Frequency Of Olfactory Dysfunction Research Articles

Frequency of olfactory dysfunction in pregnant women with SARS-CoV-2 infection.

In patients with COVID-19, olfactory dysfunction and anosmia have been reported, which in pregnant women occur in up to 24.2 %. To know the frequency at which pregnant women with SARS-CoV-2 infection have olfactory dysfunction. Age, gestational age, temperature, presence of nasal constipation or rhinorrhea, myalgia, headache, cough or chest pain were asked. Whether patients perceived and identified the scent of grape juice, coffee powder and menthol was evaluated. Central tendency and dispersion measures, frequencies and percentages were used. Sensitivity, specificity, positive and negative predictive value were calculated. Mann-Whitney's U-test and contrast of proportions were used for comparisons between groups. There was a higher proportion of women with cough, headache, dyspnea, myalgia, odynophagia, rhinorrhea, chest pain, and anosmia in SARS-CoV-2-positive women. In patients without COVID-19, 88.9 % detected each one of the scents; only 31.8 % of the positive group detected grapes scent, 47.7 % coffee and 59.1 % menthol, which had the highest percentages of sensitivity (40 %), specificity (21 %), positive predictive value (59 %) and negative predictive value (11 %). Olfactory dysfunction occurs in a significant percentage of pregnant women with COVID-19.

Assessment of olfactory and gustatory functions in COVID-19 patients

Background/aimThis study aims to evaluate of olfactory and gustatory functions of COVID-19 patients and possible risk factors for olfactory and gustatory dysfunctions. Materials and methodsThe cross-sectional study included adult patients who were diagnosed with COVID-19 in Gazi University Hospital between April 2020 and June 2020. Volunteered patients participated in a survey in which olfactory and gustatory functions and various clinical information were questioned. Sinonasal Outcome Test-22 was also administrated to all patients.ResultsA hundred and seventy-one patients participated in this study. Olfactory and gustatory dysfunctions rates were 10.5% (n: 18) and 10.5% (n: 18), respectively. Patients without any symptom other than smell and taste dysfunctions were clustered as group 1 and patients who are clinically symptomatic were clustered as group 2. Olfactory dysfunction occurred in 8% of group 1 and 17.4% of group 2 (p = 0.072). Gustatory dysfunction rate of smokers was 19.7% and significantly higher than gustatory dysfunction rate of nonsmokers (5.5%) (p = 0.007). Twenty-seven-point-eight percent of the patients with olfactory dysfunction (n = 5) were male and 72.2% (n: 13) were female. Sex did not show significant effect on rate of olfactory dysfunction. Twenty-five patients participated in psychophysical olfactory function test. No participant reported olfactory dysfunction at the time of test. Of the participants, 64% (n: 16) were normosmic and 36% (n: 9) were hyposmic according to Sniffin’ Stick test. ConclusionOlfactory and gustatory dysfunctions are more common in patients who are clinically symptomatic than those diagnosed during contact tracing. Objective tests may show that frequency of olfactory dysfunction is greater than frequency of self-reported olfactory dysfunction.

Association of Olfactory and Pulmonary Function in Middle-Aged and Older Adults: The Korea National Health and Nutrition Examination Survey.

Objectives: To identify the relationship between pulmonary function and subjective olfactory dysfunction in middle-aged and older adults. Materials and Methods: We used Korea National Health and Nutrition Examination Survey data from 2010 to 2012 to analyze 6191 participants in their 50s or older. Results: The frequency of olfactory dysfunction was 6.8% among the subjects with normal pulmonary function tests, but was significantly more frequent in those diagnosed with restrictive (9.6%) or obstructive (10.1%) pulmonary function. Forced volume vital capacity, forced expiratory volume (FEV)1, FEV6, and peak expiratory flow were significantly lower in the olfactory dysfunction group. The risk of olfactory dysfunction was significantly associated with obstructive pulmonary function (odds ratio (OR) [95% confidence interval (CI)]: 1.449 [1.010–2.081]) after adjusting for confounders (sex, rhinitis, chronic rhinosinusitis, hypertension, dyslipidemia, education level, stress, depressed mood, and suicidal ideation). Conclusion: Middle-aged and older adults with obstructive pulmonary function had a higher incidence of subjective olfactory dysfunction than the normal pulmonary function group. Early olfactory testing may improve the quality of life of patients with obstructive pulmonary function.

