Association of prior military service with olfactory function among older adults.

Objective: Olfactory dysfunction (OD) is a condition primarily affecting older adults. Several factors have been implicated in OD, such as age, socioeconomic status, and neurodegenerative disease; however, the effect of military service still requires additional investigation. Here, we aim to determine if there is an association between prior military service and OD among older adults. Methods: This cross-sectional study included 2268 adults from Round 1 of the National Social Life, Health, and Aging Project. OD was defined as 0-3 odors correctly identified on the 5-item Sniffin' Sticks test. Bivariate analysis was conducted to calculate crude odds ratios (cOR) for the association of prior military service with OD and identify covariates for regression. Associations between prior military service and OD were assessed using logistic regression, and adjusted odds ratios (aOR) were calculated controlling for age, gender, race/ethnicity, education, stroke history, dementia, diabetes, and mental health. All analyses were weighted using survey weights to account for sampling design. Results: OD was present in 489 adults (21.6%). Among those with OD, the average age was 71.0 ± 7.9 years, whereas the average age in those without OD was 67.0 ± 7.2 years. Among adults with OD, 34.4% reported prior military service, compared to 27.7% of adults without OD (cOR = 1.37; 95% CI: 1.05-1.79). However, after adjusting for covariates, prior military service was not associated with OD (aOR: 1.09; 95% CI: 0.79-1.50). Older age (aOR: 1.07; 95% CI: 1.05-1.09) and worse mental health (aOR: 1.68; 95% CI: 1.14-2.49) were associated with OD. Conclusion: Prior military service was not associated with OD among older adults after controlling for covariates. More nuanced research is needed to examine correlations between OD and specific elements of military service such as duration, toxin exposure, and head trauma.Level of Evidence: Level 4.

Comparative imaging study of patients with persistent olfactory dysfunction due to mild COVID-19 using structural and functional MRI.

INTRODUCTION: Persistent post-COVID olfactory dysfunction continues to be studied due to the controversy in its pathophysiology and neuroimaging. MATERIALS AND METHODS: The patients had confirmed mild COVID-19 infection with olfactory dysfunction of more than one month of evolution and they were compared to controls with normal olfaction, assessed using the Sniffin' Sticks Olfactory Test and underwent brain, magnetic resonance imaging (MRI) of the olfactory bulb and olfactory function. RESULTS: A total of 8 patients and 2 controls participated. The average age of the patients was 34.5 years (SD 8.5), and that of the controls was 28.5 (SD 2.1). The average score in the patients' olfactory test was 7.9 points (SD 2.2). In brain and olfactory bulb MRI tests, no morphological differences were found. When evaluated by functional MRI, none of the patients activated the entorhinal area in comparison to the controls, who did show activation at this level. Activation of secondary olfactory areas in cases and controls were as follows: orbitofrontal (25% vs 100%), basal ganglia (25% vs 50%) and insula (38% vs 0%) respectively. CONCLUSIONS: There were no observed morphological changes in the brain MRI. Unlike the controls, none of the patients activated the entorhinal cortex in the olfactory functional MRI.

Prevalence and factors associated with olfactory impairment among patients with acne treated with oral isotretinoin: a cross-sectional study.

OBJECTIVE: This study aimed to investigate the prevalence and factors associated with olfactory dysfunction in individuals exposed to Isotretinoin (ISO) for the treatment of acne, using the University of Pennsylvania Smell Identification Test (UPSIT®). METHODS: This cross-sectional study enrolled age and sex-matched patients with acne who were current users of oral ISO and unexposed controls without olfactory complaints. UPSIT® and a validated questionnaire (Nasal Obstruction Symptom Evaluation) were administered to evaluate nasal obstruction in patients exposed to ISO. RESULTS: A total of seventy patients were recruited, with 35 in the exposed group and 35 in the unexposed group, consisting of 18 males and 17 females in each group, aged from 17 to 47 years. The prevalence of olfactory dysfunction was higher in the exposed group compared to the non-exposed group (62.9% vs. 17.1%), yielding a Prevalence Ratio (PR) of 3.7 (95% CI 1.9-7.1). However, no participants were categorized as anosmia or severe hyposmia and the majority of dysfunction was mild hyposmia compared to moderate hyposmia (51.5% vs. 11.4%). Among the exposed individuals, gasoline, orange, coffee, and wood exhibited the highest rates of identification errors (≥54%). Olfactory function demonstrated a negative correlation with treatment duration (p = 0.01), cumulative dose (p = 0.02), and nasal obstruction (p = 0.02). CONCLUSIONS: Olfactory dysfunction was more prevalent among ISO users, despite the patients being unaware of the disorder. Olfactory changes were correlated with treatment duration, cumulative dose, and nasal obstruction. LEVEL OF EVIDENCE: Level 4.

