Clinical significance of olfactory event-related potentials related to orthonasal and retronasal olfactory testing

OBJECTIVE: The purpose of this study was to evaluate the likelihood of recording olfactory event-related potentials (OERPs) in patients with an olfactory dysfunction and to correlate the electrophysiological responses to orthonasal and retronasal olfactory testing. DESIGN/MATERIALS AND METHODS: This was a prospective study of 65 patients with different origins of their olfactory loss. Orthonasal olfactory function was assessed with the "Sniffin' Sticks" test (orthonasal score; maximal score 48) and retronasal olfactory function with odorized powders presented intraorally (retronasal score; maximal score 20). The OERPs were obtained after presentation of 2-phenyl ethyl alcohol, the selected olfactory stimulus. Causes of olfactory dysfunction included postinfectious olfactory loss (n = 15), head trauma (n = 26), nasal polyposis (n = 15), and mixed causes (idiopathic, toxic, drug induced) (n = 9). RESULTS: Based on orthonasal testing, 32 and 33 patients were diagnosed with anosmia and hyposmia, respectively. Twenty-two patients from the hyposmic group demonstrated reliable OERPs. No OERPs were recorded in the anosmic group. Prevalence of OERPs in a cohort of patients with olfactory dysfunction was 33.8% (22 of 65). Median score (expressed as the percentage of the maximal score that could be obtained theoretically) in which OERPs were recorded was 50% (24 of 48) with orthonasal testing and 80% (16 of 20) with retronasal testing. CONCLUSIONS: Patients with olfactory dysfunction usually demonstrate OERPs in one third of the cases. When olfactory dysfunction is in the range that separates normosmic subjects from anosmic patients, patients may have identifiable OERPs. Interpretation of both orthonasal and retronasal psychophysical olfactory testing should be supported by the recording of OERPs in a clinical setting.     

Euosmia: a rare form of parosmia

The nature of qualitative olfactory disorders such as phantosmia and parosmia is a matter of debate. Parosmia and phantosmia mainly occur in combination with post-traumatic or post-infectious olfactory loss. Rare causes of these disorders such as brain tumors, side-effects of drugs, paraneoplastic syndromes, psychiatric disorders or intracerebral haemorrhage have been reported. Parosmias are distorted sensations of smell elicited by an odor, whereas phantosmias persist permanently or occur without the presence of an odor source. Phantosmias differ widely in terms of their nature. In contrast, parosmias always seem to be unpleasant. We report the case of a female with post-infectious hyposmia who reported a pleasant parosmia to selected odorants. We have called this rare clinical presentation euosmia.     

Retronasal and orthonasal olfactory ability after laryngectomy

OBJECTIVE: To characterize orthonasal and retronasal olfactory ability in patients who have had a total laryngectomy (TL). DESIGN: Prospective psychophysical evaluation of orthonasal and retronasal olfactory function. SETTING: Academic center outpatient clinic. PATIENTS: Volunteer sample of 36 subjects who underwent laryngectomy 0.5 to 25.0 years after TL (median, 3.5 years) and 36 age-, sex-, and smoking history-matched controls. MAIN OUTCOME MEASURES: Scores on established psychophysical tests of orthonasal and retronasal olfaction and self-rating scores of smell assessed with a visual analog scale. RESULTS: Assessment of orthonasal olfactory ability yielded a mean composite score of 4.3 (maximum score, 7) for the TL group and 5.3 for the control group (P = .002). Evaluation of retronasal olfactory ability resulted in a mean score of 11.0 (maximum score, 20) for the TL group vs 14.3 for the control group (P<.001). The mean self-rating scores of smell were 2.9 and 6.6 (maximum score, 10) for the TL and control groups, respectively (P<.001). Self-ratings of smell positively correlated with orthonasal (r(S) = 0.42; P<.001) and retronasal (r(S) = 0.50; P<.001) olfactory ability. CONCLUSIONS: Laryngectomy is associated with measurable decreases in olfactory function that are also subjectively perceived. Quantification of decrements in orthonasal and retronasal olfactory function can be used to characterize the severity of hyposmia and to assess the potential for, and efficacy of, olfactory rehabilitation. Although self-assessment with a simple visual analog scale successfully identifies many laryngectomy patients who have objective evidence of olfactory dysfunction, further investigation is necessary to evaluate and compare its validity and reliability with other available survey instruments that purport to measure olfaction.     