Testing olfactory dysfunction in acute and recovered COVID-19 patients: a single center study in Italy

BackgroundOlfactory dysfunction in coronavirus disease 2019 (COVID-19) is common during acute illness and appears to last longer than other symptoms. The aim of this study was to objectively investigate olfactory dysfunction in two cohorts of patients at two different stages: during acute illness and after a median recovery of 4 months.MethodsTwenty-five acutely ill patients and 26 recovered subjects were investigated. Acute patients had a molecular diagnosis of COVID-19; recovered subjects had a positive antibody assay and a negative molecular test. A 33-item psychophysical olfactory identification test tailored for the Italian population was performed.ResultsMedian time from symptoms onset to olfactory test was 33 days in acute patients and 122 days in recovered subjects. The former scored a significantly higher number of errors at psychophysical testing (median [IQR]: 8 [13] vs 3 [2], p < 0.001) and were more frequently hyposmic (64% vs 19%, p = 0.002). Recovered subjects reported a variable time to subjective olfactory recovery, from days up to 4 months. Participants included in the study reported no significant nasal symptoms at olfactory testing. Among recovered subject who reported olfactory loss during acute COVID-19, four (27%) were still hyposmic. Demographic and clinical characteristics did not show significant associations with olfactory dysfunction.ConclusionModerate-to-severe hospitalized patients showed a high level and frequency of olfactory dysfunction compared to recovered subjects. In the latter group, subjects who reported persisting olfactory dysfunction showed abnormal scores on psychophysical testing, indicating that, at least in some subjects, persistent hyposmia may represent a long-term sequela of COVID-19.

Frequency and Clinical Utility of Olfactory Dysfunction in COVID-19: a Systematic Review and Meta-analysis.

BackgroundOlfactory dysfunction (OD) has been gaining recognition as a symptom of COVID-19, but its clinical utility has not been well defined.ObjectivesTo quantify the clinical utility of identifying OD in the diagnosis of COVID-19 and determine an estimate of the frequency of OD amongst these patients.MethodsPubMed was searched up to 1 August 2020. Meta-analysis A included studies if they compared the frequency of OD in COVID-19 positive patients (proven by reverse transcription polymerase chain reaction) to COVID-19 negative controls. Meta-analysis B included studies if they described the frequency of OD in COVID-19 positive patients and if OD symptoms were explicitly asked in questionnaires or interviews or if smell tests were performed.ResultsThe pooled frequency of OD in COVID-19 positive patients (17,401 patients, 60 studies) was 0.56 (0.47–0.64) but differs between detection via smell testing (0.76 [0.51–0.91]) and survey/questionnaire report (0.53 [0.45–0.62]), although not reaching statistical significance (p = 0.089). Patients with reported OD were more likely to test positive for COVID-19 (diagnostic odds ratio 11.5 [8.01–16.5], sensitivity 0.48 (0.40 to 0.56), specificity 0.93 (0.90 to 0.96), positive likelihood ratio 6.10 (4.47–8.32) and negative likelihood ratio 0.58 (0.52–0.64)). There was significant heterogeneity amongst studies with possible publication bias.ConclusionFrequency of OD in COVID-19 differs greatly across studies. Nevertheless, patients with reported OD were significantly more likely to test positive for COVID-19. Patient-reported OD is a highly specific symptom of COVID-19 which should be included as part of the pre-test screening of suspect patients.

Clinical, Structural, and Neuropathological Features of Olfactory Dysfunction in Patients with Alzheimer's Disease.

We explored changes in clinical features and neuropathological mechanisms underlying olfactory dysfunction (OD) in 60 patients with Alzheimer's disease (AD). Olfactory function was evaluated using the Sniffin' Sticks test and a threshold discrimination identification (TDI) score. Based on the TDI score, we divided patients according to the presence or absence of OD (AD-OD and AD-NOD, respectively). Cognitive and neuropsychiatric symptoms were evaluated by a series of rating scales. The volumes and cortical thickness of the thalamus, hippocampus, and amygdala were measured using structural magnetic resonance imaging. Neuropathological protein levels in cerebrospinal fluid were measured. The frequency of OD was 50%. TDI scores were lower in the AD-OD group than in the AD-NOD group (p < 0.001). Compared with the AD-NOD group, the AD-OD group showed greater cognitive function impairments (p < 0.001), and daily living activities were more severely compromised (p = 0.019). The AD-OD group had lower hippocampal and amygdala volumes (p = 0.025, p = 0.030, respectively) and a more pronounced reduction in cortical thickness (p = 0.010). The total tau level was lower in the AD-OD group than the AD-NOD group (p = 0.040). Lower Mini-Mental State Examination scores and thinner AD-signature cortices were associated with lower TDI scores (OR = 0.826, p < 0.001; OR = 1.433, p = 0.008). Overall, in AD patients, the impairments in olfactory discrimination and identification seem to be more correlated with cognitive levels. OD in AD may be an indicator of pathological cognitive decline and structural changes.

Olfactory Dysfunction and Its Relationship with Clinical Symptoms of Alzheimer Disease.