Effectiveness of platelet-rich plasma in long-lasting post-viral olfactory dysfunction: a case-series.

OBJECTIVE: To investigate the platelet-rich plasma (PRP) effectiveness in patients with a long-lasting postviral olfactory dysfunction (LPOD). METHODS: Forty-three consecutive patients with a long-lasting postviral OD were prospectively recruited. The injection of 1 mL of PRP was carried out in both olfactory clefts. The pre- to 6-month post-PRP injection change in olfaction was assessed with the olfactory disorder questionnaire (ODQ) and the threshold, discrimination, and identification (TDI) tests. RESULTS: Forty-three patients received bilateral PRP injections (24 females). The mean age of patients was 58.9 ± 16.8 years. The mean duration of LPOD was 8.7 years. The pre to 6-month post-injection mean TDI significantly improved from 10.3 ± 10.2 to 20.12 ± 12.07 (p = 0.001). The mean ODQ significantly decreased from 29.8 ± 13.0 to 23.4 ± 11.3 (p = 0.013). The average change of the TDI and the ODQ were 9.8 and 6.4, respectively. Age was inversely associated with the 6-month threshold score. CONCLUSION: PRP appears to be a promising therapeutic strategy for long-lasting postviral OD. Our findings support the conduction of controlled randomized trial in this population of patients.

A non-invasive AI-based system for precise grading of anosmia in COVID-19 using neuroimaging.

COVID-19 (Coronavirus), an acute respiratory disorder, is caused by SARS-CoV-2 (coronavirus severe acute respiratory syndrome). The high prevalence of COVID-19 infection has drawn attention to a frequent illness symptom: olfactory and gustatory dysfunction. The primary purpose of this manuscript is to create a Computer-Assisted Diagnostic (CAD) system to determine whether a COVID-19 patient has normal, mild, or severe anosmia. To achieve this goal, we used fluid-attenuated inversion recovery (FLAIR) Magnetic Resonance Imaging (FLAIR-MRI) and Diffusion Tensor Imaging (DTI) to extract the appearance, morphological, and diffusivity markers from the olfactory nerve. The proposed system begins with the identification of the olfactory nerve, which is performed by a skilled expert or radiologist. It then proceeds to carry out the subsequent primary steps: (i) extract appearance markers (i.e., 1 s t and 2 n d order markers), morphology/shape markers (i.e., spherical harmonics), and diffusivity markers (i.e., Fractional Anisotropy (FA) & Mean Diffusivity (MD)), (ii) apply markers fusion based on the integrated markers, and (iii) determine the decision and corresponding performance metrics based on the most-promising classifier. The current study is unusual in that it ensemble bags the learned and fine-tuned ML classifiers and diagnoses olfactory bulb (OB) anosmia using majority voting. In the 5-fold approach, it achieved an accuracy of 94.1%, a balanced accuracy (BAC) of 92.18%, precision of 91.6%, recall of 90.61%, specificity of 93.75%, F1 score of 89.82%, and Intersection over Union (IoU) of 82.62%. In the 10-fold approach, stacking continued to demonstrate impressive results with an accuracy of 94.43%, BAC of 93.0%, precision of 92.03%, recall of 91.39%, specificity of 94.61%, F1 score of 91.23%, and IoU of 84.56%. In the leave-one-subject-out (LOSO) approach, the model continues to exhibit notable outcomes, achieving an accuracy of 91.6%, BAC of 90.27%, precision of 88.55%, recall of 87.96%, specificity of 92.59%, F1 score of 87.94%, and IoU of 78.69%. These results indicate that stacking and majority voting are crucial components of the CAD system, contributing significantly to the overall performance improvements. The proposed technology can help doctors assess which patients need more intensive clinical care.

The long-term effect of COVID-19 infection on olfaction and taste; a prospective analysis.

