Systematic Review of Dysgeusia Frequency Following Hematopoietic Stem Cell Transplant.

OBJECTIVES: In this systematic review, we aimed to shed light on the frequency of dysgeusia among patients who had received hematopoietic stem cell transplantation and to determine factors that may be conducive to this buccal symptom. MATERIALS AND METHODS: We conducted a systematic review of the literature on frequency of dysgeusia in patients who received hematopoietic stem cell transplant. We searched PubMed, PMC-PubMed, and Web of Science and followed the Preferred Reporting Items for Systematic reviews and Meta-analyses statement. RESULTS: We identified 15 studies. The global frequency of dysgeusia varied greatly, ranging from 16.7% to 95%. Allogeneic stem cell transplant, including cells from other individuals, had more secondary effects than autologous transplant. Rate of dysgeusia was higher at the beginning of treatment. We found some differences according to populations, with dysgeusia increasing with age. Pediatric patients recovered more quickly, perhaps as a result of their faster cell division and development of taste receptors. CONCLUSIONS: Dysgeusia can greatly affect quality of life during graft treatment. The frequency can vary according to a number of factors, which are different targets in treatment. Symptom management during transplant seems to contribute to overall improvement in treatment.

Time-frequency analysis of gustatory event related potentials (gERP) in taste disorders.

In taste disorders, the key to a correct diagnosis and an adequate treatment is an objective assessment. Compared to psychophysical tests, EEG-derived gustatory event-related potentials (gERP) could be used as a less biased measure. However, the responses identified using conventional time-domain averaging show a low signal-to-noise ratio. This study included 44 patients with dysgeusia and 59 healthy participants, who underwent a comprehensive clinical examination of gustatory function. gERPs were recorded in response to stimulation with two concentrations of salty solutions, which were applied with a high precision gustometer. Group differences were examined using gERP analyzed in the canonical time domain and with Time-Frequency Analyses (TFA). Dysgeusic patients showed significantly lower scores for gustatory chemical and electrical stimuli. gERPs failed to show significant differences in amplitudes or latencies between groups. However, TFA showed that gustatory activations were characterized by a stronger power in controls than in patients in the low frequencies (0.1-4 Hz), and a higher desynchronization in the alpha-band (8-12 Hz). Hence, gERPs reflect the altered taste sensation in patients with dysgeusia. TFA appears to enhance the signal-to-noise ratio commonly present when using conventional time-domain averaging, and might be of assistance for the diagnosis of dysgeusia.

Association of gustatory dysfunction and Alzheimer.

BACKGROUND: Chemosensory dysfunction has been reported to be involved in the pathogenesis of Alzheimer’s disease (AD). Compared with olfaction, gustatory dysfunction in AD has not been evaluated in depth. We reviewed previously published studies regarding gustatory dysfunction in patients with AD compared with healthy controls. METHODS: A systematic review was conducted by searching the MEDLINE, Cochrane Library, Embase, and PubMed databases covering publications from January 2000 to February 2023. The search was performed using the keyword "Alzheimer* AND (gustatory OR taste OR gustation)." Only studies that performed gustatory function testing and compared the results between patients with AD and healthy controls were included. A random-effects meta-analysis was performed. RESULTS: Twelve articles were finally included, and various gustatory tests including taste strips, the taste disk test, taste solutions, and subjective questionnaires were applied. Overall gustatory function based on the taste strip test was significantly decreased in patients with AD compared with controls in two out of three papers. The overall gustatory function of patients with AD was significantly decreased in all studies based on the taste disk and taste solution tests. We also found that the sweet taste test showed low heterogeneity across all the included studies, and there was low publication bias. In studies using subjective questionnaires, gustatory function was not significantly different between patients with AD and healthy controls in the meta-analysis. CONCLUSIONS: Based on these studies, gustatory dysfunction diagnosed by gustatory function testing was closely related to AD. However, the results of subjective questionnaires were not significantly different between patients with AD and healthy controls in the current meta-analysis. As the number of studies and enrolled subjects was limited and unified gustatory function testing was lacking, further studies are needed to confirm this relationship.

The relationship between loneliness, psychological resilience, quality of life and taste change in cancer patients receiving chemotherapy.

