Odor Identification Scores Research Articles

Neurofunctional dopaminergic impairment in elderly after lifetime exposure to manganese

BackgroundManganese (Mn) is an essential element that can become neurotoxic through various exposure windows over the lifespan. While there is clear evidence of Mn neurotoxicity in pediatric and adult occupational populations, little is known about effects in the elderly who may exhibit enhanced susceptibilities due to compromised physiology compared to younger adults. In the province of Brescia, Italy, the Valcamonica area has been the site of three ferroalloy plants operating from 1902 to 2001. Metal emissions of Mn and to a lesser extent lead (Pb) have impacted the surrounding environment, where a high prevalence of Parkinsonism was previously observed. This study aimed to assess neurocognitive and motor functions in healthy elderly subjects residing for most of their lifetime in Valcamonica or in a reference area unimpacted by ferroalloy plant activity. MethodsSubjects were enrolled for extensive neurobehavioral assessment of motor, cognitive and sensory functions. Exposure was assessed with 24h personal air sampling for PM10 airborne particles, surface soil and tap water measurement at individual households, Mn levels in blood and urine and Pb in blood. Dose–response relationships between exposure indicators and biomarkers and health outcomes were analyzed with generalized (linear and logistic) additive models (GAM). ResultsA total of 255 subjects (55% women) were examined; most (52.9%) were within the 65–70 years age class. Average airborne Mn was 26.41ng/m3 (median 18.42) in Valcamonica and 20.96ng/m3 (median 17.62) in the reference area. Average Mn in surface soil was 1026ppm (median 923) in Valcamonica and 421ppm (median 410) in the reference area. Manganese in drinking water was below the LDL of 1μg/L. The GAM analysis showed significant association between airborne Mn (p=0.0237) and the motor coordination tests of the Luria Nebraska Neuropsychological Battery. The calculation of the Benchmark Dose using this dose–response relationship yielded a lower level confidence interval of 22.7ng/m3 (median 26.4). For the odor identification score of the Sniffin Stick test, an association was observed with soil Mn (p=0.0006) and with a significant interaction with blood Pb (p=0.0856). Significant dose–responses resulted also for the Raven's Colored Progressive Matrices with the distance from exposure point source (p=0.0025) and Mn in soil (p=0.09), and for the Trail Making test, with urinary Mn (p=0.0074). Serum prolactin (PRL) levels were associated with air (p=0.061) and urinary (p=0.003) Mn, and with blood Pb (p=0.0303). In most of these associations age played a significant role as an effect modifier. ConclusionLifelong exposure to Mn was significantly associated with changes in odor discrimination, motor coordination, cognitive abilities and serum PRL levels. These effects are consistent with the hypothesis of a specific mechanism of toxicity of Mn on the dopaminergic system. Lead co-exposure, even at very low levels, can further enhance Mn toxicity.

Olfactory Dysfunction in Type 2 Diabetes Mellitus

We evaluated olfactory dysfunction in 154 adults (74 men, mean age 60.9±11.9 years), of whom 119 had type 2 diabetes mellitus (T2DM). Olfactory function was assessed with "Sniffin' Sticks." A total Threshold-Discrimination-Identification (TDI) score was calculated. Type 2 diabetes mellitus, hypertension, and hyperlipidemia were associated with lower olfactory scores (all TDI scores<0.001). Age was negatively associated with odor threshold, odor identification, and TDI score (P=.009, <.001, and <.001, respectively). After adjusting for age, gender, body mass index, smoking, alcohol, diabetes, hypertension, hyperlipidemia, and cardiovascular disease, only T2DM and hypertension were associated with TDI score (R square=0.281). Diabetic complications were associated with olfactory dysfunction (P=.006): TDI scores were lower in the presence of diabetic peripheral neuropathy (P=.017) and retinopathy (P=.047). In conclusion, T2DM and hypertension are independently associated with olfactory dysfunction while diabetic peripheral neuropathy and retinopathy are significantly associated with lower olfactory scores. The clinical relevance of these findings needs to be further examined.