PURPOSE: To estimate long-term prognosis of chemosensory dysfunctions among patients recovering from COVID-19 disease. METHODS: Between April 2020 and July 2022, we conducted a prospective, observational study enrolling 48 patients who experienced smell and/or taste dysfunction during the acute-phase of COVID-19. Patients were evaluated for chemosensory function up to 24 months after disease onset. RESULTS: During the acute-phase of COVID-19, 80% of patients reported anosmia, 15% hyposmia, 63% ageusia, and 33% hypogeusia. At two years' follow-up, 53% still experienced smell impairment, and 42% suffered from taste impairment. Moreover, 63% of patients who reported parosmia remained with olfactory disturbance. Interestingly, we found a negative correlation between visual analogue scale scores for smell and taste impairments during the acute-phase of COVID-19 and the likelihood of long-term recovery. CONCLUSION: Our study sheds light on the natural history and long-term follow-up of chemosensory dysfunction in patients recovering from COVID-19 disease. Most patients who initially suffered from smell and/or taste disturbance did not reach full recovery after 2 years follow-up. The severity of impairment may serve as a prognostic indicator for full recovery.

Therapeutic effects of olfactory training and systemic vitamin A in patients with COVID-19-related olfactory dysfunction: a double-blinded randomized controlled clinical trial.

OBJECTIVES: The new corona virus infection, has a wide range of clinical manifestations. Fever and cough are the most common symptoms. The olfactory function may be also affected with COVID-19. In this randomized clinical trial, we wanted to evaluate the therapeutic effect of olfactory training with and without oral vitamin A for COVID-19-related olfactory dysfunction. METHODS: Patients answered to the standard Persian version of anosmia reporting tool and performed the quick smell test before and after 12 weeks and at the end of the 12 months follow up. The patients were randomly allocated to three groups; Group A treatment with olfactory training, Group B treatment with oral vitamin A and olfactory training, and Group C as control group which only underwent nasal irrigation twice a day. Patients were treated for 3 months and followed up for 12 months. RESULTS: Totally 90 patients were included in three groups. After interventions, 76.9% of patients in Group A, 86.7% of patients in Group B, and 26.7% of patients in Group C completely improved. The average intervention time was statistically significant in relationship with the final olfactory status of the patients in the 12 months follow-up. The olfactory training has significantly improved the smell alteration at the end of 3- and 12- months follow-up in A and B groups. CONCLUSION: A three-months olfactory training is effective for improvement of COVID-19-related olfactory dysfunction. Adding daily oral vitamin A to olfactory training did not lead to better results in improving olfactory dysfunction. LEVEL OF EVIDENCE: Step 2 (Level 2*): Randomized trial.

Self-Reported Hypersensitivity to Smells: Objective Evidence for Hyposmia, not Hyperosmia.

OBJECTIVE: To compare, using state-of-the-art psychophysical tests, the olfactory function of patients complaining and not complaining of olfactory hypersensitivity. STUDY DESIGN: Retrospective cross-sectional. SETTING: The Smell and Taste Center at the University of Pennsylvania. METHODS: University of Pennsylvania Smell Identification Test (UPSIT) scores were obtained from 148 patients complaining of hyperosmia and 494 patients with no such complaints; detection threshold test scores were obtained from 77 and 483 patients of these respective groups. The effects of subject group, age, and sex on the test scores were assessed using analyses of variance. Categorical variables were evaluated by χ2. Responses to items within a detailed intake questionnaire, for example, the Beck Depression Inventory (BDI-II), were also evaluated. RESULTS: Unexpectedly, those complaining of hyperosmia had lower olfactory test scores than those with no such complaints (respective UPSIT means [95% confidence interval [CIs]] = 27.86 (26.85, 28.87) and 32.19 (31.67, 32.71); P < .001; respective threshold means (log vol/vol) = -4.49 (-4.89, -4.09) and -5.22 (-5.36, -5.06); P < .001). Remarkably, 70.95% of the self-identified hyperosmics exhibited mild to severe microsmia. The hyposmia complainers also exhibited elevated BDI scores (11.02 [9.53, 12.51] vs 7.58 [6.80, 8.34]). CONCLUSION: When objectively tested, many patients who complain of hypersensitivity to odors are actually less sensitive to them. The basis of this phenomenon is unclear. It could reflect the presence of emotionally disturbing altered smell sensations, or one or more comorbidities, such as hypochondria or osmophobia. These findings point to the importance of objective testing of persons with complaints of chemosensory dysfunction and reiterate the inaccuracy of self-reports.

