Olfactory Disorders Research Articles

Platelet-Rich Plasma for Treating COVID-19-Related Anosmia, Hyposmia, and Parosmia: A Controlled Longitudinal Study.

To investigate the effectiveness of platelet-rich plasma (PRP) injection into the olfactory clefts of coronavirus disease 2019 (COVID-19) patients with persistent anosmia, hyposmia, and parosmia. Controlled study. Multicenter study. From March 2022 to July 2024, 514 COVID-19 patients undergoing PRP injection and olfactory training versus olfactory training (controls) for a persistent olfactory dysfunction (OD) were consecutively recruited from two medical centers. Subjects were evaluated from pre- to 3 months post-injection with the olfactory disorder questionnaire (ODQ) and the threshold, discrimination, and identification (TDI) test. Olfactory outcomes were compared between controls and patients considering the type of OD (anosmia, hyposmia, and parosmia). The PRP group was composed of 416 patients with anosmia (N = 111; 26.7%), hyposmia (N = 160; 38.5%), and parosmia (N = 145; 34.9%). The baseline ODQ of patients with parosmia was significantly higher than those of the other groups (P = .001). The increase in TDI subscores and total score was significantly higher in all PRP subgroups compared to controls (P = 0.001). The ODQ significantly reduced from pre- to post-PRP injection in hyposmia and parosmia groups (P = 0.001). Patients with parosmia showed a significantly greater reduction in ODQ scores compared to the control group. The 3-month TDI score was negatively influenced by the age of patients (rs = -0.263; P = 0.001) and the duration of OD (rs = -0.213; P = .001). Patients with parosmia experienced a stronger impact of OD on quality of life (QoL), and showed greater QoL improvement following PRP injections compared to other groups.

Interrelationships Between Plasma Levels of Brain Natriuretic Peptide and Prolonged Symptoms Due to Long COVID

Objectives: Evidence for the usefulness of biomarkers that aid in diagnosis, assessment of severity, and prediction of prognosis in patients with long COVID is limited. The aim of this study was to clarify the characteristics of brain natriuretic peptide (BNP) in long COVID. Methods: We conducted a retrospective observational study of patients who visited the COVID-19 aftercare outpatient clinic at Okayama University Hospital from February 2021 to April 2024. Results: A total of 428 patients were enrolled in this study, and the patients were divided into a group with normal BNP (n = 314, ≤18.4 pg/mL) and a group with increased BNP (n = 114, >18.4 pg/mL). The long COVID group with increased BNP had a higher proportion of females (44.3% vs. 73.7%, p < 0.01) and an older median age (38 vs. 51 years, p < 0.01). Fatigue and brain fog were commonly manifested in both groups, while dyspnea was a more frequent complaint in the group with increased BNP. Various symptoms including fatigue, palpitations, and taste and/or olfactory disorders were associated with elevated BNP (23 to 24 pg/mL). Memory impairment was also linked to higher BNP (OR: 2.36, p = 0.05). In long COVID patients, plasma BNP elevation appears to be more pronounced in females and is often related to cardiogenic factors, in which inflammatory responses are also involved. Conclusions: Plasma BNP measurement may be useful for evaluating the severity of long COVID, especially in female patients and those with respiratory symptoms and/or memory impairment.

Pharmacovigilance imbalance analysis of VEGFR-TKI-related taste and smell disorders