Preventing Olfactory Deterioration: Olfactory Training May Be of Help in Older People

The olfactory system changes with age.1, 2 It has been reported that 50% of people aged 65 and older and more than 80% of people aged 80 and older have olfactory deficits.1, 3 Because odor identification1, 2 and sensitivity to odors2 decrease with age, older people are more likely to be harmed by fire or poisoned by rotten food.4, 5 Previous studies have proven the usefulness of olfactory training in treating olfactory deficits with varying etiologies.6, 7 The aim of this prospective study was to examine the effect of olfactory training in older people over a period of 3 months. All aspects of the study were performed in accordance with the Declaration of Helsinki. The ethics board of the Faculty of Medicine of the Technical University of Dresden approved the study (protocol EK 4002009). Written informed consent was obtained from all participants. Ninety-one participants (64 female, 27 male; mean age 81 ± 8.6, range 55–96) with a Mini-Mental State Examination score greater than 25 points were included in the study, 43 of whom (46.7%) performed the olfactory training. They were instructed to smell four common odors two times daily (in the morning and evening) for 30 seconds each. The odors were chosen according to previous studies:6, 7 citronellal (lemon), cineol (eucalyptus), phenyl-ethyl-alcohol (PEA; rose), and eugenol (cloves). Forty-eight (52.2%) participants were in the control group. The two groups did not differ regarding mean age (training group, 80.1 ± 7.8; control group, 81.6 ± 9.3; t = 0.81, P = .42) or sex (χ2=1.22, P = .14). The olfactory function of all participants was assessed twice at an interval of 3 months, during which the training group performed the olfactory training, using the 16-item odor identification test and the PEA threshold test from the Sniffin' Sticks battery.8 The control group did not differ from the training group in terms of olfactory function (mean olfactory threshold scores: control 3.71 ± 2.60, training group 4.20 ± 3.32; t = 0.70, P = .48; mean odor identification score: control 8.0 ± 2.8, training group 8.5 ± 3.9, t = 0.68, P = .50). A trend toward significance was observed between the two groups in odor threshold score at the second testing after 3 months (t = 1.69, P = .09). Although the olfactory function of the training group increased slightly, no significant change was seen for the odor threshold (t = 1.44, P = .16) or identification score (t = 0.41, P = .68). Olfactory function in the control group decreased slightly but not significantly. Fifty-two percent of the training group reported having followed the olfactory training protocol as instructed. This subgroup did not differ from the control group before the training in olfactory function (odor threshold score: t = 1.51, P = 0.14; odor identification score: t = 1.79, P = 0.083). After olfactory training, these two groups differed significantly in odor threshold performance (t = 2.32, P = .02) and odor identification scores (t = 2.19, P = .03) (Figure 1). No significant change was observed within the training group. Age and sex did not affect any of the comparisons mentioned above. The effect of olfactory training was observed over a 3-month period in older people. No significant increase in olfactory function was observed in the training group. Nonetheless, the olfactory training group had significantly higher olfactory test scores after the training than the control group. Olfactory training has been shown to improve olfactory function in individuals with hyposmia.6, 7 A benefit of olfactory training for older people has been suggested,2 but no study has previously addressed this topic. There are several possible reasons for the lack of olfactory improvement in the current study. With increasing age, the regenerative ability of the olfactory mucosa decreases, the number of mature olfactory receptor neurons decrease,9, 10 and cell turnover in the olfactory epithelium is slower.9 Taking all this into account, the olfactory system of older people does not seem to be as plastic as that of younger people, so a longer training interval might improve the benefit of olfactory training in older people. Although no significant improvement in olfactory function was observed, olfactory training seems to prevent olfactory deterioration that occurs with age. Conflict of Interest: None of the authors has any conflict of interest to disclose. This research was SPP 1392: DFG HU 441/10–1. Author Contributions: Concept and design: Lehmann, Prange, Hummel. Performance of experiments: Lehmann, Prange. Data analysis: Schriever, Hummel. Writing the paper: Schriever, Hummel. Critical discussion: Schriever, Hummel, Prange, Lehmann. Sponsor's Role: None.