Olfactory dysfunction in patients with head trauma.

OBJECTIVE: There are few reports about following up olfactory acuity of the patients who have post-traumatic olfactory dysfunction. In this study, we studied about patients with post-traumatic olfactory dysfunction for a short period under a treatment. METHODS: The olfactory function of 27 patients with head trauma was studied. The olfactory acuities of all the patients were examined using olfactory tests before the treatment, and 18 patients were examined again after the treatment. Olfactory functions were evaluated in 26 patients by T&T olfactometry and in 27 patients by Alinamin test. All of the patients were treated with a local injection of suspended steroid solution into the nasal mucosa [J Otolaryngol Jpn 102 (1999) 1175]. RESULTS: Before the treatment, 16 patients (61.5%) presented anosmia, five patients (19.2%) presented severe hyposmia, three patients (11.5%) presented moderate hyposmia, and two patients (7.7%) presented mild hyposmia. Eighteen cases (69.2%) were negative for the Alinamin test and eight cases (30.8%) were positive. The improvement rates of recognition and detection thresholds by T&T olfactometry were 35.3 and 23.5%, respectively. CONCLUSION: Olfactory dysfunction caused by head trauma can be recovered to a limited degree in some cases by the local injection of steroid within the relatively short period from the start of the therapy.     

Epidemiological aspects of olfactory dysfunction

PURPOSE: This study aimed at assessing the most common aetiological factors causing total or partial olfactory deficit and the statistical analysis of some clinical aspects. MATERIALS AND METHODS: 243 patients reporting alfactory dysfunction were enrolled in this STUDY: A case history was drawn up for each patient, and all of them underwent otolaryngology objective examination, including nasal endoscopy, paranasal sinuses CT-scan, and Utrecht method (GITU) based smell indentification test. RESULTS: Upper respiratory viral infections (40.2%), ceanial-facial traumas (39.3%), and rhinosinusal pathologies (6.3%) were the main aetiopathological factors indentified. A relevant number of case were recorded with unknown aetiology (14.2%). In 2 cases, olfactory dysfunction was due to neurological diseases, in 1 case it was due to intoxication and, in another case, it was congenital. The correlation between aetiology, gender, age, symptoms duration and deficit severity was studied. CONCLUSIONS: many different aetiological factors caused the loss or weakening of the sense of smell. They mainly affected olfactory neurosensorial structures and odorant conduction. However, there were many cases of unknown aetiology. Women, over 40 in particular, were the most affected. Anosmia and severe hyposmia were mainly correlated with traumas and viral pathologies.     

Clinical assessment of retronasal olfactory function

OBJECTIVES: To develop a test kit for the simple assessment of retronasal olfactory function and to compare orthonasal and retronasal olfactory function in healthy subjects and patients with olfactory disorders. DESIGN AND PATIENTS: We tested 230 individuals with normosmia, hyposmia, and anosmia using grocery-available powders. Initially, 30 different substances were investigated. Subjects identified each substance using a list with 4 verbal items (forced choice). After preliminary experiments, 20 items were selected according to the degree to which they were identified by normosmic and anosmic subjects. Orthonasal olfactory function was assessed psychophysically using "sniffin' sticks," which includes tests for odor identification, discrimination, and butanol odor thresholds. In addition, anosmia was confirmed electrophysiologically by means of olfactory-evoked potentials. RESULTS: In healthy subjects, there was a test-retest reliability correlation of r(27) = 0.76 for retronasal olfactory function, which is similar to other odor identification tests. Retronasal testing in normosmic subjects allowed for the discrimination of sex-related differences, with women scoring higher than men (P =.007), and the identification of a slight decrease with age (r(120) = -0.20; P =.03). Orthonasal and retronasal identification of odors was found to correlate (r(86) = 0.78; P<.001). Retronasal testing allowed for the discrimination between normosmia, hyposmia, and anosmia (P<.001). In addition, retronasal performance of anosmic patients appeared to improve with duration of anosmia (P =.03). No difference was found between patients with anosmia of different origin. CONCLUSION: Results of the present investigation indicate that the assessment of retronasal olfactory function is possible using oral stimulus presentation.     