Taste and smell disorders (TSDs) can induce diminished interest in food, inadequate nutrient intake, and emotional irregularities, particularly among cancer patients. Previous research found that the main culprits of TSD development in cancer patients are cytotoxic drugs such as taxol, fluorouracil, cyclophosphamide, and anthracycline-based drugs. The advent of targeted drugs such as vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs) has significantly extended the survival time of cancer patients, and thus widely used in clinical practice. However, the association between the use of VEGFR-TKIs and the development of TSDs havs not been studied.The adverse event(AE) reports related to VEGFR-TKIs were downloaded from the FDA Adverse Event Reporting System (FAERS) database. Disproportionality analysis was conducted to assess the correlation between VEGFR-TKIs and TSDs. The Standardized Medical Dictionary for Regulatory Activities (MedDRA) Queries (SMQs) were used to analyze the AEs of TSDs. The study found a statistically significant correlation between the occurrence of TSDs and the use of VEGF-TKIs (cabozantinib, axitinib, pazopanib, sunitinib, nintedanib, and lenvatinib).However, the instructions for Nintedanib, Sorafenib and Lenvatinib were not mentioned. Capbottinib demonstrated the highest number of reports(1790 cases), also with the strongest association (ROR 95%CI-low = 16.51; PRR = 16.18; IC025 = 3.96) when analyzing the narrow SMQ of TSDs. Dysgeusia, taste disorder, and ageusia were the most commonly reported preferred terms (PTs) in VEGFR-TKI-related TSDs, accounting for more than 90% of the reported cases. Cabozantinib showed the highest number of reports and strongest correlation with ageusia, taste disorder, parosmia, and anosmia. The study found significant association between the reports of TSDs and the use of VEGFR-TKIs, indicating the monitoring of TSD development and appropriate management in clinical is necessary.

Olfactory Dysfunction in Children and Adolescents-A Diagnostic Pathway.

Olfactory disorders have so far played a subordinate role in pediatric care, although children can also be affected. Due to a lack of awareness, the diagnosis can often only be made after numerous visits to the doctor, although it can significantly impact the quality of life. Olfactory disorders in adults are usually acquired, while congenital causes dominate in children. To date, there are no specific recommendations for diagnosis in children. This article deals with the prevalence, causes, and diagnostic approaches of olfactory disorders in pediatrics. A structured diagnostic approach is fundamental, including a medical history and psychophysical olfactory tests, supplemented by specific examinations depending on the suspected diagnosis. Therapeutic approaches are limited, with a focus on counseling and olfactory training.

Parosmia: Pathophysiology and Management.

Parosmia is a qualitative olfactory disorder in which there is a mismatch between the memory of an odor and the actual experience triggered by an odor. There has been a surge in parosmia-related publications since the COVID-19 pandemic. This review summarizes the latest clinical findings, theories on pathophysiology and potential treatment options. Potential models of parosmia include peripheral or central hypotheses, which refer to aberrancies in olfactory neuron regeneration or information processing in central olfactory centers respectively. This leads to an incomplete or disorganized pattern of olfactory information relay. Studies using gas chromatography and functional magnetic resonance imaging have identified molecular triggers and intracranial functional connectivity patterns in parosmia respectively. Parosmia tends to occur in a delayed fashion after virus-induced anosmia. It may run a protracted course, but typically improves over time. Currently there are no generally approved, objective ways to ascertain the presence and measure the extent of parosmia. Evidence-based treatment for parosmia remains elusive. In some people, this can lead to health and quality of life issues.

Olfactory disorders after chemoradiotherapy in patients with head and neck cancer

Background: There are few prospective studies on the impact of chemoradiotherapy on the sense of smell in patients with head and neck cancer and none studied phantosmia and parosmia. This study investigates the impact of radiotherapy alone or with chemotherapy on the olfactory function of patients with head and neck cancer including hyposmia, phantosmia and parosmia after treatment. Methods: A prospective and observational study was conducted at a cancer referral hospital with 32 individuals with head and neck cancer (age 55.2 ± 10.5 years, mean ± standard deviation). All patients had their olfactory function assessed using subjective report of phantosmia and parosmia, and the University of Pennsylvania Smell Identification Test (UPSIT) before the start of radiotherapy and 1 month after its completion. A subset of patients was followed up to 6 months after radiotherapy. Results: Qualitative disturbances of smell were described by 28.1% of patients in the first month after radiotherapy. Some patients have these disorders even 3 months after radiotherapy. Phantosmia and parosmia episodes were not influenced by age, gender, race, UPSIT, smoking, previous or concomitant chemotherapy. We observed a significant decrease in UPSIT score 1 month after radiotherapy. Concomitant chemotherapy with cisplatin was the only independent predictor of change in UPSIT. The mean in the smell test was similar to baseline in the third month after radiotherapy. Conclusion: Almost one third of patients with head and neck cancer complain of phantosmia and parosmia episodes after radiotherapy. Individuals treated concomitantly with cisplatin has worst scores in the smell test after the end of the treatment.

