Scandinavian Odor Identification Test Research Articles

Efficacy of the nasal airflow-inducing maneuver in the olfactory rehabilitation of laryngectomy patients: A systematic review and meta-analysis.

This is the first systematic review and meta-analysis to investigate the effectiveness of the nasal airflow-inducing maneuver (NAIM) in olfactory rehabilitation for total laryngectomy (TL) patients. We conducted a systematic literature search following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The inclusion criteria required that patients must have undergone a TL with subsequent NAIM training for at least 2weeks and olfactory evaluation. The impact of NAIM on olfactory outcomes compared to that at baseline was measured. Olfactory measures included the Sniffin' Sticks Test, Smell Disk Test, Scandinavian Odor Identification Test, and Quick Odor Detection Test. The primary outcome measures were the proportion of patients with normosmia at baseline and after intervention. Seven studies from 2000 to 2023 comprising a total of 290 TL patients met the inclusion criteria. The meta-analysis revealed that prior to intervention, the pooled proportion of patients with normosmia was 0.16 (95% confidence interval [CI]: 0.09‒0.27, p=0.01). After intervention, the same proportion increased to 0.55 (95% CI: 0.45‒0.68, p=0.001). Among the included patients, 88.3% were initially anosmic or hyposmic, which was reduced to 48.9% after NAIM practice, with 51.1% achieving normosmia. The percent improvement was not found to be significantly associated with the timing of intervention post-TL (p=0.18). NAIM increased the proportion of patients who achieved normosmia in TL patients. NAIM stands out as a safe, easily teachable maneuver with promising results. Further efforts are warranted to provide specific recommendations and guidelines for the use of NAIM in clinical practice.

PM2.5 and Dementia in a Low Exposure Setting: The Influence of Odor Identification Ability and APOE.

Growing evidence show that long term exposure to air pollution increases the risk of dementia. The aim of this study was to investigate associations between PM2.5 exposure and dementia in a low exposure area, and to investigate the role of olfaction and the APOE ɛ4 allele in these associations. Data were drawn from the Betula project, a longitudinal study on aging, memory, and dementia in Sweden. Odor identification ability was assessed using the Scandinavian Odor Identification Test (SOIT). Annual mean PM2.5 concentrations were obtained from a dispersion-model and matched at the participants' residential address. Proportional hazard regression was used to calculate hazard ratios. Of 1,846 participants, 348 developed dementia during the 21-year follow-up period. The average annual mean PM2.5 exposure at baseline was 6.77μg/m3, which is 1.77μg/m3 above the WHO definition of clean air. In a fully adjusted model (adjusted for age, sex, APOE, SOIT, cardiovascular diseases and risk factors, and education) each 1μg/m3 difference in annual mean PM2.5-concentration was associated with a hazard ratio of 1.23 for dementia (95% CI: 1.01-1.50). Analyses stratified by APOE status (ɛ4 carriers versus non-carriers), and odor identification ability (high versus low), showed associations only for ɛ4 carriers, and for low performance on odor identification ability. PM2.5 was associated with an increased risk of dementia in this low pollution setting. The associations between PM2.5 and dementia seemed stronger in APOE carriers and those with below average odor identification ability.