Noninvasive Diagnostic Method to Objectively Measure Olfaction and Diagnose Smell Disorders by a Molecularly Targeted Fluorescence Imaging Agent.

Despite the recent advances in understanding the mechanisms of olfaction, no tools are currently available to noninvasively identify loss of smell. Because of the substantial increase in patients presenting with coronavirus disease 2019-related loss of smell, the pandemic has highlighted the urgent need to develop quantitative methods. Methods: Our group investigated the use of a novel fluorescent probe named Tsp1a-IR800P as a tool to diagnose loss of smell. Tsp1a-IR800P targets sodium channel 1.7, which plays a critical role in olfaction by aiding the signal propagation to the olfactory bulb. Results: Intuitively, we have identified that conditions leading to loss of smell, including chronic inflammation and coronavirus disease 2019, correlate with the downregulation of sodium channel 1.7 expression in the olfactory epithelium, both at the transcript and at the protein levels. We demonstrated that lower Tsp1a-IR800P fluorescence emissions significantly correlate with loss of smell in live animals-thus representing a potential tool for its semiquantitative assessment. Currently available methods rely on delayed subjective behavioral studies. Conclusion: This method could aid in significantly improving preclinical and clinical studies by providing a way to objectively diagnose loss of smell and therefore aid the development of therapeutic interventions.

Case report: An adolescent female with anosmic hypogonadotropic hypogonadism, intellectual disability, and papillary thyroid carcinoma: heterozygous deletion of TCF12.

Background: Isolated hypogonadotropic hypogonadism is a heterogeneous clinical entity. There is a growing list of molecular defects that are associated with hypogonadotropic hypogonadism (HH). TCF12, a recently identified molecular defect, causes craniosynostosis and is suggested to be used as a biomarker for prognosis in various cancer types. Recently, TCF12 variants were shown in a cohort with HH. Case presentation: A 15.3 years old female patient was referred to the endocrinology clinic for obesity. She had been gaining weight from mid-childhood. She had her first epileptic seizure at the age of 15.1 years and mildly elevated thyroid autoantibodies were detected during evaluation for etiology of seizures. She had not experienced menarche yet. She was operated for left strabismus at the age of 7 years. School performance was poor and she was receiving special education. Tanner stage of breast was 1 and pubic hair was 3. The endocrine workup revealed hypogonadotropic hypogonadism. Also, the Sniffin' Sticks test detected anosmia. Thyroid ultrasonography was performed due to the mildly elevated thyroid autoantibodies, and thyroid nodules with punctate calcifications were detected. Total thyroidectomy and central lymph node dissection were performed regarding the cytological findings of the nodules and multicentric papillary thyroid carcinoma with no lymph node metastasis was detected on pathology specimens. Regarding the phenotypic features of the patients, whole exome sequencing was performed and heterozygous deletion of exon 1 and exon 6-8 in TCF12 was detected. Conclusion: Haploinsufficiency of TCF12 causes anosmic HH. Probably due to the incomplete penetrance and variable expressivity of the disease, patients could display variable phenotypic features such as intellectual disability, developmental delay, and craniosynostosis. Further description of new cases with TCF12 variations could enhance our understanding of craniosynostosis and its potential link to Kallmann syndrome associated with this gene.

The Long-Term Loss of Smell and Taste in COVID-19 Patients ­ A Systematic Review and Meta-Analysis

Introduction: Olfactory symptoms have been reported as particular in COVID-19 patients. Objective: To synthesize and analyze the existing evidence on the monitoring loss of sense of smell and taste in COVID-19 patients, and for how long symptoms persist after the virus is no longer active in the organism. Methods: A search was implemented in PubMed, Embase, Scopus, Science Direct, and Web of Science databases. This systematic review and meta-analysis were conducted according to PRISMA, and the risk of bias was assessed through the Newcastle-Ottawa Scale. The review protocol is registered in PROSPERO. Results: Our systematic review included data from 14 articles with a total of 2143 participants. The most reported sensory symptom of COVID-19 was anosmia, which was detected in 1499 patients, being the only symptom to appear in all studies. Ageusia was detected in 595 patients, dysgeusia in 514 patients, and hyposmia in 209 patients. The studies provided the number of 729 patients with sensory symptoms during the acute COVID-19 infection of 15 days, and 1020 patients with lasting sensory symptoms, presenting sensory dysfunctions after the average latent period of 15 days of the acute COVID-19 infection. Conclusion: Evidence points to the loss or dysfunction of taste and smell as one of the symptoms of COVID-19 persisting for an average time of 15 days, with 44% of COVID-19 patients with persistent symptoms for more than 15 days. Nevertheless, most studies do not perform a follow-up with those patients. Therefore, further research on sensory symptoms and their follow-up is required.