Analysis of factors influencing quality of life in patients with olfaction disorders

Objective: To explore the differences in quality of life among patients with olfaction disorders (OD) due to various etiologies and to identify factors influencing olfactory-related quality of life. Methods: This cross-sectional study enrolled patients with OD who visited the Department of Otolaryngology at Fudan University Eye, Ear, Nose, and Throat Hospital between February and June 2024. Psychophysical olfactory test was performed using the Chinese Smell Identification Test (CSIT), which was based on the Chinese population, with the TDI score used as the total score for threshold (T), discrimination (D), and identification (I) tests. The quality of life related to OD was assessed using a brief version of the Questionnaire of Olfactory Disorders (bQOD), which included QOD-P, QOD-Q, and QOD-VAS. Visual analog scales (VAS) was used to rate the degree of subjective decline in olfaction. Statistical analysis was conducted to assess the impact of etiologies, age, gender, onset time, psychophysical olfactory tests, and subjective assessment on olfactory-related quality of life. Results: A total of 419 patients were enrolled, including 220 males and 199 females, with the age of (39.72±14.31) years (range: 5 to 76 years). Among the 419 patients, 380 completed the bQOD and VAS assessment. The results showed that there were intergroup differences in the QOD-P and QOD-Q scores among patients with OD caused by different etiologies (P values were 0.001 and 0.003, respectively). The QOD-P score was negatively correlated with age (P<0.05), and positively correlated with the TDI score (P<0.01). The QOD-Q score was negatively correlated with disease duration (P<0.05), and positively correlated with the patients' subjective olfactory decline as assessed by the VAS score (P<0.01), and had no significant correlation with psychophysical olfactory tests. Female patients had lower QOD-Q scores than male patients (P<0.05). The QOD-VAS score was positively correlated with the patients' subjective olfactory impairment (P<0.01) and showed no significant correlation with psychophysical olfactory tests. Female patients had worse QOD-VAS scores than male patients (P<0.05). Conclusion: Compared with psychophysical olfactory tests, VAS olfactory scores are more closely related to quality of life. Different etiologies, duration of the disease, and gender also affect olfactory-related quality of life.

SUBJECTIVE COGNITIVE CONCERNS AND NEUROPSYCHOLOGICAL PERFORMANCE IN PRODROMAL PARKINSON’S DISEASE

Abstract While subjective cognitive concerns (SCC) are commonly observed in preclinical Alzheimer’s disease, SCC in cognitively unimpaired individuals at risk for Parkinson’s disease (PD), as defined by reduced sense of smell (hyposmia) or REM behavior sleep disorder (RBD), is less understood. Therefore, this study examined associations between SCC and individual neuropsychological measures in the prodromal PD cohort (n=715, mean age=67.75) from the Parkinson’s Progression Markers Initiative (PPMI) study. SCC (n=199) or no SCC (n=516) was based on participant or caregiver report for item 1 on the Unified Parkinson’s Disease Rating Scale, part 1. Analyses of covariance, adjusting for age, education, sex/gender, race/ethnicity, psychiatric factors, motor symptoms, and prodromal classification (hyposmia or RBD), examined the association between SCC and measures of memory, language, visuoperception, processing speed, and executive functioning. Relative to participants without SCC, those with SCC had lower performance on Animal Fluency (B=-1.02, p=.009, np2=.011) and Symbol Digit Modalities (B=-1.68, p=.036, np2=.007). When examining the SCC x prodromal classification interaction, hyposmia or RBD status did not moderate the associations for Animal Fluency or Symbol Digit Modalities. Overall, SCC in prodromal PD participants was only associated with two measures requiring speeded retrieval and processing. Unlike in preclinical Alzheimer’s disease, where SCC is often linked to memory, no such association was found in prodromal PD. Instead, SCC was associated with speeded measures that are likely more sensitive to PD related changes. Future work will investigate the utility of SCC to predict conversion to PD and longitudinal rates of cognitive decline.