PM2.5 and dementia – APOE-ε4 and odor identification ability as moderators

BACKGROUND AND AIM: There is growing evidence that long term exposure to air pollution increases the risk of dementia. However, more research regarding possible moderators and mediators are needed in order to identify vulnerable populations, and to better understand the complicated pathways between air pollution and dementia. The aim of this study was to investigate 1) the associations between PM2.5 exposure and dementia incidence, and 2) the possible mediating or moderating role of APOE-ε4 and odor identification ability, two known risk factors of dementia. METHODS: Data was drawn from the Betula project, a longitudinal study on aging, memory, and dementia in Sweden. DNA was extracted via blood samples to allow for genotyping of the APOE gene. Odor identification ability was assessed using the Scandinavian Odor Identification Test (SOIT). Variation in within-city annual mean PM2.5 concentrations were obtained from a dispersion-model and matched at the participants’ residential address. Proportional hazard regression was used to calculate hazard ratios. RESULTS: Of 1846 participants, 348 developed dementia during the follow up period. Each 1 µg/m3 increase in annual mean PM2.5-concentration was associated with a hazard ratio of 1,24 for dementia (95% CI: 1,02–1,51). Both APOE status and odor identification ability acted as moderators, as in subsequent analyses, significant associations persisted only for APOE-ε4 carriers, and low performers on the SOIT. CONCLUSIONS: Locally emitted PM2.5 was associated with an increased risk of dementia in this moderately polluted setting. APOE-ε4 carriers, and those with below average odor identification ability were particularly vulnerable. KEYWORDS: Air pollution, Alzheimer’s disease, vascular dementia, apolipoprotein E, olfaction.

Smell Loss Predicts Mortality Risk Regardless of Dementia Conversion.

To determine whether dementia could explain the association between poor olfactory performance and mortality risk within a decade-long follow-up period. Prospective cohort study. Betula Study, Umeå, Sweden. A population-based sample of adult participants without dementia at baseline aged 40 to 90 (N = 1,774). Olfactory performance using the Scandinavian Odor-Identification Test (SOIT) and self-reported olfactory function; several social, cognitive, and medical risk factors at baseline; and incident dementia during the following decade. Within the 10-year follow-up, 411 of 1,774 (23.2%) participants had died. In a Cox model, the association between higher SOIT score and lower mortality was significant (hazard ratio (HR) = 0.74 per point interval, 95% confidence interval (CI) = 0.71-0.77, P < .001). The effect was attenuated, but remained significant, after controlling for age, sex, education, and health-related and cognitive variables (HR = 0.92, 95% CI = 0.87-0.97, P = .001). The association between SOIT score and mortality was retained after controlling for dementia conversion before death (HR = 0.92, 95% CI = 0.87-0.97, P = .001). Similar results were obtained for self-reported olfactory dysfunction. Poor odor identification and poor self-reported olfactory function are associated with greater likelihood of future mortality. Dementia does not attenuate the association between olfactory loss and mortality, suggesting that olfactory loss might mark deteriorating health, irrespective of dementia.

Olfactory function after total laryngectomy

Abstract The aim of this study was to assess the olfactory function in patients who underwent total laryngectomy. Olfactory function assessment using the Scandinavian Odor Identification Test was carried out in 32 patients who had undergone total laryngectomy and were being followed up in Kasr El Aini ENT Outpatient Clinic. The studied cases included both men (59%) and women (41%). Their ages ranged from 50 to 70 years. The duration between operation and olfactory assessment ranged from 4.5 to 15.5 months. Results showed 75% incidence for anosmia and 25% incidence for hyposmia. Both age and sex did not correlate with either pattern of olfactory loss. The mean duration between operation and olfactory assessment was statistically significantly different between those who developed hyposmia and those who developed anosmia, being longer in the latter group. There was also a linear relation between the number of odors that could be smelled and postoperative duration. The longer the duration, the fewer the number of odors that could be smelled. The study reviewed similar studies and discussed suggested explanations. The study also recommended preoperative olfactory assessment as well as postoperative olfactory rehabilitation for such patients.

Long-term episodic memory decline is associated with olfactory deficits only in carriers of ApoE-є4