PURPOSE: This study aimed to determine the correlation between taste change, nutritional intake and quality of life in cancer patients receiving chemotherapy. A total of 610 (F = 314, M = 296) volunteers aged 19 and 65 who received outpatient chemotherapy treatment participated in the study. METHODS: Individuals' general information was obtained, anthropometric measurements were carried out, malnutrition status (Patient-Generated Subjective Global Assessment PG-SGA), loneliness (Cancer Loneliness Scale), psychological resilience (Psychological Resilience Scale), quality of life (Quality of Life Scale (EORT QLQ-C30) and taste changes were scrutinized [Chemotherapy-Induced Taste Alteration Scale (CiTAS)]. RESULTS: There was a negative correlation between the Cancer Loneliness Scale and PG-SGA and General Health Status (r = -0.494, p = 0.000; r = -0.406, p = 0.000) and a positive correlation with Symptom Scales (r = 0.484, p = 0.000; r = 0.506, p = 0.000) (p < 0.05). There was a positive correlation between the Psychological Resilience Scale and General Health Status (r = 0.393, P = 0.000), Functional Scales (r = 0.349, P = 0.000), and a negative correlation between Symptom Scales (r = -0.302, p = 0.000) (p < 0.05). 70.9% of men and 70.7% of women had severe malnutrition. General Taste Changes, General Health and Symptom Scale values were significant predictors of severe malnutrition status (p < 0.05). CONCLUSION: The symptoms that develop during the treatment process cause many psychological problems. Before starting treatment, patients should be evaluated comprehensively, depression anxiety levels and quality of life levels should be determined, and precautions should be taken accordingly.

Oral manifestations of COVID-19 in unvaccinated patients: a cross-sectional study.

BACKGROUND: Early studies have highlighted the possible development of dysgeusia and anosmia in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and these manifestations should be considered a potential indication of coronavirus disease 19 (COVID-19). As potential contributors to these symptoms, dentists should perform careful oral and oropharyngeal examinations and document suspicious oral lesions in patients with COVID-19, especially in those who complain of loss of taste and smell. The study's objective was to assess the prevalence of oral manifestations among ambulatory unvaccinated symptomatic patients with suspected COVID-19 during the acute phase of the disease. METHODS: This cross-sectional study evaluated oral manifestations in adults (aged ≥ 18 years) with suspected and confirmed SARS-CoV-2 infection. Chi-square and Fisher's exact tests were used to compare data between the groups (rRT-PCR-positive and rRT-PCR-negative patients). RESULTS: One hundred thirty-six participants were included. Most were female (n = 79; 58.1%), with a mean age of 39.53 (± 14.17) years. Of these, 54 (39.7%) had a positive rRT-PCR test, and 82 (60.3%) had negative rRT-PCR results. Oral manifestations were observed in 40 participants (74.1%) in the rRT-PCR-positive group and 67 participants (81.7%) in the rRT-PCR-negative group. The most common oral manifestations were xerostomia (n = 85; 62.5%) and dysgeusia/ageusia (n = 57; 41.9%). Different rates of gingivitis (n = 12; 22.2% vs. n = 5; 6.1%; p = 0.005) and halitosis (n = 7; 13.0% vs. n = 1; 1.2%; p = 0.007) were observed between the rRT-PCR-positive and -negative groups, respectively. Mouth ulcers, glossitis, tongue coating, and petechiae were reported in both groups without significant differences. CONCLUSIONS: A high prevalence of oral manifestations was observed in symptomatic patients with suspected or confirmed COVID-19. CLINICAL RELEVANCE: This study highlights the importance of routine oral examinations by dentists as part of the multidisciplinary care of COVID-19 patients.

Anosmia (smell failure) and dysgeusia (taste distortion) in COVID-19: it is genetic.

The COVID-19 pandemic is a very contagious respiratory illness with has affected millions of individuals worldwide. In addition to the well-known symptoms of any respiratory virus, COVID-19 can present with anosmia (failure to smell) and dysgeusia (distortion of the sense of taste). It appears to be a genetic link to the biological mechanisms underlying COVID-19-related anosmia and dysgeusia. Significant locus in the vicinity of the UGT2A1 and UGT2A2 genes are currently considered as the main culprit of the symptoms. However, more studies are needed to delineate a clear pathophysiology.Communicated by Ramaswamy H. Sarma.

Comparative Study of Chemosensory Dysfunction in COVID-19 in 2 Geographically Distinct Regions.

OBJECTIVE: To directly compare the prevalence of chemosensory dysfunction (smell and taste) in geographically distinct regions with the same questionnaires. METHODS: A cross-sectional study was performed to evaluate the self-reported symptoms among adults (older than 18 years) who underwent COVID-19 testing at an ambulatory assessment center in Canada and at a hospital in Israel between March 16, 2020, and August 19, 2020. The primary outcome was the prevalence of self-reported chemosensory dysfunction (anosmia/hypomsia and dysgeusia/ageusia). Subgroup analysis was performed to evaluate the prevalence of chemosensory deficits among the outpatients. RESULTS: We identified a total of 350 COVID-19-positive patients (138 Canadians and 212 Israelis). The overall prevalence of chemosensory dysfunction was 47.1%. There was a higher proportion of chemosensory deficits among Canadians compared to Israelis (66.7% vs 34.4%, P < .01). A subgroup analysis for outpatients (never hospitalized) still identified a higher prevalence of chemosensory dysfunction among Canadians compared to Israelis (68.2% vs 36.1%, P < 0.01). A majority of patients recovered their sense of smell after 4 weeks of symptom onset. CONCLUSION: Although the prevalence of chemosensory deficit in COVID-19 was found to be similar to previously published reports, the prevalence can vary significantly across different geographical regions. Therefore, it is important to obtain regionally specific data so that the symptom of anosmia/dysgeusia can be used as a guide for screening for the clinical diagnosis of COVID-19.