Post COVID syndrome. The classification of clinical forms

Background: After a coronavirus infection, a number of people have long-term health abnormalities, often requiring therapeutic intervention.. Aims: to describe the features of the course of the convalescence period in patients who have had a coronavirus infection caused by the SARS-CoV-2 virus.. Materials and methods: A special questionnaire was prepared for patients, which included questions to assess the course of the convalescence period in patients who had a coronavirus infection caused by the SARS-CoV-2 virus. The survey was conducted electronically on the platform testograf.ru .. Results: The study involved 24,126 people aged 18 to 95 years. After the primary disease, 67.58% of respondents had complaints, and 66.1% had complaints after the second one. Asthenic syndrome, cognitive and memory disorders were most often recorded, as well as respiratory function disorders (cough, shortness of breath) and gastrointestinal tract functions (diarrhea, constipation, dyspepsia), olfactory and taste disorders, hair loss. Skin manifestations, decreased visual acuity, complaints of frequent acute respiratory infections, sleep disorders, prolonged subfebrility and others were rare. Among the group of patients who had an exacerbation of somatic pathology, the most significant were diseases of the cardiovascular system and musculoskeletal system. After a coronavirus infection in the form of pneumonia in the period of convalescence, respiratory disorders were significantly more often recorded, and in the gastrointestinal form, damage to the gastrointestinal tract.. Conclusions: the classification of clinical forms of postcovid syndrome includes four main blocks of clinical manifestations of the period of convalescence of coronavirus infection: virus-associated manifestations, iatrogenic, genetically determined, associated with somatic pathology.

The Clinical Anatomy of SARS-CoV-2 Variants of Concern in Central Greece During October 2020-July 2022.

The emergence of SARS-CoV-2 variants of concern (VOCs) during the COVID-19 pandemic necessitates investigation into their clinical differentiation and outcomes. This study aimed to examine these differences among VOCs, considering multiple related factors. An observational cohort study was conducted on patients diagnosed with SARS-CoV-2 infection via nasopharyngeal/oropharyngeal swab who visited the emergency department of a public Greek hospital between October 2020 and July 2022 during different VOC circulation in the region. Data on clinical manifestations, outcomes, and medical history (comorbidities, prior SARS-CoV-2 infection, vaccination status against COVID-19) were collected through a questionnaire and medical records for those hospitalized. A total of 913 patients were included in this study (813 adults ≥18 years old, 100 children <18 years old). Significant differences were observed across VOCs for both adults and children. A lower proportion of children developed symptoms during the non-Omicron variants, 73.5%, compared to Omicron variants, 86.4%. Fever, dyspnea, and taste and smell disorders were observed more frequently among non-Omicron adult cases, in contrast to upper respiratory symptoms, which were more common symptoms among Omicron infections. The non-Omicron variants were associated with higher rates of hospitalization at 30.6%, pneumonia at 23.0%, and death at 6.1% compared to Omicron variants at 8.0%, 5.0%, and 1.8%, respectively. Vaccination against COVID-19 was shown to be a protective factor for severe outcomes. Our findings suggest distinct clinical presentations and outcomes associated with different VOCs. Despite the fact that current VOCs circulating are less severe, the COVID-19 vaccine continues to play a protective role for severe cases.

Ion Channels in Odor Information Processing of Neural Circuits of the Vertebrate Olfactory Bulb.