Our study aimed to analyse the olfactory dysfunction (OD) evaluations between self-report, the Hyposmia Rating Scale (HRS) and the Sniffin’ Sticks test, and the relationship between OD and clinical features of AD. Sixty patients with AD dementia, 37 patients with mild cognitive impairment (MCI) due to AD and 30 healthy controls were consecutively recruited. Olfactory function was evaluated by self-report, HRS and Sniffin’ Sticks test. Patients were divided into AD with OD (AD-OD) and AD with no OD (AD-NOD) groups based on the results of the Sniffin’ Sticks test. Cognitive symptoms and neuropsychiatric symptoms were assessed by corresponding scales, and activities of daily living (ADL) were assessed by the ADL scale. In the control, MCI due to AD and AD dementia groups, the frequency of OD was 10.0%, 13.5% and 18.3%, respectively, by self-report; 6.7%, 24.3% and 48.3%, respectively, by HRS; and 3.3%, 13.5% and 65.0%, respectively, by the Sniffin’ Sticks test. Compared to the results of the Sniffin’ Sticks test, the diagnostic coincidence rates of OD by HRS in patients with MCI due to AD and AD dementia were 89.2% and 66.7%, respectively. Compared to the AD-NOD group, the scores of global cognition and memory, visuospatial ability and attention were all decreased (P<0.05), the apathy score was increased (P<0.05), and the ADL score was elevated (P<0.01). The frequency and accuracy of OD by self-report is relatively low. HRS can be used for screening olfaction in patients with MCI due to AD. The Sniffin’ Sticks test can be used for validating OD in AD patients. AD-OD patients have severe impairments in global cognition and multiple cognitive domains of memory, visuospatial ability and attention, as well as neuropsychiatric symptoms of apathy, and thus have seriously compromised ADL.

Olfactory Dysfunction in Older Adults is Associated with Feelings of Depression and Loneliness.

Olfactory dysfunction is a common complaint among physician visits. Olfactory loss affects quality of life and impairs function and activities of daily living. The purpose of our study was to assess the degree of odor identification associated with mental health. Olfactory function was measured using the brief smell identification test. Depressive symptoms were measured by the Center for Epidemiologic Studies Depression scale. Loneliness was assessed by the de Jong-Gierveld Loneliness Scale. Cognition was measured by a battery of 19 cognitive tests. The frequency of olfactory dysfunction in our study was ~40%. Older subjects had worse olfactory performance, as previously found. More loneliness was associated with worse odor identification. Similarly, symptoms of depression were associated with worse olfaction (among men). Although better global cognitive function was strongly associated with better odor identification, after controlling for multiple factors, the associations with depression and loneliness were unchanged. Clinicians should assess these mental health conditions when treating older patients who present with olfactory deficits.

Anosmia and olfactory outcomes following paediatric traumatic brain injury

Objective: Research into olfactory dysfunction (OD) following paediatric traumatic brain injury (TBI) is limited. The current study investigated the frequency of OD following paediatric TBI and the relationship between OD and injury characteristics including severity, site of impact and cause of injury. It was hypothesized that children with moderate/severe TBI would demonstrate greater OD than those with mild TBI.Design/method: Thirty-seven children aged 8–16 with TBI were recruited to a prospective longitudinal study at a metropolitan children’s hospital. Olfactory assessment, using the University of Pennsylvania Smell Identification Test, was completed at 0–3 months post-injury.Results: Nineteen per cent of participants demonstrated impaired olfaction, while a small number (5%) were anosmic. A significant relationship between OD and severity of injury was found. No other injury variables demonstrated a significant relationship with olfactory outcomes.Conclusions: OD was relatively common in this paediatric TBI cohort and the hypothesized relationship with severity of injury was supported. It is recommended that information about OD after TBI be routinely provided to children and families. Further research is needed in larger cohorts to support the implementation of routine clinical assessment, understand the relationship between OD and other injury characteristics, determine the functional implications of OD and document recovery trajectories.

Olfactory dysfunction in neuromyelitis optica spectrum disorders.

Few data were available for the understanding of olfactory function in neuromyelitis optica spectrum disorders (NMOSDs). The aims of our study were to investigate the incidence of olfactory dysfunction and characterize olfactory structures, using MRI, in patients with NMOSDs. Olfactory function was evaluated by olfactometer in 49 patients with NMOSDs and 26 matched healthy controls. MRI parameters such as olfactory bulb (OB) and the olfactory-related gray matter volume changes were assessed. The frequency of olfactory dysfunction was 53% in patients with NMOSDs. Olfactory detection thresholds were positively correlated with serum aquaporin-4 antibodies (fluorescent units) tested by fluorescent immunoprecipitation assay (FIPA) in NMOSDs (p = 0.009). Patients with olfactory dysfunction had smaller OB volume than did patients without olfactory dysfunction or controls (p < 0.01). Both detection and recognition thresholds for olfaction were negatively correlated with OB volume (p = 0.018, p < 0.01). The significant gray matter volume reduction in NMOSDs was found in the bilateral piriform cortex, orbitofrontal cortex, and parahippocampal gyri (FDR correction, p < 0.05, cluster size >200 voxels). Our data suggested that olfactory function deficits are prevalent in patients with NMOSDs. Reduced OB and olfactory-related cortex volume may be responsible for the olfactory dysfunction.