Differences between orthonasal and retronasal olfactory functions in patients with loss of the sense of smell

OBJECTIVE: To investigate differences between orthonasal and retronasal olfaction in patients with loss of the sense of smell without taste complaints. DESIGN: Electrophysiological and psychophysical testing of orthonasal and retronasal olfactory functions. SETTING: Outpatient clinics. PATIENTS: A series of 18 patients who had olfactory loss due to various reasons but no "taste" complaints. MAIN OUTCOME MEASURES: Orthonasal and retronasal olfactory functions assessed by olfactory event-related potentials and psychophysical smell tests. RESULTS: Psychophysical testing revealed retronasal olfaction to be normal or slightly altered, whereas orthonasal olfaction was either absent or severely compromised. Findings from nasal endoscopic examinations and computed tomographic scans were within the reference range in all subjects. In response to orthonasal stimulation there were neither detectable olfactory event-related potentials nor any with small amplitudes, whereas olfactory event-related potentials in response to retronasal stimulation were clearly present in some patients. CONCLUSION: These clinical observations, together with the psychophysical and electrophysiological findings, suggest that orthonasal and retronasal olfaction might be processed differently.     

上呼吸道感染后嗅觉障碍患者脑形态学与嗅觉功能相关性分析

目的 通过探究上呼吸道感染后嗅觉障碍脑灰质形态变化,得出上呼吸道感染后嗅觉障碍患者嗅觉中枢结构的影像学特点。方法 选取上呼吸道感染后嗅觉障碍的患者24例与嗅觉功能正常的健康对照受试者20例,通过基于体素的大脑皮质形态学体积测量(VBM)比较患者的大脑灰质和白质体积与对照组的差异。结果 上呼吸道感染后嗅觉障碍组患者TDI[气味察觉阈(T)、气味辨别能力(D)、气味识别能力(I)]总分(16.45±5.62)分,T为(2.33±0.93)分,D为(6.54±2.60)分,I为(7.58±3.22)分;嗅觉障碍平均时长为(19.00±6.33)个月;视觉模拟量表评分(VAS)为(7.79±2.41)分,与对照组比较均存在统计学差异(P<0.05)。上呼吸道感染后嗅觉障碍患者的大脑灰质总体积和嗅皮质体积明显小于对照组(P<0.05),大脑灰质总体积占全脑体积的比例和皮质厚度与嗅觉功能评分TDI值呈正相关(r=0.71,P<0.000 1;r=0.69,P=0.000 9)。结论 上呼吸道感染后嗅觉障碍患者大脑灰质总体积和嗅皮质体积减少,且嗅觉功能与大脑灰质体积比例及皮质厚度呈...     

Resfriado-gripe: pérdida grave del olfato a largo plazo

IntroductionIn the general population, we can find 2-3% of lifelong olfactory disorders (from hyposmia to anosmia). Two of the most frequent aetiologies are the common cold and flu. The aim of this study was to show the degree of long-term olfactory dysfunction caused by a cold or flu.MethodsThis study was based on 240 patients, with olfactory loss caused only by flu or a cold. We excluded all patients with concomitant illness (66 patients), the rest of patients (n = 174) consisted of 51 men (29.3%) and 123 women (70.7%). They all underwent olfactometry study (i and v cranial nerve) and a nasal sinus computed tomography scan, as well as magnetic resonance imaging of the brain. Results were compared with a control group (n = 120).ResultsVery significant differences in levels of olfactory impairment for the olfactory nerve (P < .00001) and trigeminal nerve (P < .0001) were confirmed.ConclusionsPeople that suffer olfactory dysfunction for more than 6 months, from flu or a cold, present serious impairment of olfactory abilities.     