Mice learn to identify and discriminate sugar solutions based on odor cues.

This study examined how olfaction impacts ingestive responses of mice to sugar solutions. Experiment 1 asked whether naïve C57BL/6 (B6) mice could identify 1 M glucose, fructose, or sucrose solutions based on odor cues, during a 30-min 2-bottle acceptability test. We tested mice both before and after they were rendered anosmic with ZnSO4 treatment. We used 2 indirect measures of odor-mediated response: number of trials initiated and latency to initiate licking. Before ZnSO4 treatment, the mice learned how to identify 1 M glucose and fructose (but not sucrose) solutions based on odor cues. ZnSO4 treatment eliminated their ability to identify the glucose and fructose solutions. Experiment 2 asked whether 2 d of exposure to a 1 M glucose, fructose, or sucrose solution improved the identification of the same sugar solution. Following exposure, the B6 mice identified all 3 sugar solutions based on odor cues. Experiment 3 asked whether T1R3 knockout mice (i.e. mice lacking the T1R3 subunit of the T1R2 + R3 sweet taste receptor) could learn to discriminate 0.44 M glucose and fructose solutions based on odor cues. All mice were subjected to a 1-h preference test, both before and after exposure to the 0.44 M glucose and fructose solutions. During exposure, the experimental mice received ZnSO4 treatment, whereas the control mice received saline treatment. Before exposure, neither type of mouse preferred the glucose solution. After exposure, the control mice preferred the glucose solution, whereas the experimental mice did not. Our results reveal that mice can learn to use odor cues to identify and discriminate between sugar solutions.

Magnetic resonance spectroscopy findings of brain olfactory areas in patients with COVID-19-related anosmia: A preliminary comparative study.

Objectives: 2019 novel coronavirus disease (COVID-19) infection is commonly associated with olfactory dysfunctions, but the basic pathogenesis of these complications remains controversial. This study seeks to evaluate the value of magnetic resonance spectroscopy (MRS) in determining the molecular neurometabolite alterations within the main brain olfactory areas in patients with COVID-19-related anosmia. Methods: In a cross-sectional study, seven patients with persistent COVID-19-related anosmia (mean age: 29.57 years) and seven healthy volunteers (mean age: 27.28 years) underwent MRS in which N-acetyl-aspartate (NAA), choline (Cho), creatine (Cr), and their ratios were measured in the anterior cingulate cortex, dorsolateral prefrontal cortex, orbitofrontal cortex (OFC), insular cortex, and ventromedial prefrontal cortex. Data were analyzed using TARQUIN software (version 4.3.10), and the results were compared with an independent sample t-test and nonparametric Mann-Whitney test based on the normality of the MRS data distribution. Results: The mean duration of anosmia before imaging was 8.5 months in COVID-19-related anosmia group. MRS analysis elucidated a significant association between MRS findings within OFC and COVID-19-related anosmia (P disease < 0.01), and NAA was among the most important neurometabolites (P interaction = 0.006). Reduced levels of NAA (P < 0.001), Cr (P < 0.001) and NAA/Cho ratio (P = 0.007) within OFC characterize COVID-19-related anosmia. Conclusions: This study emphasizes that MRS can be illuminating in COVID-19-related anosmia and indicates a possible association between central nervous system impairment and persistent COVID-19-related anosmia.

COVID-19-related chemosensory changes: Findings from a prospective national database.