The ɛ4 allele of the Apolipoprotein E gene is a genetic risk factor for late-onset dementia of the Alzheimers' type (DAT), which is characterized by loss of both episodic memory and olfactory functions. Little is known about the possible role of ɛ4 in the association between ongoing episodic memory decline and olfactory deficits in the general population, but such information is relevant in determining the relevance of olfaction as a marker of DAT risk. The present study was based on a large, population-based sample (n=1087, aged 45–90 years, of which 324 were ɛ4-carriers). Episodic memory change rates were established using data collected every 5 years for a 10–20 year interval leading up to an olfactory assessment using the Scandinavian Odor Identification Test at the last wave of data collection. Participants were classified according to whether or not their episodic memory ability declined more rapidly than the age-typical norm (by >1SD). Our main result is that only in ɛ4-carriers was episodic memory decline associated with odor identification impairment. In individuals without ɛ4, odor identification was unrelated to episodic memory decline status. Follow-up analyses indicated that this moderation by ɛ4 was due to the olfactory nature of the identification test, and that the effect was not caused by 63 individuals with dementia. Our results suggest that the ɛ4 determines the functional association between ongoing episodic memory decline and olfaction. These findings are consistent with the notion that ɛ4-carriers with DAT, compared to non-carriers, display a cortical atrophy pattern that is more focused on mediotemporal lobe regions supporting olfactory and episodic memory functions. Olfactory and memory assessments might provide complementary information on mediotemporal atrophy prior to clinical dementia onset, but the ɛ4 should be considered when using olfactory assessment as an early-stage indicator.

Longitudinal Changes in Familiarity, Free and Cued Odor Identification, and Edibility Judgments for Odors in Aging Individuals.

This longitudinal study investigated changes in olfaction as assessed by a set of tasks requiring different aspects of semantic information in normal aging individuals. Using 16 odorous items from a standardized olfactory test, the Scandinavian Odor Identification Test, 107 middle aged and older adults were assessed up to three times over a period of 6.5 years, requesting them to rate familiarity and edibility for each odorous item before identifying it with or without presenting verbal cues. Using linear mixed models, the longitudinal analyses revealed significant correlations between all olfactory measures. Furthermore, we found an almost parallel age-related decline in all olfactory tasks, although free identification performance indicated a trend toward faster decline with age. Women showed less decline compared with men, in particular for edibility judgments. The results corroborate earlier cross-sectional findings showing significant correlations between the olfactory tasks. In the present study of healthy middle-aged and older adults, we found a parallel longitudinal decline across different tests of olfaction.

Even cognitively well-functioning adults are unaware of their olfactory dysfunction: Implications for ENT clinicians and researchers.

Past findings of an impact of cognitive impairment on awareness of olfactory dysfunction, and high prevalence of age-associated cognitive impairment motivated the present study of whether middle-aged and elderly adults are unaware of an olfactory dysfunction despite being carefully screened for cognitive impairment. The sample included 203 Norwegian participants, aged 46-79 years, 134 women and 69 men, who underwent comprehensive neuropsychological assessment for screening of cognitive impairment. Subjective assessment of olfactory function ("How would you estimate your sense of smell?") was compared with outcome on objective assessment of olfactory function with the Scandinavian Odor Identification Test, which in the present study was shown to be valid for use on Norwegian populations. We found that 79% of this cognitively healthy sample with objectively assessed olfactory dysfunction reported normal olfactory function (57% of functionally anosmics reported normal function). In contrast, only 9% with objectively assessed normal olfactory function reported olfactory dysfunction. A large proportion of cognitively well-functioning middle-aged and elderly adults with an olfactory dysfunction are unaware of their dysfunction. The ENT physician who suspects that the sense of smell may be compromised should, in addition to an anamnesis, assess the patient`s olfactory function objectively.

Odor identification and cognitive abilities in Alzheimer’s disease

Abstract Research results indicate systemic odor identification deficits in patients with Alzheimer’s disease (AD). The aims of this study were: 1) to compare the ability to identify different odors and to compare cognitive status among patients with AD, patients with vascular dementia (VaD) and a comparison group of elderly persons; 2) to test the efficiency of olfactory and neuropsychological measures to classify patients and 3) to relate the odor identification ability with cognitive functioning for each group, respectively. The participants were 15 patients with AD, 11 patients with VaD and 30 non-demented elderly persons, age range 58 to 90. To assess olfactory function, we used the Scandinavian Odor-Identification Test. To assess cognitive functions, we used the Dementia Rating Scale-2, the Clock Drawing Test, the Boston Naming Test and the Category Fluency Test. The ANOVA showed that patients with AD correctly identifed significantly fewer odors presented to them compared to patients with VaD and control group. Patients with AD achieved significantly lower scores on all neuropsychological measures compared to the control group and differ in the DRS-2 total score, initiation/perseveration, constructive and naming abilities comparing to patients with VaD. Discriminant analysis showed that category fluency and olfactory identification were the best predictors of AD. Significant correlations were found between the olfactory and initiation/perseveration, memory and animal naming abilities for patients with AD. Differences among patients with AD, VaD and elderly persons exist in their abilities to identify odors. The findings suggest that olfactory functional testing in combination with memory testing are important.