Relationship between progression of type 2 diabetes mellitus and olfactory function

ObjectivesIn the literature, diabetes mellitus was mentioned as one of the etiologic factors of olfactory disorder. However, association between olfactory dysfunction and complications of type 2 diabetes mellitus is unclear. The aim of this study was to determine if there is any correlation between olfactory dysfunction and complications of diabetes mellitus.MethodsThe study population included eighty-five (85) patients with type 2 diabetes mellitus (56 females and 29 males, mean age 55.4 ± 9.4 years). The routine laboratory and ophthalmoscope examinations were used in the study. The Connecticut Chemosensory Clinical Research Center odor test was performed to all patients. Patients were grouped (normal, anosmia, mild hyposmia, moderate hyposmia, severe hyposmia) in respect to olfactory function.ResultDistribution of the patients was 34.1% male (29) and 65.9% female (56). Mean Hemoglobin A1c value was 9.0 ± 2.7. The distribution of complications was 38.8% nephropathy, 25.9% retinopathy, 24.7% microalbuminuria. In Odor Test classification, statistically significant difference was not detected in nephropathy, retinopathy and microalbuminuria ratios (p = 0.523, p = 0.057, p = 0.993).ConclusionsThis study revealed that in odor test classification, statistically significant difference was not detected between the patients with complications (nephropathy, retinopathy, and microalbuminuria) and the patients without complications.     

Incomplete and late recovery of sudden olfactory dysfunction in COVID-19

IntroductionSudden olfactory dysfunction is a new symptom related to COVID-19, with little data on its duration or recovery rate.ObjectiveTo characterize patients with sudden olfactory dysfunction during the COVID-19 pandemic, especially their recovery data.MethodsAn online survey was conducted by the Brazilian Society of Otorhinolaryngology and Cervico-Facial Surgery, and Brazilian Academy of Rhinology, including doctors who assessed sudden olfactory dysfunction patients starting after February 1st, 2020. Participants were posteriorly asked by e-mail to verify data on the recovery of sudden olfactory loss and test for COVID-19 at the end of the data collection period.Results253 sudden olfactory dysfunction patients were included, of which 59.1% were females with median age of 36 years, with a median follow-up period of 31 days. 183 patients (72.3%) had been tested for COVID-19, and of those 145 (79.2%) tested positive. Patients that tested positive for COVID-19 more frequently showed non-specific inflammatory symptoms (89.7% vs. 73.7%; p = 0.02), a lower rate of total recovery of sudden olfactory dysfunction (52.6% vs. 70.3%; p = 0.05) and a longer duration to achieve total recovery (15 days vs. 10 days; p = 0.0006) than the ones who tested negative for COVID-19. Considering only positive-COVID-19 patients, individuals with sudden hyposmia completely recovered more often than the ones with sudden anosmia (68.4% vs. 50.0%; p = 0.04).ConclusionPositive-COVID-19 patients with sudden olfactory dysfunction showed lower total recovery rate and longer duration than negative-COVID-19 patients. Additionally, total recovery was seen more frequently in positive-COVID-19 patients with sudden hyposmia than the ones with sudden anosmia.     

