Hazardous events associated with impaired olfactory function

OBJECTIVE: To evaluate the risk of olfactory-related hazardous events in patients with impaired olfactory function. DESIGN: Retrospective cohort study. SETTING: A university-based clinic for smell and taste disorders. PATIENTS: A total of 445 patients who underwent olfactory testing between 1983 and 2001. INTERVENTIONS: Patient interview, olfactory testing. MAIN OUTCOME MEASURES: (1) Frequency of olfactory-related hazardous events including cooking incidents (ie, burning pots or pans), undetected fires, undetected gas leaks, and ingestion of spoiled foods or toxic substances; (2) level of olfactory function (anosmia; severe, moderate, or mild hyposmia; or normosmia) as determined by olfactory testing. RESULTS: Olfactory testing revealed that 76% of patients had some degree of impairment; 30% had complete anosmia. Thirty-seven percent of patients with olfactory impairment but only 19% of patients without impairment experienced at least 1 olfactory-related hazardous event. Of the hazardous events reported by impaired patients, cooking-related incidents were most common, representing 45%, with ingestion of spoiled food (25%), inability to detect a gas leak (23%), and inability to smell a fire (7%) reported less frequently. There was a significant correlation between frequency of hazardous events and degree of olfactory impairment (Cochran-Armitage trend test, P<.001): at least 1 hazardous event was reported by 45.2% of patients with anosmia, 34.1% with severe hyposmia, 32.8% with moderate hyposmia, 24.2% with mild hyposmia, and 19.0% of patients with with normal olfaction by testing. CONCLUSION: Patients with impaired olfactory function are more likely to experience olfactory-related hazardous events than those with normal olfactory function.     

Testing olfaction in a clinical setting

Assessment of olfactory functioning at the CCCRC entails a threshold test and an odor identification test that contains eight everyday items. A performance average on the two tests yields a composite score on a scale from 0 (anosmia) to 7 (normosmia). The performance of normal volunteers is stable over most of an individual's life span, but decreases for persons over the age of 65 years. Approximately half the patients with olfactory complaints display anosmia, and the other half have hyposmia. The distribution of scores, however, varies with etiologic category, emplified by the fact that patients with nasal/sinus disease display anosmia more frequently than hyposmia. The tests can determine cause (e.g., improvement of score with corticosteroid treatment in cases of nasal/sinus disease) and can also assess degree of improvement with treatment, such as sinus operation.     

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.     

Validation of the Connecticut olfactory test (CCCRC) adapted to Brazil

IntroductionOlfactory changes are quite common in the population, causing a significant impact on the quality of life. Documentation of the olfactory function is essential for the diagnosis, treatment and follow-up of patients with inflammatory diseases of the upper airways, neurodegenerative diseases or viral infections. Among the different existing smell tests, the CCCRC is an inexpensive test, easy to apply, but it has not yet been evaluated on a large scale in the Brazilian population.ObjectiveTo validate the CCCRC smell test, after adaptation for the Brazilian population, evaluating the performance of healthy volunteers and the stability of the test in retests.MethodsIn this study, we carried out a cultural adaptation of the CCCRC test to Brazil. To validate and determine the normality scores, we applied the test to 334 healthy volunteers, aged >18 years of age. The retest was also carried out in up to four weeks on 34 additional volunteers to assess validity of the results.ResultsWhen evaluating the participants’ performance, normosmia and mild hyposmia values were obtained in more than 95% of them. Women (58.4%) showed better accuracy than men (41.6%): p < 0.02, and individuals over 60 years of age showed worse performance (median: 6; 75^th percentile: 6.5; 25^th percentile). The test and retest of the 34 volunteers demonstrated that there was agreement (ICC, intraclass correlation coefficient) considered good in the left nostril (ICC = 0.65) and excellent in the right nostril (ICC = 0.77) in the combined score.ConclusionThe CCCRC test adapted to Brazil showed normal values, similar to the originally-described test and validations in other countries, with a high reproducibility rate. Considering the highly favorable cost-benefit ratio, the adapted CCCRC is a very useful tool for measuring olfactory function in the Brazilian population.     