Initial size of cleft does not correlate with size and function of nasal airway in adults with unilateral cleft lip and palate

The noses of patients with clefts are often functionally inadequate. The aim of the present study was to evaluate the correlation between size of the maxillary cleft in infancy and size and function of the nasal airway in adults with unilateral cleft lip and palate (UCLP). This is a long-term follow up study including 53 patients with UCLP born between 1960 and 1987 and treated at the Cleft Lip and Palate Centre, Uppsala University Hospital, Sweden. Lip repair was performed at 3–4 months of age followed by either a one-stage or a two-stage palatal closure. The size of the cleft was measured on infant maxillary dental casts. Nasal minimum cross-sectional area (cm2) and volume (cm3) (acoustic rhinometry), air flow resistance (Pa s/cm3) (rhinomanometry), peak inspiratory flow (l/min) (peak nasal inspiratory flow) and number of identified odours (Scandinavian odor-identification test) were assessed in adulthood. The size of the maxillary cleft varied considerably at infancy. The size of the nasal airway and its function on the cleft side in adulthood were reduced compared with the non-cleft side, but no correlations were found between size of the initial cleft in infancy and size and function of the nasal airway in adulthood. In adults born with UCLP, therefore, size of the maxillary cleft in infancy does not seem to affect size and function of the nasal airway in adulthood.

Unawareness of Olfactory Dysfunction and its Association with Cognitive Functioning in Middle Aged and Old Adults

The objective of this study was (a) to investigate the accordance of self-reported and objectively assessed olfactory functioning and (b) to compare performance on cognitive tests of individuals unaware of their olfactory dysfunction with individuals aware of their olfactory status. Two hundred forty participants, constituting two age groups, were evaluated with the Scandinavian Odor Identification Test, a question of self-evaluated olfactory function, tests of cognitive function, and a memory questionnaire. The proportion of individuals being unaware of an olfactory dysfunction was high in both middle aged (86%) and old (78%) participants. Performance on neuropsychological tests showed that persons unaware of their olfactory dysfunction performed poorer on tests of verbal learning and memory and attention/processing speed compared to individuals aware of a normal olfactory status as well as individuals aware of their olfactory dysfunction. The clinical relevance of unawareness of olfactory dysfunction, as suggested earlier, needs further investigation and stresses the need of an extensive multi-modal and longitudinal assessment of unawareness of sensory and cognitive function to learn more about the facets of the concept of unawareness.

Rehabilitation of Smell after Total Laryngectomy

Rehabilitation of Smell after Total Laryngectomy

Objective Assessment of the Nasal Airway in Unilateral Cleft Lip and Palate—A Long-Term Study

To objectively evaluate the nasal function in adults operated on for unilateral cleft lip and palate with one-stage or two-stage palate closure. The population consists of all unilateral cleft lip and palate patients born from 1960 to 1987 and treated at the Cleft Lip and Palate Center, Uppsala University Hospital, Sweden. The patients were treated according to the same protocol except for palate closure, which was performed in one stage until 1977 and in two stages thereafter. Eighty-three patients participated. Mean follow-up time after primary surgery was 32 years. An age-matched control group underwent the same examinations. Nasal minimum cross-sectional area (cm(2)) and volume (cm(3)) were assessed (acoustic rhinometry). Airflow resistance (Pa s/cm(3)) (rhinomanometry), peak inspiratory flow (L/min) (peak nasal inspiratory flow), and number of identified odors (Scandinavian Odor Identification Test) were determined. The cleft side of unilateral cleft lip and palate patients had significantly lower values for all parameters compared with controls (p < .001). No difference was found between one-stage and two-stage procedures in values for the cleft side. However, the nasal area and volume of the noncleft side were significantly larger in patients who underwent one-stage as compared with two-stage procedures (p < .05). The nasal airway of unilateral cleft lip and palate patients demonstrates a wide range of impairments that can be quantified by objective measurements. However, the measurements used did not differentiate between patients operated on with the one-stage and two-stage procedures except for values of the noncleft side.