The olfactory function in patients with common variable immunodeficiency

AimsTo determine the incidence of olfactory dysfunction in common variable immunodeficiency patients. To evaluate the correlation between olfactory dysfunction and chronic rhinosinusitis in this class of patients.Materials and methodsFifty patients, with a diagnosis of common variable immunodeficiency and under immunoglobulin replacement therapy, were submitted to an otolaryngology physical examination and a CT scan of the craniofacial structures in order to show the presence of signs of chronic rhinosinusitis. An olfactory function evaluation was executed using the Sniffin’ Sticks Test, with assessment of olfactory threshold, discrimination, identification and overall composite scores (TDI: threshold-discrimination-identification score).ResultsAn olfactory dysfunction was found in 23 (46%) common variable immunodeficiency patients, with hyposmia and anosmia respectively present in 65% and 38% of them. The mean TDI score in the study group was 27.7. Common variable immunodeficiency patients with CRS presented a more suggestive increase of the olfactory threshold, discrimination and identification compared to those without chronic rhinosinusitis.ConclusionIn conclusion, patients with common variable immunodeficiency seem to suffer from olfactory disorders more than healthy people. One of the causal factors could be considered the presence of rhinosinusal pathologies.     

Clinical features of olfactory dysfunction in elderly patients

ObjectiveThis study aimed to investigate the causes of olfactory dysfunction (OD) and to discuss the benefits of understanding the characteristics of OD in elderly patients.MethodsA total of 4300 patients with OD who were treated at our hospital between January 1996 and December 2020 were retrospectively analyzed. There were 1833 men and 2467 women, with ages ranging from 4 to 95 years. The patients were divided into two groups: younger (less than 65 years old, n = 2947) and elderly (65 years old or more, n = 1353) groups. Causative diseases were chronic rhinosinusitis (CRS), post-viral (PV), post-traumatic (PT), central nervous system dysfunction (CNS), peripheral nervous system dysfunction (PNS), congenital, psychogenic, and unknown. Visual analogue scale (VAS) and olfactory detection and recognition thresholds using the T&T olfaction test were used to evaluate olfaction. The mean detection and recognition thresholds, as well as the deviation difference (the difference between the mean detection and recognition thresholds) were compared by causative disease.ResultsThe causative diseases in elderly group were CRS (32%), PV (28%), PT (3%), CNS (2%), and PNS (4%). OD of unknown cause was significantly more in elderly (30%) than in younger patients (12%). Olfactory detection and recognition thresholds in elderly group were significantly worse than in younger group (p < 0.05). The olfactory detection and recognition thresholds were not any significant differences between patients with OD of unknown cause and those with CNS.ConclusionOD of unknown cause was predominantly observed in elderly group. The olfactory acuity of OD of unknown cause was similar to CNS OD. These findings suggest the importance of continuous follow-up due to the potential of neurodegenerative diseases in elderly OD patients.     

Screening of Olfactory function Using the Biolfa® Olfactory Test: Investigations in Patients with Dysosmia

Objective —To present a statistical evaluation of a new olfactory test, Biolfa^®.

Material and Methods —The olfactory test was carried out in individuals with normal olfactory function (n=67; 31 males; mean age 27.4 years) and in patients with mild, moderate or severe hyposmia (n=155; 61 males; mean age 54.6 years). The main diagnoses of the hyposmic patients were upper respiratory tract infection (32%), nasal polyposis (24%), head trauma (8%), idiopathic (8%), old age (5%) and chronic rhinitis (5%). In the first part of the test, olfactory thresholds were measured for three different substances (eugenol, aldehyde C14 and phenyl ethyl alcohol). The second part comprised an odor identification test for determining olfactory function for a large panel of common odors of Southern European countries.

Results —Mean olfactory thresholds were determined for subjects with normal olfaction and hyposmic patients; there was a statistically significant relationship between olfactory thresholds and degree of olfaction (mild to moderate hyposmia versus severe hyposmia). For the odor identification test, a global score was determined to allow the differentiation of normosmic subjects from patients with mild, moderate or severe hyposmia. The principles of decision theory (i.e. analysis of the receiver operating characteristic curve) were applied to the problem of evaluating the ability of Biolfa to distinguish subnormal subjects from hyposmic subjects.

Conclusion —This study provides a basis for the routine clinical use of Biolfa.     