Normal sense of smell in Kallmann syndrome. A case report

BACKGROUND: Kallmann's syndrome (KS) was first mentioned in 1944 as an association of anosmia and hypogonadotropic hypogonadism. Causes are multiple genetic defects the most common of which is the x-linked KS appearing mostly in men. However, autosomal dominant and autosomal recessive forms have also been described. PATIENT: We present a case of KS with normosmia (male, 39 years of age). All symptoms of hypogonadotropic hypogonadism were present. RESULTS: Psychophysical olfactory testing revealed left-sided anosmia with right-sided normosmia which was confirmed by electrophysiological measures of olfactory function. Magnetic resonance imaging indicated aplasia of the left olfactory tract and bulb, whereas the right-sided structures appeared to be normal. CONCLUSIONS: As indicated in this case with lateralized anosmia and contralateral normosmia, overall olfactory function strongly depends on the "best" nostril. Therefore, in many clinical situations, lateralized olfactory testing appears to be extremely important.     

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.     

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.     

Simple assessment of olfaction in patients with chronic rhinosinusitis

Conclusion: The brief-smell identification test (B-SIT) can substitute for the butanol threshold test (BTT) in screening of anosmia and postoperative assessment of olfactory outcomes in patients with chronic rhinosinusitis (CRS). A time-effective test battery composed of B-SIT and the visual analog scale (VAS) can be implemented for simple olfactory assessment in any otolaryngology clinic. Objectives: Anosmia is a distinct clinical entity requiring special attention. Unpredictable olfactory outcomes after surgery make preoperative assessment more important. We compared the results of the BTT, B-SIT, and VAS to investigate whether B-SIT or VAS can substitute for BTT in screening of anosmia and postoperative follow-up. Methods: We collected data on 68 CRS patients who had bilateral CRS and underwent endoscopic sinus surgery. Olfactory performance was graded using the BTT: normosmia, hyposmia, or anosmia. VAS and B-SIT were also performed. All tests were repeated 6 months after surgery. Postoperative improvement was defined by an increase of the BTT score ≥ 2. Results: The B-SIT and VAS scores of the anomics were significantly lower than those of the normosmics. B-SIT discriminated anosmia with high specificity. Within the improvement group, postoperative increase of B-SIT/VAS score showed significance. However, neither the B-SIT nor the VAS differentiated between no change and deterioration of olfaction.     

Correlation between olfactory severity ratings based on olfactory function test scores and self-reported severity rating of olfactory loss

Conclusion: Olfactory test scores are significantly correlated with self-rated severity scales. However, the statistical rating based on olfactory tests did not strongly agree with the self-reported severity rating. This suggests that there is a discrepancy between olfactory test results and the severity described by patients themselves.

Objectives: This study aimed to identify the correlation between statistical ratings based on test scores and self-rating of the severity of olfactory loss.

Method: A total of 1555 subjects were asked to rate olfactory loss severity by one of five scales. Olfactory tests consist of the butanol threshold test (BTT) and cross-cultural smell identification test (CCSIT).

Results: There were significant correlations between BTT scores and self-rated severity scales (r?=?0.619, p?r?=?0.597, p?p?p?相似文献   

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.     

The influence of olfactory loss on dietary behaviors

OBJECTIVES: To assess dietary behavior and possible changes in food selection in patients with smell loss. PATIENTS AND METHODS: A total of 176 patients (114 women and 62 men) age 17 to 86 years were classified into three diagnostic groups (normosmia, n = 12; hyposmia, n = 75; functional anosmia, n = 89) according to their olfactory test scores obtained with "Sniffin' Sticks." Group differences in food intake and dietary behaviors were investigated with a specifically designed questionnaire providing a dietary alterations score (DAS). RESULTS: Numerous dietary changes were reported, e.g., 29% of all patients reported that they eat less since the onset of olfactory dysfunction, 39% use more spices with their food, 47% go out to eat at restaurants less frequently, 37% eat less sweets, and 48% drink less sweet beverages. Subjects with weight gain or weight loss scored higher on the DAS scale than subjects who did not report changes in weight. Similarly, DAS scale changes were more pronounced in subjects with a gradual onset of olfactory loss compared to subjects with a sudden loss of olfaction. Finally, a change of taste preferences toward savory and salty foods was observed across all patients enrolled in the present study. CONCLUSIONS: Patients with olfactory loss report alterations of dietary behaviors. Numerous factors appear to impact the results of olfactory loss in terms of changes in diet.     

