autophagy, cell and nuclear membrane damage, disruption of nuclear pores and heterochromatin, and cell death are present. Metals associated with abrasion and deterioration of automobile catalysts and electronic waste and rare earth elements, i.e., lanthanum, cerium, and praseodymium, are entering young brains. Exposure to environmental UFPM and industrial NPs in the first two decades of life are prime candidates for initiating the early stages of fatal neurodegenerative diseases. MMC children and young adults-surrogates for children in polluted areas around the world-exhibit early AD, PD, FTLD, and ALS neuropathological hallmarks forecasting serious health, social, economic, academic, and judicial societal detrimental impact. Neurodegeneration prevention should be a public health priority as the problem of human exposure to particle pollution is solvable. We are knowledgeable of the main emission sources and the technological options to control them. What are we waiting for?

Adaptation of the Pediatric Smell WheelTM to evaluate olfactory function in Brazilian children

Abstract Objective: Olfaction influences nutrition, safety, and the cognitive development of children. Presently there are few olfactory tests for children, and normative reference values are generally lacking. In this study, we validate the Pediatric Smell WheelTM (PSW) to evaluate olfactory function in Brazilian children. Methods: We modified and validated the PSW, a test developed in the United States, for administration in Brazil, and established normative data for Brazilian children. The validation process consisted of five phases. First, we identified odorants familiar to Brazilian children. Second, we established the test-retest reliability of the Brazilian PSW test that employed these odorants. Third, we compared the test scores of healthy children to those microsmic from adenoid hypertrophy. Fourth, we examined the test's ability to detect improvement in olfactory function before and after adenoidectomy. Finally, we determined a normative 10th percentile cut point for defining microsmia in a sample of 169 healthy Brazilian children between 5 and 12 years of age. Results: Eleven odors were identified for inclusion in the test. The test-retest reliability was modest (r = 0.54, p < 0.001), although likely attenuated based on the inclusion of only data from children with normal function. The test clearly differentiated the olfactory function of children with adenoid hypertrophy from that of healthy children and demonstrated the return of function after adenoidectomy. An overall score <7 was found useful in defining hyposmia, although additional age-related cut-points were also defined. Conclusion: A Brazilian version of the PSW was developed and validated and found to be efficacious in detecting smell dysfunction in children ranging in age from 5 to 12 years. Level of evidence: 1b (Diagnosis).

Biopsy of the olfactory epithelium from the superior nasal septum: is it possible to obtain neurons without damaging olfaction? / Biópsia do epitélio olfatório do septo nasal superior: é possível obter neurônios sem prejudicar o olfato?

Abstract Introduction Olfactory epithelium biopsy has been useful for studying diverse otorhinolaryngological and neurological diseases, including the potential to better understand the pathophysiology behind COVID-19 olfactory manifestations. However, the safety and efficacy of the technique for obtaining human olfactory epithelium are still not fully established. Objective This study aimed to determine the safety and efficacy of harvesting olfactory epithelium cells, nerve bundles, and olfactory epithelium proper for morphological analysis from the superior nasal septum. Methods During nasal surgery, 22 individuals without olfactory complaints underwent olfactory epithelium biopsies from the superior nasal septum. The efficacy of obtaining olfactory epithelium, verification of intact olfactory epithelium and the presence of nerve bundles in biopsies were assessed using immunofluorescence. Safety for the olfactory function was tested psychophysically using both unilateral and bilateral tests before and 1 month after the operative procedure. Results Olfactory epithelium was found in 59.1% of the subjects. Of the samples, 50% were of the quality necessary for morphological characterization and 90.9% had nerve bundles. There was no difference in the psychophysical scores obtained in the bilateral olfactory test (University of Pennsylvania Smell Identification Test [UPSIT®]) between means before biopsy: 32.3 vs. postoperative: 32.5, p= 0.81. Also, no significant decrease occurred in unilateral testing (mean unilateral test scores 6 vs. 6.2, p= 0.46). None out of the 56 different odorant identification significantly diminished (p> 0.05). Conclusion The technique depicted for olfactory epithelium biopsy is highly effective in obtaining neuronal olfactory tissue, but it has moderate efficacy in achieving samples useful for morphological analysis. Olfactory sensitivity remained intact.