Main causes and diagnostic evaluation in patients with primary complaint of olfactory disturbances

IntroductionEstablishing a diagnosis in patients with olfactory disturbances has always been challenging for physicians.One reason for this is the rarity of some of the diseases that affect this sense, such as Kallmann's syndrome and post-viral olfactory loss.ObjectiveTo identify the major causes of olfactory disturbances and to describe the diagnostic evaluation in outpatients attended to at an ambulatory clinic specialized in olfaction disorders.MethodsA retrospective analysis was performed in outpatients with primary olfactory complaint attended to between June 1, 2011 and September 30, 2013 in a center specialized in olfactory disorders. Patient history, nasofibroscopy, and the University of Pennsylvania Smell Identification Test (UPSIT) comprised the examination.ResultsSixty-two patients were evaluated. The major causes were chronic rhinosinusitis (31%); rhinitis, primarily the allergic type (19%); post-viral olfactory loss (13%); and post-traumatic loss (8%). UPSIT scores were statistically different among different etiologies (p = 0.01).ConclusionsThe major diagnoses that should be part of the physician assessment when a patient complains of olfactory disturbance are chronic rhinosinusitis with and without polyps, allergic rhinitis, post-viral olfactory loss, and post-traumatic loss.     

Drug-induced olfactory and gustatory dysfunction: Analysis of FDA adverse events reporting system

ObjectivesWith the COVID-19 pandemic, there is growing interest and research in olfactory and gustatory dysfunction (OGD). Drug-induced dysfunction is an often overlooked etiology. While several medications include smell or taste disturbance as a side effect, there are no publications describing which medications are most frequently implicated. We aim to describe the patterns of these adverse drug reactions (ADRs) using the FDA Adverse Events Reporting System (FAERS).MethodsThe FAERS database was queried from 2011 to 2021 for terms describing ADRs related to OGD. Terms included anosmia, hyposmia, olfactory test abnormal, olfactory nerve disorder, hallucination olfactory, parosmia, ageusia, hypogeusia, dysgeusia, and taste disorder. We identified the top reported medications associated with general smell dysfunction, general taste dysfunction, reduced smell, and altered smell.ResultsFrom 2011 to 2021, 16,091 ADRs were reported with OGD, of which13,641 (84.8%) and 2,450 (15.2%) were associated with gustatory and olfactory reactions, respectively. Zinc products (370 reports) and fluticasone propionate (214) were most commonly associated with olfactory dysfunction, specifically reduced olfaction. Varenicline (24) and fluticasone propionate (23) were most commonly associated with altered smell. Lenalidomide (490) and sunitinib (468) were most commonly associated with gustatory dysfunction. Antineoplastic and immunomodulating medications accounted for 21.6% and 36.3% of olfactory and gustatory ADRs, respectively. Among this category, immunoglobulin drugs were the most commonly associated with OGD ADRs.ConclusionGustatory dysfunction is more commonly reported ADR compared with olfactory dysfunction. Immunologic/rheumatologic medications are the leading culprit of reported OGD. With increasing numbers of patients presenting to otolaryngologists for OGD, it is important to consider drug-induced etiology.Level of evidenceIII.     

Correspondence Between Three Olfactory Tests and Suprathreshold Odor Intensity Ratings

Objectives —The capability of three olfactory tests (European Test of Olfactory Capabilities, Sniffin’ Sticks and Cross-Cultural Smell Identification Test) to similarly classify subjects as normosmics, hyposmics and anosmics as well as the relation between test performance and suprathreshold ortho- and retronasal odor intensity ratings were examined.

Material and Methods —A total of 48 subjects (age range 15–84 years; mean age 49.5 years) completed the 3 olfactory tests, rated aqueous solutions of vanilla (0–0.31%) and lemon aroma (0–0.17%) for odor and flavor intensity and filled in a background questionnaire. Ten subjects had case histories indicating anosmia, with the remainder having subjectively normal olfaction.