Applicability of the Scandinavian Odor Identification Test: A Finnish-Swedish Comparison

The possibility of using the Scandinavian Odor Identification Test (SOIT), developed for clinical purposes for use with Swedish subjects, for assessment of another northern European population was studied by comparing test performance between 127 Finnish and 127 Swedish participants, who were matched for age (19-85 years) and gender. The results showed very similar performance between countries and demonstrated, as expected, age- and gender-related differences in performance. Test-retest reliability was as good in Finnish as in Swedish subgroups of participants and no significant difference between countries in terms of diagnostic distribution (normosmia, hyposmia and anosmia) was found when using existing cut-off scores. The findings suggest that the SOIT, with its diagnostic cut-off scores, is reliable and valid for use with Finnish populations.     

The Scandinavian Odor-Identification Test: Development,Reliability, Validity and Normative Data

The Scandinavian Odor-Identification Test (SOIT) was developed to address the need for a culturally valid odor-identifi cation test for clinical use on the Scandinavian population that (i) has good ability to generalize performance to olfactory status, (ii) assesses olfactory and trigeminal function separately, (iii) requires only limited cognitive demands, (iv) has normative data and good sensitivity and specificity, and (v) is fast, easy to administer and inexpensive. Sixteen odorous test stimuli were selected that were relatively identifiable, familiar, strong in intensity and pleasant according to healthy participants. Four response alternatives were then selected for each test stimulus based on a confusion matrix of identification rates obtained from healthy participants, in a manner that controlled for task difficulty. Results on the SOIT from healthy persons and hyposmic patients showed satisfactory test-retest reliability, split-half reliability and validity. Cut-off scores for olfactory diagnosis (normosmia, hyposmia, anosmia) based on normative data obtained from 171 healthy persons showed a satisfactory sensitivity and specificity of the SOIT. Assessment of 22 anosmic patients with the SOIT revealed that three of the test stimuli were significant trigeminal stimulants.     

Applicability of the Scandinavian Odor Identification Test: a Finnish-Swedish comparison

The possibility of using the Scandinavian Odor Identification Test (SOIT), developed for clinical purposes for use with Swedish subjects, for assessment of another northern European population was studied by comparing test performance between 127 Finnish and 127 Swedish participants, who were matched for age (19-85 years) and gender. The results showed very similar performance between countries and demonstrated, as expected, age- and gender-related differences in performance. Test-retest reliability was as good in Finnish as in Swedish subgroups of participants and no significant difference between countries in terms of diagnostic distribution (normosmia, hyposmia and anosmia) was found when using existing cut-off scores. The findings suggest that the SOIT, with its diagnostic cut-off scores, is reliable and valid for use with Finnish populations.     

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.     

A new clinical olfactory function test: cross-cultural influence

OBJECTIVE: To investigate whether a new clinical olfactory test, the Odor Stick Identification Test for Japanese (OSIT-J), can be used to assess olfactory function cross-culturally in a US patient population. DESIGN: Cross-sectional prospective study. SETTING: A university medical center otolaryngology clinic. PATIENTS: Fifty US patients presenting with complaints of olfactory dysfunction from December 2004 to January 2006. INTERVENTIONS: Olfactory testing and patient interview. MAIN OUTCOME MEASURES: Comparison of test results obtained with the OSIT-J, the Connecticut Chemosensory Clinical Research Center (CCCRC) olfactory function test, and patients' self-reported level of olfactory function. Patients' opinions regarding the 2 test methods were also recorded. RESULTS: The mean +/- SD time required to administer the OSIT-J (8 +/- 1 minutes) was shorter than that required for the standard CCCRC test (21 +/- 6 minutes). Significant Spearman rank correlations were found between the OSIT-J and CCCRC test scores (r(s) = 0.80, P<.001, n = 50), and patients' self-reported level of olfactory function (r(s) = 0.73, P<.001, n = 50). Although 3 of the 13 odors used in the OSIT-J were not familiar to US subjects, patients reported that the OSIT-J was easier, more interesting, and the odors used more pleasant than the CCCRC test. CONCLUSIONS: Olfactory function tests developed in different countries should be evaluated to determine if a cross-cultural bias exists among test odorants. Although a cultural bias was detected for a few odorants, this study demonstrates that a modified version of the OSIT-J can be used to assess olfactory function in US patients.     