Objective: The aim of this study was to review findings from a large prospective national database of chemosensory disturbances associated with coronavirus disease 2019 (COVID-19) infection. Data Sources: The Virginia Commonwealth University Smell and Taste Center national database of COVID-19 chemosensory disturbances. Methods: A series of online surveys, first opened on April 10, 2020, was made accessible nationwide to any adult with sudden chemosensory dysfunction since January 2020. Participants received subsequent follow-up surveys 14 days, 1 month, 3 months, and 6 months after enrollment. An additional survey was sent to all participants on May 28, 2022 to assess long-term outcomes. Information pertaining to demographics, symptoms, comorbidities, treatments, and life impact was collected. Results: Of 363 participants who reported complete smell recovery, 51.2% recovered within 1 month, 70% within 3 months, and 79% within 6 months, while 8.8% took over 1 year to completely recover. Among all participants, 7.5% had no smell recovery. Positive predictors of recovery included age <40, male gender, and the presence of nasal congestion. Negative predictors included difficulty breathing and prior head injury. Many participants reported a decrease in quality of life and the presence of potential safety hazards associated with decreased smell loss. Conclusions: Most subjects with COVID-19-related chemosensory dysfunction recover, with the majority noting complete recovery within weeks of infection. Those aged over 40 years and female gender were associated with lower rates of recovery. A considerable number of participants reported significant impact on quality of life and safety.

Recovery rates and long-term olfactory dysfunction following COVID-19 infection.

Objectives: Olfactory dysfunction is one of the most recognized symptoms of COVID-19, significantly impacting quality of life, particularly in cases where recovery is prolonged. This review aims to explore patterns of olfactory recovery post-COVID-19 infection, with particular focus on delayed recovery. Data Sources: Published literature in the English language, including senior author's own work, online and social media platforms, and patients' anecdotal reports. Method: A comprehensive review of the literature was undertaken by the authors with guidance from the senior author with expertise in the field of olfaction. Results: Based on self-report, an estimated 95% of patients recover their olfactory function within 6 months post-COVID-19 infection. However, psychophysical testing detects higher rates of persistent olfactory dysfunction. Recovery has been found to continue for at least 2 years postinfection; negative prognostic indicators include severe olfactory loss in the acute phase, female sex, and older age. Variability in quantitative and qualitative disturbance in prolonged cases likely reflects both peripheral and central pathophysiological mechanisms. Limitations of many of the reviewed studies reflect lack of psychophysical testing and baseline olfactory assessment. Conclusions: Post-COVID-19 olfactory dysfunction remains a significant health and psychosocial burden. Emerging evidence is improving awareness and knowledge among clinicians to better support patients through their olfactory rehabilitation, with hope of recovery after several months or years. Further research is needed to better understand the underlying pathogenesis of delayed recovery, identify at risk individuals earlier in the disease course, and develop therapeutic targets.

The current possibilities of diagnosing and therapies for olfactory disorders.

INTRODUCTION: Olfactory disorders significantly affect individuals, diminishing their capacity to detect dangers, appreciate flavors, and engage socially. Despite their considerable impact on quality of life, these disorders often receive less attention compared to other sensory impairments. This review emphasizes the importance of olfactory function and explores both traditional and innovative diagnostic and therapeutic approaches. AREAS COVERED: This review comprehensively covers the pathophysiology, diagnostic challenges, and treatment options for olfactory disorders. It delves into the nuances of different disorders, such as anosmia and parosmia, and discusses the array of diagnostic tools from traditional sniff tests to advanced imaging techniques. The review also evaluates therapeutic strategies, from pharmacological treatments to emerging therapies like electrical stimulation and regenerative medicine, highlighting recent advances in the field. EXPERT OPINION: Current insights suggest a growing recognition of the significance of olfactory disorders, driven by recent pandemics and advances in diagnostic and therapeutic technologies. Future perspectives indicate a promising direction toward more personalized medicine approaches and enhanced regenerative therapies. Continuous research and improved clinical awareness are critical for evolving the management strategies of olfactory impairments, potentially leading to better patient outcomes and quality of life enhancements.

Using Cooking Schools to Improve the Pleasure of Food and Cooking in Patients Experiencing Smell Loss.

Smell loss affects around 15-20% of the population, with a major effect on the quality of life. The most common complaint is the impairment of the eating experience, with around 90% of patients reporting this issue. A study conducted at a specialised Taste and Smell Clinic investigated if food and cooking can positively affect the enjoyment of food, subjective cooking skills, and quality of life in patients with smell loss. The 49 participants in the study received a 5-week cooking school course that focused on emphasizing the other senses to regain the enjoyment of food. Participants gained more confidence in cooking, and their quality of life improved significantly. Positively evaluated recipes were adjusted based on feedback and published as free e-books in Danish, German, and English. Eating and cooking are multisensory experiences, and the perception of food depends on the complex interaction of senses and surroundings. If the olfactory input is reduced or absent, both the enjoyment and cooking experience can be negatively affected. Therefore, focusing on food and cooking can have a positive impact on patients with smell loss.