Effects of total laryngectomy on olfactory function, health-related quality of life, and communication: a 3-year follow-up study

BackgroundAs total laryngectomy results in loss of airflow through the nose, one of the adverse effects for a majority of patients is the reduced or complete loss of olfactory function. However, with the introduction of a new method, the Nasal Airflow-Inducing Maneuver (NAIM), an important technique is available for laryngectomized patients to regain the ability to smell. The purpose of the present study was to assess changes in olfaction, health-related quality of life (HRQL) and communication 3 years after NAIM rehabilitation.Methods18 patients (15 men and 3 women; mean age, 71 years) who had undergone laryngectomy and NAIM rehabilitation were followed longitudinally for 3 years. For comparison an age and gender matched control group with laryngeal cancer treated with radical radiotherapy was included. Olfactory function was assessed using the Questionnaire on Odor, Taste and Appetite and the Scandinavian Odor Identification Test. HRQL was assessed by: 1) the European Organization for Research and Treatment for cancer quality of life questionnaires; and 2) the Hospital Anxiety and Depression Scale. Communication was assessed by the Swedish Self-Evaluation of Communication Experiences after Laryngeal Cancer. Descriptive statistics with 95% confidence interval were calculated according to standard procedure. Changes over time as well as tests between pairs of study patients and control patients were analyzed with the Fisher nonparametric permutation test for matched pairs.ResultsThirty-six months after rehabilitation 14 of 18 laryngectomized patients (78%) were smellers. There were, with one exception (sleep disturbances), no clinically or statistically significant differences between the study and the control group considering HRQL and mental distress. However, statistical differences (p < 0.001) were found between the study and the control group concerning changes in communication.ConclusionOlfactory training with NAIM should be integrated into the multidisciplinary rehabilitation program after total laryngectomy. Our study shows that patients who were successfully rehabilitated concerning olfaction and communication had an overall good HRQL and no mental distress. Moreover, the EORTC questionnaires should be complemented with more specific questionnaires when evaluating olfaction and communication in laryngectomized patients.

Familiarity, Cued and Free Odor Identification and Their Association with Cognitive Functioning in Middle Aged and Older Adults

ABSTRACT The aim of the present study was to examine the association between familiarity of odors, cued and free odor identification performance and cognitive function in elderly adults. It was further investigated how age affects performance on the various odor tasks. A third aim was to investigate the role of familiarity in explaining performance on the free identification task. One hundred and thirty-six participants (aged 45–79 years) with normal olfactory sensitivity were assessed with the Scandinavian Odor Identification Test (SOIT) and standardized tests of cognitive function. Familiarity did not correlate with any measure of cognitive function, while verbal identification performance was associated with several cognitive measures, although correlations were modest. In this sample, free odor identification was affected by increasing age to a marginally larger extent than cued identification performance and familiarity ratings. The results suggest that the different olfactory tasks involve different levels of cognitive processing.