Resumo Introdução A biópsia do epitélio olfatório tem sido útil para estudar diversas doenças otorrinolaringológicas e neurológicas, incluindo seu potencial para melhor compreender a fisiopatologia por trás das manifestações olfatórias na COVID‐19. No entanto, a segurança e eficácia da técnica de obtenção de epitélio olfatório humano ainda não estão totalmente estabelecidas. Objetivos Este estudo teve como objetivo determinar a segurança e eficácia da coleta de células do epitélio olfatório, feixes nervosos e epitélio olfatório adequados para análise morfológica, no septo nasal superior. Método Durante a cirurgia nasal, 22 indivíduos sem queixas olfatórias foram submetidos a biópsias de epitélio olfatório do septo nasal superior. A eficácia da obtenção de epitélio olfatório, a verificação de epitélio olfatório íntegro e a presença de feixes nervosos nas biópsias foram avaliadas por imunofluorescência. A segurança da função olfatória foi testada psicofisicamente usando testes unilaterais e bilaterais antes e um mês após o procedimento cirúrgico. Resultados Epitélio olfatório foi encontrado em 59,1% dos sujeitos. Das amostras, 50% apresentaram a qualidade necessária para a caracterização morfológica e 90,9% continham feixes nervosos. Não houve diferença nos escores psicofísicos obtidos no teste olfatório bilateral (University of Pennsylvania Smell Identification Test [UPSIT®]) entre as médias antes da biópsia: 32,3 vs. pós‐operatório: 32,5, p = 0,81. Além disso, nenhuma diminuição significante ocorreu no teste unilateral (escore médio do teste unilateral 6 vs. 6,2, p = 0,46). Não houve redução significante na identificação de nenhum dos 56 odorantes diferentes (p > 0,05). Conclusão A técnica descrita para biópsia de epitélio olfatório é altamente eficaz na obtenção de tecido olfatório neuronal, mas tem eficácia moderada na obtenção de amostras adequadas para análise morfológica. A capacidade olfativa permaneceu intacta.

Olfactory dysfunction in COVID-19: pathology and long-term implications for brain health.

Decreased smell function is related to brain health, future mortality, and quality of life. Most people inflicted with the SARS-CoV-2 virus evidence some measurable smell dysfunction during its acute phase, although many are unaware of the loss. Long-term deficits occur in up to 30% of COVID-19 cases, although total anosmia is relatively rare. This review explores what is presently known about the nature and pathophysiology of olfactory dysfunction due to the SARS-CoV-2 virus, including reversible inflammation within the olfactory cleft, downregulation of olfactory receptor proteins, and long-lasting peripheral and central damage to olfactory structures. It also addresses the question as to whether long-term smell loss might increase the likelihood of future development of cognitive and neurological deficits.

Comparison of Chinese and American subjects on the self-administered Waterless Empirical Taste Test.

Cultural differences have been reported between the taste sensitivity of persons of Asian and European ancestry, although findings have been mixed. This study sought to determine whether American and Chinese adults perform differently on a novel taste test that requires no water, can be self-administered, and employs a representative of umami as one of its tastants. This 53-trial test was administered to 113 Chinese and 214 Americans. The subjects orally sampled monomer cellulose pads containing one of four dried concentrations of sucrose, citric acid, NaCl, caffeine, and monosodium glutamate and indicated whether a sweet, sour, bitter, salty, brothy, or no taste sensation was perceived. Separate gender by culture analyses of covariance with age as the covariate were performed on the total score and the scores of each taste stimulus. For all taste qualities, women outperformed men and test scores declined with age. No difference between American and Chinese subjects was found for the total taste score (p = .129) or for the sucrose (p = .129) or NaCl (p = .368) scores. However, for monosodium glutamate, the scores were 28.40% higher for the Chinese than for the American subjects (p = .024), and for citric acid and caffeine, the scores were 24.12 and 21.79% higher for the American subjects (p's = .001 and .029). The basis for these differences is unclear, although both anatomical (e.g., differences in density or distribution of taste buds) and cultural factors may be involved. Future work is needed to determine the cause of these largely novel findings and whether they generalize to other Chinese and American samples. Practical applicationsIn this study, a practical self-administered quantitative taste test that requires no water was found to be sensitive to quality-specific differences in test scores between Chinese and American subjects, as well as to age and gender. The Chinese subjects outperformed the American subjects in correctly identifying the quality of monosodium glutamate (umami), whereas the American subjects outperformed Chinese subjects in correctly identifying the bitter and sour qualities of caffeine and citric acid, respectively. Experiential factors related to culture-specific cuisines may explain some of these differences. This research indicates that a relatively rapid taste test, which can be sent through the mail and which requires no test administrator or source of water, can be used in cross-cultural studies to elucidate individual differences in taste perception.

International consensus statement on allergy and rhinology: Olfaction.

BACKGROUND: The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O). METHODS: Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus. RESULTS: The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies. CONCLUSION: This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.

Prevalence of Prodromal Symptoms of Parkinson's Disease in the Late Middle-Aged Population.