Results —The test results were highly correlated and differentiated anosmic, hyposmic and normosmic subjects. At an individual level, some discrepancy was seen in the olfactory diagnoses given by the three tests. In principal component analysis, olfactory measurements were loaded on three components: (i) odor detection, discrimination and identification; (ii) suprathreshold intensity ratings; and (iii) threshold for n-butanol. Advanced age was related to impaired olfactory performance.

Conclusions —Although the three olfactory tests diagnosed the individuals slightly differently, all were considered to be valid for clinical evaluation of olfactory capabilities. The tests separated anosmics and normosmics highly significantly, and permitted an assessment of hyposmia. The suprathreshold odor intensity ratings reflected a different dimension of olfaction than the three olfactory tests.     

Relationship between cognitive impairment and olfactory function among older adults with olfactory impairment

ObjectiveUnderstanding the relationships among aging, cognitive function, and olfaction may be useful for diagnosing olfactory decline in older adults. Olfactory function declines in the early stage of neurodegenerative diseases, including Alzheimer's and Parkinson's diseases. Aging and cognitive impairment are associated with olfactory decline. Moreover, the assessment of hyposmia and anosmia is paramount to the diagnosis of neurodegenerative diseases. We aimed to assess the relationships among aging, cognitive function, and olfaction in patients with olfactory impairment.MethodsThis observational study included 141 patients with olfactory deterioration who presented with dementia, mild cognitive impairment (MCI), age-related hyposmia, or postviral olfactory dysfunction (PVOD). The patients underwent T&T olfactometry, a self-administered odor questionnaire (SAOQ), a visual analog scale (VAS), and a Mini-Mental State Examination.ResultsT&T odor recognition thresholds decreased with aging (p < 0.01) and cognitive impairment (p < 0.08). The average T&T recognition thresholds were 5.1,4.6,4.2, and 3.7 in dementia, MCI, age-related hyposmia, and PVOD, respectively. Moreover, the average differences between the detection and recognition thresholds were 3.7, 2.8, 2.3, and 2.0 in dementia, MCI, age-related hyposmia, and PVOD, respectively. Hyposmia with dementia presented the highest recognition thresholds (p < 0.05) and the largest differences between the T&T detection and recognition thresholds, compared with age-related hyposmia and PVOD (p < 0.05). Hyposmia with dementia had the highest SAOQ and VAS scores compared with the other groups (p < 0.05).ConclusionThe possibility of dementia should be investigated in patients with hyposmia, including those with high T&T recognition thresholds, a large difference between the T&T detection and recognition thresholds, and high SAOQ and VAS scores.     

Characteristics of olfactory disorders in relation to major causes of olfactory loss

OBJECTIVE: To investigate the consequences of olfactory loss and explore specific questions related to the effect of duration of olfactory loss, degree of olfactory sensitivity, and cause of the olfactory loss. PATIENTS: A total of 278 consecutive patients with hyposmia or anosmia were examined. RESULTS: Causes of olfactory loss were categorized as follows: trauma (17%), upper respiratory tract infection (URI) (39%), sinonasal disease (21%), congenital anosmia (3%), idiopathic causes (18%), or other causes (3%). Our data suggest that (1) recovery rate was higher in URI olfactory loss than in olfactory loss from other causes; (2) likelihood of recovery seemed to decrease with increased duration of olfactory loss; and (3) the elderly are more prone to URI olfactory loss than younger patients. Regarding changes in quality of life (QoL), we found that (1) in most patients olfactory loss caused food-related problems; (2) loss in QoL did not change with duration of olfactory loss; (3) younger patients had more complaints than older ones, and women had more complaints than men; (4) complaint scores were higher in hyposmic patients than in anosmic patients; and (5) self-rated depression did not relate to measured olfactory function. CONCLUSIONS: Among many complaints of olfactory loss, the predominant ones were food related. This loss in QoL seemed to be of greater importance in younger than in older people, and women seem to be affected more strongly than men.