Olfactory disorders and their associated complications present a considerable challenge to an individual's quality of life and emotional wellbeing. The current range of treatments, including surgical procedures, pharmacological interventions, and behavioral training, frequently proves ineffective in restoring olfactory function. The olfactory bulb (OB) is essential for odor processing and plays a pivotal role in the development of these disorders. Despite the acknowledged significance of ion channels in sensory functions and related pathologies, their specific involvement in OB remains unexplored. This review presents an overview of the functions of various ion channel families in regulating neuronal excitability, synaptic transmission, and the complex processes of olfactory perception. The objective of this review was to elucidate the role of ion channels in olfactory function, providing new insights into the diagnosis and treatment of olfactory dysfunction.

Predictive model for postoperative unrecovered olfactory function in CRSwNP patients with olfactory disorder.

Olfactory disorder (OD) is a prevalent and challenging symptom in chronic rhinosinusitis with nasal polyps (CRSwNP). This study aims to investigate the risk factors and develop a predictive model for poor olfactory prognosis in CRSwNP patients with OD after endoscopic sinus surgery (ESS). Seventy-eight CRSwNP patients with OD who underwent ESS were enrolled. Preoperative and 6-month-postoperative olfactory function were assessed using Sniffin' Sticks. Receiver operating characteristics (ROC) curves were constructed to set the cutoff points. Risk factors were determined by logistic models. A power analysis was conducted to evaluate the sample size. Overall, 66.7% of CRSwNP patients had unrecovered olfaction after surgery. Patients with unrecovered olfaction displayed higher preoperative threshold-discrimination-identification (TDI) score, lower Questionnaire for Olfactory Disorders-Negative Statements (QOD-NS) score, lower total olfactory cleft score (TOCS), and fewer tissue eosinophils than those of the improved/recovered group. QOD-NS ≤ 5.0, preoperative TOCS ≤ 4.5 and tissue eosinophil count ≤ 8.3 were independent risk factors for unrecovered olfaction. Based on these variables, a predictive model was developed. The area under the ROC curve for the model was 0.845, and the optimal cutoff value was 2.0 points, with a sensitivity of 82.7% and specificity of 80.8%. Low levels of QOD-NS score (preoperative), TOCS (preoperative) and tissue eosinophil count are independent risk factors for short-term unrecovered olfaction in CRS patients with OD postoperatively. The predictive model developed here is practical and convenient for the early identification of poor prognosis of OD, enabling early additional intervention.

The relationship between intravenous olfactory test and taste disorder in patients with olfactory disorder.

The intravenous olfactory test (alinamin test [AT]) is a retronasal olfactory assessment and may evaluate the flavour disorder; however, studies assessing whether AT accurately determines the severity of taste disorders are lacking. Our study aims to evaluate the relationship between AT and subjective taste disorders in the patiensts with olfactory disorder. Between April 2019 and March 2020, 228 patients visited our smell clinic reporting olfactory disorders. Of these, 193 patients who underwent AT were included in this study. We evaluated the differences in AT response, latency time, and duration time between patients with and without subjective taste disorder. We also assessed the degree of subjective taste disorder experienced by patients using the visual analogue scale (VAS) and the correlation between latency and duration time of AT. To assess taste perception more broadly, we inquired about the presence of disorder using the term "taste" rather than "flavour" without focusing on any specific type of taste disorder. Of the included 193 patients, 62 reported awareness of a taste disorder. The duration time of AT was significantly shorter in patients with subjective taste disorder. A weak correlation was found between the VAS scores for subjective taste disorders and the duration time of AT. Our results showed that among the patients with olfactory disorders, the duration time of AT was reduced for those with subjective taste disorders.