Effectiveness of Olfactory Rehabilitation With the Nasal Airflow-Inducing Maneuver After Total Laryngectomy

To assess the long-term results of the nasal airflow-inducing maneuver in olfaction rehabilitation in patients who had undergone laryngectomy. Prospective interventional study. University hospital. Twenty-four patients who had undergone laryngectomy (21 men and 3 women; mean age, 68 years) who received olfactory rehabilitation with the nasal airflow-inducing maneuver were reevaluated 6 and 12 months after primary treatment. Olfactory function was tested by means of a semistructured interview; the Questionnaire on Olfaction, Taste and Appetite; and the Scandinavian Odor-Identification Test. Quality of life was measured with the European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-H&N35 questionnaires. Patients were categorized as smellers or nonsmellers based on results of the Scandinavian Odor-Identification Test. Before treatment, 10 of 24 patients (42%) were smellers and 14 (58%) were nonsmellers. At 6-month follow-up, 20 of 23 patients (87%) were smellers, whereas after 12 months, 21 of 24 patients (88%) were smellers. Long-term olfaction rehabilitation was achieved in 11 of 14 patients (79%) with anosmia, and 15 of all 24 patients (63%) could be classified as having normal olfactory capacity at the end of the study. The nasal airflow-inducing maneuver is a patient-friendly, inexpensive, and effective method for restoring the sense of smell in patients after laryngectomy, and the results persist in the long term.

Screening and Rehabilitation of Olfaction After Total Laryngectomy in Swedish Patients

To examine the olfactory function in patients with laryngectomy and to assess the results of the Nasal Airflow-Inducing Maneuver (NAIM) odor-rehabilitation technique. A prospective intervention study. University hospital. Twenty-four patients, 21 men and 3 women, mean age 68 years, who underwent laryngectomy at least 5 months prior to intervention. Speech therapists trained patients in the NAIM technique: simultaneous lowering of the jaw, floor of the mouth, tongue, base of the tongue, and soft palate while the lips are closed. Three interventions were given within 6 weeks. Olfactory testing with semistructured interview, the Questionnaire on Olfaction, Taste, and Appetite (QOTA), and the Scandinavian Odor-Identification Test (SOIT). Quality of life was measured with European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-H&N35 questionnaires. The patients were categorized as smellers or nonsmellers based on the SOIT results. Before the treatment, 10 patients (42%) were smellers (ie, 6 had normosmia and 4 hyposmia), while 14 patients (58%) were nonsmellers (ie, all had anosmia). Thus, 18 patients had impaired olfaction. Using the NAIM technique, 13 (72%) of 18 patients with impaired olfaction showed improvement. Of the 14 nonsmellers, 7 converted to smellers after only 1 intervention session, giving us a success rate of 50% in anosmic patients after 1 session. Olfactory impairment is common in patients who underwent laryngectomy. The NAIM method is easy to learn and rapidly improves smell and taste. A single intervention session is sometimes sufficient, but many patients benefit from repeated training. The SOIT test is an effective and simple test for the assessment of olfaction acuity after laryngectomy.

Intakes of cold cuts in the elderly are predicted by olfaction and mood, but not by flavor type or intensity of the products

Means to boost food intake of the elderly ( n = 60, age range 61–86 years) varying in olfactory and mood status were studied during home-use of cold cuts. Enhancement group ( n = 28) received regular smoked ham and smoked ham flavored with extra strong smoke aroma or with pepper mix, and Variety group ( n = 32) received four different cold cuts: smoked ham, cooked ham, pepper ham and bologna. Both groups participated in two successive home-use periods, each over 6 days. Before and after home-use, the cold cuts were rated for odor and flavor intensity and liking, and in home-use only for liking. Cold cuts, 600 g per period, were to be consumed ad libitum, and the returned left-overs were weighed. Scandinavian Odor Identification Test and Profile of Mood States (bi-polar) were used in dividing subjects into normosmics and hyposmics (SOIT, cut-off score: 11) and into mood groups (POMS, depressed-elated, cut-off score: median). Enhancement group liked both the regular and the ham enhanced with pepper mix similarly, while added smoke aroma decreased liking. Regardless of the olfactory capabilities, the subjects > 74 years of age were less responsive to the flavor changes in their ratings than those aged 61–74 years. Poor olfactory status increased the intakes regardless of the flavor level or type of cold cuts. Path analysis suggested that in the Enhancement group, poor health, depressed mood and high age predicted a poor olfactory performance which, along with ratings of liking, increased the consumed amounts of cold cuts.

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.