Traditional Chinese medicine for post-viral olfactory dysfunction: A systematic review.

Background: Post-viral olfactory dysfunction (PVOD) is the common symptoms of long COVID, lacking of effective treatments. Traditional Chinese medicine (TCM) is claimed to be effective in treating olfactory dysfunction, but the evidence has not yet been critically appraised. We conducted a systematic review to evaluate the effectiveness and safety of TCM for PVOD. Methods: We searched eight databases to identified clinical controlled studies about TCM for PVOD. The Cochrane risk of bias tools and GRADE were used to evaluate the quality of evidence. Risk ratio (RR), mean differences (MD), and 95 % confidence interval (CI), were used for effect estimation and RevMan 5.4.1 was used for data analysis. Results: Six randomized controlled trials (RCTs) (545 participants), two non-randomized controlled trials (non-RCTs) (112 participants), and one retrospective cohort study (30 participants) were included. The overall quality of included studies was low. Acupuncture (n = 8) and acupoint injection (n = 3) were the mainly used TCM therapies. Five RCTs showed a better effect in TCM group. Four trials used acupuncture, and three trials used acupoint injection. The results of two non-RCTs and one cohort study were not statistically significant. Two trials reported mild to moderate adverse events (pain and brief syncope caused by acupuncture or acupoint injection). Conclusions: Limited evidence focus on acupuncture and acupoint injection for PVOD and suggests that acupuncture and acupoint injection may be effective in improving PVOD. More well-designed trials should focus on acupuncture to confirm the benefit. Protocol registration: The protocol of this review was registered at PROSPERO: CRD42022366776.

Olfactory Dysfunctions and Chronic Kidney Disease: A Scoping Review.

Chronic kidney disease (CKD) represents a significant global public health challenge. Among the various clinical complications associated with CKD, olfactory dysfunction has been identified as a factor that substantially affects the quality of life of patients. This study aims to systematically explore the prevalence, implications, and therapeutic avenues of anosmia in CKD patients. This scoping review utilized the Arksey and O'Malley framework, incorporating the Joanna Briggs Institute methodology, and followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines. The research question, formulated using the PIO framework, guided a thorough search of databases PubMed/Medline, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane Library and gray literature sources. Eligibility criteria focused on studies involving CKD patients with olfactory dysfunctions. From an initial pool of 832 articles, 17 studies met the criteria, providing insights into olfactory alterations in 4,025 CKD patients. The data that have been reported, define that 55,34% of the sample experienced olfactory changes and the 8.5% experienced anosmia. This review revealed a complex interplay of factors contributing to olfactory alterations, including uremic toxins, dialysis procedures, electrolyte imbalances, and malnutrition. Findings suggested the potential recovery of olfactory function following kidney transplantation. Various assessment tools were utilized, with the University of Pennsylvania Smell Identification Test and Sniffin' Sticks emerging as the primary instruments. The observed variability in findings highlights the need for continued research to understand the mechanisms, enhance therapies, and improve quality of life for CKD patients with olfactory dysfunctions. Future studies should employ standardized methods, explore new assessment tools, and prioritize longitudinal assessments to advance our understanding and management of olfactory dysfunctions in this population.

Persistent Neurological Deficits in Mouse PASC Reveal Antiviral Drug Limitations.

Post-Acute Sequelae of COVID-19 (PASC) encompasses persistent neurological symptoms, including olfactory and autonomic dysfunction. Here, we report chronic neurological dysfunction in mice infected with a virulent mouse-adapted SARS-CoV-2 that does not infect the brain. Long after recovery from nasal infection, we observed loss of tyrosine hydroxylase (TH) expression in olfactory bulb glomeruli and neurotransmitter levels in the substantia nigra (SN) persisted. Vulnerability of dopaminergic neurons in these brain areas was accompanied by increased levels of proinflammatory cytokines and neurobehavioral changes. RNAseq analysis unveiled persistent microglia activation, as found in human neurodegenerative diseases. Early treatment with antivirals (nirmatrelvir and molnupiravir) reduced virus titers and lung inflammation but failed to prevent neurological abnormalities, as observed in patients. Together these results show that chronic deficiencies in neuronal function in SARS-CoV-2-infected mice are not directly linked to ongoing olfactory epithelium dysfunction. Rather, they bear similarity with neurodegenerative disease, the vulnerability of which is exacerbated by chronic inflammation.