Neurological and cognitive impairment in long‐term COVID‐19: clinical characterization in a longitudinal study and correlation with neuroimaging and biomarkers

AbstractBackgroundCOVID‐19 can course with persistent symptoms after infection in a condition called long Covid (NATH, 2020). In this context, cognitive complaints, sleep disorders, headache, smell disorders, in addition to anxiety and depression are common (DELGADO‐ALONSO et al, 2022; ISMAEL et al, 2021.). The present study aims to describe the cognitive manifestations in patients who had a previous COVID‐19 infection and is justified by the need to better explain the pathophysiological mechanisms behind these manifestations.MethodThis is a cross‐sectional view of a prospective longitudinal study carried out on an outpatient basis. Patients have been evaluated on an outpatient basis since March 2023. Patients were evaluated by a neurologist and sleep specialist, with the application of MMSE, GDS/BECK, Pittsburgh, Epworth, Pfeffer and CDR. In addition, a blood sample is collected to analyze APOE and markers of neurodegenerative and inflammatory processes (NfL, AB42, AB40, p‐tau, t‐tau, GFAP, alpha‐synuclein and clusterin). In addition, all patients will undergo cranial MRI, polysomnography and neuropsychological evaluation. The project is approved by the local CEP, all patients have signed an informed consent form.ResultSo far, 93 patients have been evaluated, with 79% female. 1.1% had &lt;4 years of schooling, 4.5% between 4‐8 years and 94.3% &gt; 8 years of schooling. The average duration of symptoms was about 2 years. The average age was 42.8 years. During the illness, only 13.9% were hospitalized, and 10.7% in the ICU. As for the applied batteries, 4.3% of the patients presented alterations in the Pfeffer, and 3.2% presented alterations in MMSE for education. As for post‐Covid symptoms, 96.7% had cognitive complaints, 73.1% sleep disorders, 63.4% anxiety, 35.4% headache, 32.2% depression and 24.7% smell disorders. Results of neuropsychological assessment, biomarkers, cranial MRI and PSNG are pending.ConclusionIn our study, cognitive manifestations and sleep disturbances were common in the Long Covid phase, even in a population with x months after the acute infection. In addition, cognitive complaints were common even in a sample with a mean age &lt; 50 years, after a mild case of Covid‐19 and with a high level of education.

Magnetic resonance imaging does not distinguish Kallmann syndrome from normosmic isolated hypogonadotropic hypogonadism.

Isolated hypogonadotropic hypogonadism (IHH) may be associated with pituitary gland and olfactory system disorders. We aimed to correlate findings of magnetic resonance imaging (MRI) of the pituitary gland and olfactory system in IHH patients with the patients' olfactory phenotype. The present research was a single-center retrospective case-control study. MRI patterns of the pituitary gland and olfactory system were studied in 46 patients, of whom 29 (63%) were classified on the basis of olfactometry as having Kallmann syndrome (KS) (16 patients with anosmia and 13 patients with hyposmia) and 17 (37%) as having normosmic IHH (nIHH). Results were compared with age- and sex-matched healthy controls. Genetic diagnosis was conducted in all IHH patients based on next-generation sequencing. Almost 70% prevalence of pituitary hypoplasia was observed in IHH subjects. Olfactory bulb (OB) abnormalities were identified in 80.4% of all patients, both the KS (82.8%) and the nIHH (76.5%) subjects. Incidence of unilaterally abnormal, hypoplastic olfactory sulcus (OS) was equally frequent in nIHH and KS. Statistically, piriform cortical thickness was significantly lower in all patient groups than in controls. MRI cannot exclusively differentiate between KS and nIHH, as both conditions may present with OB and OS abnormalities. A surprisingly high frequency of olfactory system abnormalities was observed in nIHH patients, while anterior pituitary hypoplasia was prevalent across all IHH patients. Notably, OB abnormalities were more predominant in KS patients than in those with nIHH.

Characteristics of subjective olfactory dysfunction and imaging features in patients with traumatic olfactory disorders: a retrospective case-control study.