BACKGROUND: The prodromal phase of Parkinson's disease (PD) can last up to 20 years and is characterized by a variety of non-motor symptoms. OBJECTIVE: To determine the prevalence of a selection of non-motor symptoms known to be associated with an increased risk of developing PD in a late middle-aged population-based sample and to determine their association with motor function. METHODS: At a mean age of 60.3 years, 775 subjects were recruited from the Longitudinal Aging Study Amsterdam (LASA). Hyposmia, cognitive impairment, patient-reported constipation, possible REM-sleep behavior disorder, depression, and anxiety were indexed as known PD risk factors. Additionally, 1) the PD screening questionnaire, 2) four physical performance tests, and 3) a functional limitations questionnaire, were used to determine whether the presence of two or more PD risk factors was associated with reduced motor function. RESULTS: The prevalence of single risk factors ranged between 3 and 13%. Approximately 11% of subjects had two or more PD risk factors. Motor functioning of subjects with two or more PD risk factors was significantly worse than performance of subjects without or with a single risk factor (all p values≤0.001). CONCLUSION: Approximately 11% of the late middle-aged population has two or more known PD risk factors. Among these subjects self-perceived PD symptoms and reduced physical performance are more prevalent, suggesting that at least some of these subjects may be in the prodromal phase of PD.

Biopsy of the olfactory epithelium from the superior nasal septum: is it possible to obtain neurons without damaging olfaction?

INTRODUCTION: Olfactory epithelium biopsy has been useful for studying diverse otorhinolaryngological and neurological diseases, including the potential to better understand the pathophysiology behind COVID-19 olfactory manifestations. However, the safety and efficacy of the technique for obtaining human olfactory epithelium are still not fully established. OBJECTIVE: This study aimed to determine the safety and efficacy of harvesting olfactory epithelium cells, nerve bundles, and olfactory epithelium proper for morphological analysis from the superior nasal septum. METHODS: During nasal surgery, 22 individuals without olfactory complaints underwent olfactory epithelium biopsies from the superior nasal septum. The efficacy of obtaining olfactory epithelium, verification of intact olfactory epithelium and the presence of nerve bundles in biopsies were assessed using immunofluorescence. Safety for the olfactory function was tested psychophysically using both unilateral and bilateral tests before and 1 month after the operative procedure. RESULTS: Olfactory epithelium was found in 59.1% of the subjects. Of the samples, 50% were of the quality necessary for morphological characterization and 90.9% had nerve bundles. There was no difference in the psychophysical scores obtained in the bilateral olfactory test (University of Pennsylvania Smell Identification Test [UPSIT®]) between means before biopsy: 32.3 vs. postoperative: 32.5, p = 0.81. Also, no significant decrease occurred in unilateral testing (mean unilateral test scores 6 vs. 6.2, p = 0.46). None out of the 56 different odorant identification significantly diminished (p > 0.05). CONCLUSION: The technique depicted for olfactory epithelium biopsy is highly effective in obtaining neuronal olfactory tissue, but it has moderate efficacy in achieving samples useful for morphological analysis. Olfactory sensitivity remained intact.

Adaptation of the Pediatric Smell WheelTM to evaluate olfactory function in Brazilian children.

OBJECTIVE: Olfaction influences nutrition, safety, and the cognitive development of children. Presently there are few olfactory tests for children, and normative reference values are generally lacking. In this study, we validate the Pediatric Smell WheelTM (PSW) to evaluate olfactory function in Brazilian children. METHODS: We modified and validated the PSW, a test developed in the United States, for administration in Brazil, and established normative data for Brazilian children. The validation process consisted of five phases. First, we identified odorants familiar to Brazilian children. Second, we established the test-retest reliability of the Brazilian PSW test that employed these odorants. Third, we compared the test scores of healthy children to those microsmic from adenoid hypertrophy. Fourth, we examined the test's ability to detect improvement in olfactory function before and after adenoidectomy. Finally, we determined a normative 10th percentile cut point for defining microsmia in a sample of 169 healthy Brazilian children between 5 and 12 years of age. RESULTS: Eleven odors were identified for inclusion in the test. The test-retest reliability was modest (r = 0.54, p < 0.001), although likely attenuated based on the inclusion of only data from children with normal function. The test clearly differentiated the olfactory function of children with adenoid hypertrophy from that of healthy children and demonstrated the return of function after adenoidectomy. An overall score <7 was found useful in defining hyposmia, although additional age-related cut-points were also defined. CONCLUSION: A Brazilian version of the PSW was developed and validated and found to be efficacious in detecting smell dysfunction in children ranging in age from 5 to 12 years. LEVEL OF EVIDENCE: 1b (Diagnosis).