Lithium-Induced Dysgeusia and Hyposmia: A Case Report and a Literature Review.

BACKGROUND: Bipolar disorder is a complex psychiatric disorder where long-term treatment is crucial to maintain stabilization. Although largely well tolerated, lithium has a wide spectrum of adverse effects in different organs and seems to also cause taste and smell disorders, which remain rare and not largely described. We aim to present a rare case of hyposmia and dysgeusia secondary to lithium treatment in a bipolar patient and also conduct a review on these rare lithium adverse effects. CASE PRESENTATION: The case is a 43-year-old woman with type I bipolar disorder who became stabilized and fully functional with lithium therapy. After 4 months of treatment, she began to notice progressive hyposmia and dysgeusia. After multiple diagnostic and screening tests, lithium was implicated as the cause of the symptoms, which led to a switch to valproic acid. After 3 months, she was not compensated with valproic acid treatment, returned to lithium therapy despite its adverse effects, and became stabilized again. CONCLUSIONS: There are few data on lithium therapy taste and smell adverse effects. Most studies on this topic are likely to be case reports. Lithium therapy may cause dysgeusia and hyposmia, although mechanisms are not fully understood. These adverse effects can interfere negatively in patient's treatment adherence. Therefore, physicians who prescribe lithium should be aware of them. Further structured studies are needed to better understand these lithium rare adverse effects and the appropriate way to assess and monitoring them.

[Gustatory disorders in COVID-19]. / Narusheniya vkusooshchushcheniya pri COVID-19.

Taste disturbances are present in 20.3-88.0% of COVID-19 cases and are the first signs of infection in 11.0-18.1% of cases. They often manifested 3-7 days after the onset of general respiratory symptoms and last 2 to 16 days, followed by recovery. There are also prolonged disturbances of taste sensation (up to 61-76 days or more), which is associated with damage to various types of receptor cells of the mucous membrane of the tongue. More severe taste disturbances are recorded in the elderly. In women, changes in taste sensation are noted more often than in men, and with a longer recovery period. Severe and critical forms of taste disorders predominate in COVID-19; dysgeusia, as a rule, prevails over hypogeusia and ageusia. Taste disturbance is a common clinical symptom in COVID-19, which can and should be considered as a marker of early manifestation of coronavirus infection.

Factors associated with development and persistence of post-COVID conditions: A cross-sectional study.

INTRODUCTION: The post-COVID condition has become a social concern. Although the patient characteristics associated with the development of this condition are partially known, those associated with its persistence have not been identified. METHODS: We conducted a cross-sectional questionnaire-based survey among patients who had recovered from COVID-19 and visited the National Center for Global Health and Medicine between February 2021 and March 2021. Demographic and clinical data, and data regarding the presence and duration of post-COVID conditions were obtained. We identified factors associated with the development and persistence of post-COVID conditions using multivariate logistic and linear regression analyses, respectively. RESULTS: We analyzed 457 of 526 responses (response rate, 86.9%). The median patient age was 47 years. Of these, 378 patients (84.4%) had mild disease in the acute phase. The number of patients with symptoms at 6 and 12 months after onset or diagnosis was 120 (26.3%) and 40 (8.8%), respectively. Women were at risk of developing fatigue (odds ratio [OR]: 2.03, 95% confidence interval [CI]: 1.31-3.14), dysosmia (OR: 1.91, 95%CI: 1.24-2.93), dysgeusia (OR: 1.56, 95%CI: 1.02-2.39), hair loss (OR: 3.00, 95%CI: 1.77-5.09), and persistence of any symptoms (coefficient: 38.0, 95%CI: 13.3-62.8). Younger age and low body mass index were factors for developing dysosmia (OR: 0.96, 95%CI: 0.94-0.98 and OR: 0.94, 95%CI: 0.89-0.99, respectively) and dysgeusia (OR: 0.98, 95%CI: 0.96-1.00 and OR: 0.93, 95%CI: 0.88-0.98, respectively). CONCLUSION: We identified factors involved in the development and persistence of post-COVID conditions. Many patients, even those with mild conditions, experience long-term residual symptoms.