Anosmia after intranasal zinc gluconate use

BACKGROUND: Zinc is an essential mineral. Beneficial zinc absorption takes place via enteral, parenteral, or cutaneous routes. However, direct application to the olfactory epithelium has been reported to cause loss of smell. Recently, intranasal zinc gluconate has been recommended as a treatment for the common cold. Severe posttreatment hyposmia and anosmia have been observed. METHODS: The case report of a typical patient is presented and analyzed in detail, followed by a series of patients with severe hyposmia or anosmia after the use of intranasal zinc gluconate. RESULTS: Although interindividual variation in drug response and drug effect is apparent, the severe hyposmia or anosmia appears to be long lasting or permanent in some cases. The mechanism of olfactory loss is thought to be the direct action of the divalent zinc ion on the olfactory receptor cell. CONCLUSIONS: Zinc ions are toxic to olfactory epithelium. Reports of severe hyposmia with parosmia or anosmia have occurred after intranasal use of zinc gluconate.     

Lipoic acid in the treatment of smell dysfunction following viral infection of the upper respiratory tract

OBJECTIVES/HYPOTHESIS: The study aimed to investigate the potential therapeutic effects of alpha-lipoic acid in olfactory loss following infections of the upper respiratory tract. Possible mechanisms of actions include the release of nerve growth factor and antioxidative effects, both of which may be helpful in the regeneration of olfactory receptor neurons. STUDY DESIGN: Unblinded, prospective clinical trial. METHODS: A total of 23 patients participated (13 women, 10 men; mean age 57 y, age range 22-79 y; mean duration of olfactory loss, 14 mo; range, 4 to 33 mo); 19 of them were hyposmic and 4 had functional anosmia. Alpha-lipoic acid was used orally at a dose of 600 mg/day; it was prescribed for an average period of 4.5 months. Olfactory function was assessed using olfactory tests for phenyl ethyl alcohol odor threshold, odor discrimination, and odor identification. RESULTS: Seven patients (30%) showed no change in olfactory function. Two patients (9%) exhibited a moderate decrease in olfactory function; in contrast, six patients (26%) showed moderate and eight patients (35%) remarkable increase in olfactory function. Two of the 4 patients with functional anosmia reached hyposmia; 5 of 19 hyposmic patients became normosmic. Overall, this resulted in a significant improvement in olfactory function following treatment (P =.002). At the end of treatment parosmias were less frequent (22%) than at the beginning of therapy (48%). Interestingly, recovery of olfactory function appeared to be more pronounced in younger patients than in patients above the age of 60 years (P =.018). CONCLUSIONS: The results indicate that alpha-lipoic acid may be helpful in patients with olfactory loss after upper respiratory tract infection. However, to judge the true potential of this treatment, the outcome of double-blind, placebo-controlled studies in large groups of patients must be awaited, especially when considering the relatively high rate of spontaneous recovery in olfactory loss after upper respiratory tract infection.     

Identifying normosmics: a comparison of two populations

An olfactory function test developed by the Connecticut Chemosensory Clinical Research Center (CCCRC) was administered to 65 normal subjects to determine its ability to identify normosmic subjects. The CCCRC test categorizes individuals into five distinct levels of olfactory functioning according to composite score ranges derived from odor identification and butanol threshold subtests. These categories are: normosmic (normal); mildly, moderately, and severely hyposmic (impaired functioning); and anosmic (no sensation). Comparing score distributions from CCCRC with ours revealed that a greater percentage of our subjects were categorized as hyposmic because of higher butanol thresholds. The butanol threshold subtest was studied further to determine test-retest reliability and normal day-to-day variability in scores. Norms are the basis for interpreting test scores and are important in diagnosing and treating smell disorders.     

Can we smell without an olfactory bulb?

BACKGROUND: Lack of an olfactory bulb (OB) is typically associated with anosmia. METHODS: We present a patient with subnormal olfactory function in whom the OB could not be detected with magnetic resonance imaging (MRI). RESULTS: Olfactory function was evaluated on two occasions. Orthonasal olfactory function was assessed with the "Sniffin' Sticks" test providing a score equivalent to hyposmia. Retronasal olfactory function was studied with "smell powders" indicating a decreased, but not absence of, olfactory function. Importantly, chemosensory event-related potentials were clearly present in response to olfactory and trigeminal stimuli. CONCLUSION: This indicates that olfactory function may be present in some subjects even when an OB can not be detected with MRI.