Olfactory dysfunction caused by head trauma poses significant challenges in clinical diagnosis and treatment. The primary difficulty arises from direct injuries to olfactory-related brain tissues. Although imaging provides the most direct method to evaluate such injuries, there is no standardized international diagnostic criterion for olfactory dysfunction based on imaging. We designed this study to compare the subjective olfactory function differences and brain gray-matter (GM) and white-matter (WM) volume differences between patients with traumatic olfactory dysfunction and those with other types of olfactory dysfunction and to determine the characteristics of subjective olfactory dysfunction and imaging features in patients with traumatic olfactory disorders. The findings of this study can provide a theoretical basis for the diagnosis of traumatic olfactory disorders. This ethics committee-approved, retrospective case-control study included 56 patients with traumatic olfactory dysfunction (trauma group) and 45 patients with other types of olfactory dysfunction (e.g., postinfection, nasal inflammation, idiopathic disease). The "Sniffin' Sticks" olfactory function test was used to analyze the subjective olfactory function differences between the two groups, and voxel-based morphometry (VBM) was used to compare the GM volume (GMV) and WM volume (WMV) of brain regions between the two groups. (I) There was no statistical difference in age distribution between the trauma group (41.55±11.77 years) and the control group (38.87±14.37 years; P>0.05). (II) The trauma group had significantly lower total scores and subtest scores on the Sniffin' Sticks olfactory test compared to the control group [odor threshold test (OT): 1.04±0.33 vs. 1.67±1.42; odor discrimination test (OD): 2.93±2.25 vs. 5.42±3.66; odor identification test (OI): 2.77±1.94 vs. 6.71±3.55; total scores: 6.74±3.91 vs. 13.81±7.63; all P values <0.05]. (III) Compared with the control group, the trauma group had significantly reduced GMV and WMV in the bilateral orbitofrontal cortex, bilateral anterior cingulate gyrus, bilateral cingulate gyrus, bilateral rectus gyrus, bilateral olfactory cortex, right superior frontal gyrus, bilateral insula, bilateral caudate nucleus, and bilateral thalamus [Pfamily-wise error (FWE)<0.05]. (IV) There was a significant positive correlation between the odor identification function scores and GMV in certain brain regions (PFWE<0.05), and the GMV in these regions was reduced in the trauma group compared to the control group. Compared to patients with other types of olfactory dysfunction, patients with traumatic olfactory dysfunction have poorer subjective olfactory functions and more severe damage to olfactory-related brain regions, including the bilateral orbitofrontal cortex, anterior cingulate gyrus, cingulate gyrus, rectus gyrus, insula, and olfactory cortex. The olfactory nerve damage in these brain regions can be used as a basis for the diagnosis of traumatic olfactory disorders.

Using essential oils in rehabilitation of olfactory disorders in patients who have had a new coronavirus infection

Background. SARS-CoV-2 infection often results in olfactory disorder at different levels of the nervous system, which may persist as anosmia, parosmia, hyperosmia, hyposmia, cacosmia, and olfactory hallucinations after recovery.The aim. To study the effect of essential oils on the restoration of the olfactory apparatus in patients with coronavirus.Materials and methods. We examined 138 people (mean age 19.9 ± 7.05 years) with olfactory complaints, 60 of them underwent olfactory training with essential oils (EO) for 2 months. Olfactory function was assessed using the Hansen – Roseburg method before and after the training.Results. After 3 months of using essential oil sets for olfactory training, 27 respondents noted an improvement in the quality of odours and the appearance of previously missing odours. When conducting the Hansen – Roseburg test, a statistically significant improvement in the indicators for determining the tested odorants was revealed: phenylethyl alcohol (PA) – 7 [5; 7]; benzyl acetate (BA) – 6 [4; 6]; formic acid (FA) – 6 [2; 7] (p &lt; 0.05). When repeating the test in the control group of 30 people, only 4 respondents reported an olfaction improvement; the results of the olfactory assessment according to Hansen – Roseburg were as follows: PA – 5 [2; 6], BA – 4 [3; 5], FA – 2 [2; 4] (p &gt; 0.05).Conclusion. The data obtained after 3 months of olfactory training with a special set of essential oils and the subsequent olfactory testing indicate that olfactory training is a promising method for olfactory restoration, which can help many people regain the joy of perceiving odours and significantly improve their quality of life. The success of the method depends on the correct use of essential oils and compliance with the frequency of training.

Anterior piriform cortex dysfunction underlies autism spectrum disorders-related olfactory deficits in Fmr1 conditional deletion mice.

Previous studies indicated that ASD-related olfactory dysfunctions are rooted in the piriform cortex. However, the direct evidence supporting a causal link between the dysfunction of the piriform cortex and olfactory disorders in ASD is limited. In the present study, we explored the role of anterior piriform cortex (aPC) in ASD-related olfactory disorders by specifically ablating Fmr1, a leading known monogenic cause for ASD, in the pyramidal neurons. Our data demonstrated that the targeted deletion of Fmr1 in aPC pyramidal neurons was sufficient to induce deficits in olfactory detection. In vivo and in vitro electrophysiological recordings showed that the deletion of Fmr1 increased the activity of pyramidal neurons, exhibiting an enhanced excitatory response and a reduced inhibitory response upon odor stimulation. Furthermore, specific deletion of Fmr1 enhanced the power of beta oscillations during odor stimuli, meanwhile, disturbed excitatory and inhibitory synaptic transmission. The abnormal morphology of pyramidal neurons induced by the deletion of Fmr1 may be responsible for the impaired aPC neuronal function. These findings suggest that dysfunction of the aPC may play a role in olfactory impairments observed in ASD models related to Fmr1 deficiency.

The effectiveness of olfactory training for chronic olfactory disorder following COVID-19: a systematic review.

Chronic olfactory disorders are some of the most frequent post-COVID-19 presentations. Olfactory training (OT) is currently the most popular method used for treating post-viral olfactory dysfunction (PVOD). We evaluated the effect of olfactory training on the chronic olfactory disorders of patients infected with COVID-19. A systematic literature search was performed per PRISMA guidelines in PubMed, Scopus, Web of Science, EBSCOhost, and the Cochrane Library. Only patients with chronic olfactory disorders of 30 days or more were included. The primary outcome was the olfactory score at the end of follow-up. In all studies, improvement was defined as a positive change over time in the results of objective psychophysical olfactory tests. The most commonly used test was the Sniffin' Sticks. Typically, outcome measures involved comparing the mean olfactory scores. In the Sniffin' Sticks test, an improvement was also indicated by a change of 5.5 points or more in the Threshold, Discrimination, and Identification scores. Fourteen studies (1.596 participants) were included in this review. Among the included studies, up to 10 were RCTs. Nine studies assessed the combined effects of adjuvant therapy and olfactory training, while five studies assessed only OT. In our assessment, olfactory training alone produces significant improvements in chronic olfactory dysfunctions. However, a combined therapy approach is essential to achieve more effective outcomes. Integrating olfactory training with adjuvants like CoUltraPEALut, Cerebrolysin, and oral Vitamin A has demonstrated substantial benefits in enhancing post-COVID-19 olfactory function. Strict adherence to the OT protocol and extending the duration of OT to 3 months or more significantly enhance treatment outcomes.

Variants of persistent olfactory dysfunction associated with Novel Coronavirus infection and treatment results

The problem of the occurrence of persistent olfactory dysfunction (OD) associated with Novel Coronavirus infection (COVID-19) has now become relevant, however, a regulated standard of therapy has not been developed. According to the literature, about 60 % of patients report the presence of olfactory disorders that persist for several months or more after recovery from COVID-19. However, no more than 5 % seek medical help for olfactory disorders, which indicates the importance of the problem and the need for treatment in a polyclinic setting. Currently, two main areas of treatment for quantitative and qualitative disorders of the sense of smell are used – drug and non-drug therapy. The article proposes a systematization option based on existing treatment methods with an assessment of their effectiveness. The method of performing olfactory training is described, and the results of treatment of persistent OD are presented.