The effect of obstructive sleep apnea on olfactory functions

The aim of this study was to investigate the effect of obstructive sleep apnea (OSA) on the parameters of olfactory functions (odor threshold, odor discrimination, and odor identification tests) for orthonasal olfaction, retronasal olfactory testing, and olfactory bulb (OB) volumes. Prospective clinical study. This study was carried out in 78 volunteers between the ages of 20 and 60 years. The mean age of the patients was 46 ± 10.1 years. Patients were divided into three groups according to polysomnography results: 1) a control group, 2) a mild to moderate OSA group, and 3) a severe OSA group. Clinical features of the participants were evaluated with the Epworth Sleepiness Scale. Orthonasal and retronasal olfactory testing were performed with Sniffin' Sticks olfactory testing and retronasal olfactory testing, respectively. Olfactory bulb volumes were measured by planimetric manual contouring on magnetic resonance imaging (MRI). The current investigation produced four major findings: 1) The apnea-hypopnea index had a significant and strong negative correlation with odor threshold scores and odor discrimination scores; 2) The apnea-hypopnea index was significantly negatively correlated with odor identification score and both right and left OB volumes; 3) retronasal olfactory scores were not significantly affected by OSA; and 4) continuous O2 saturation had a significant positive correlation on orthonasal olfactory functions, particularly the odor threshold and discrimination scores. This study demonstrated that OSA had significant negative effects on all orthonasal olfactory tasks, especially on threshold and discrimination. MRI also revealed volumetric shrinkage of OB volumes.

Does bariatric surgery change olfactory perception? Results of the early postoperative course

Changes of food preference toward foods with low caloric density have been demonstrated after bariatric surgery and may contribute to sustained body weight loss. It has been hypothesized that olfactory perception as an integral part of food selection might be altered after bariatric surgery. Sniffin' Sticks® were used to investigate the olfactory perception of morbidly obese patients undergoing either Roux-en-Y gastric bypass (RYGB, n = 15) or sleeve gastrectomy (SG, n = 15) before 1, 6, 12, and 24weeks after surgery. Obese patients without surgical intervention served as controls (CG, n = 12). Results are presented using the testing odor threshold, discrimination, and identification score (TDI; higher scores indicate better olfactory perception). Body weight loss was recorded. Initial BMI of the SG group (56.04 ± 7.096kgm(-2)) was higher compared to the BMI of the RYGB (48.71 ± 6.49kgm(-2)) and CG (50.35 ± 6.78kgm(-2)); p = 0.011. Body weight loss among the surgical groups was not different (p = 0.011) while controls did not lose weight. Mean baseline TDI scores were significantly lower in the SG group 27.1 ± 3.9 vs. 32.6 ± 3.6 (RYGB) and 32.1 ± 5.3 (CG), respectively, whereas there were after 24weeks no changes in RYGB and CG patients; the TDI score in the SG group increased significantly to 31.1 ± 3.5 (p < 0.01). Our data suggest that a substantial body weight loss per se does not affect olfactory perception. However, our results point towards improved olfactory perception after sleeve gastrectomy but not Roux-en-Y gastric bypass.

Olfactory Performance Is Predicted by Individual Sex-Atypicality, but Not Sexual Orientation

Many previous studies have reported robust sex differences in olfactory perception. However, both men and women can be expected to vary in the degree to which they exhibit olfactory performance considered typical of their own or the opposite sex. Sex-atypicality is often described in terms of childhood gender nonconformity, which, however, is not a perfect correlate of non-heterosexual orientation. Here we explored intrasexual variability in psychophysical olfactory performance in a sample of 156 individuals (83 non-heterosexual) and found the lowest odor identification scores in heterosexual men. However, when childhood gender nonconformity was entered in the model along with sexual orientation, better odor identification scores were exhibited by gender-nonconforming men, and greater olfactory sensitivity by gender-conforming women, irrespective of their sexual orientation. Thus, sex-atypicality, but not sexual orientation predicts olfactory performance, and we propose that this might not be limited to olfaction, but represent a more general phenomenon.

Greater overall olfactory performance, explicit wanting for high fat foods and lipid intake during the mid-luteal phase of the menstrual cycle

Increases in energy, lipid and carbohydrate intakes during the luteal phase have been previously observed. However, it is not known whether this is due to phase-dependent variations in the reward value of certain foods. Moreover, increases in olfactory sensitivity have been proposed and may be involved in these changes in food reward. Therefore, we examined olfactory performance and the reward value of foods varying in fat content and taste. Seventeen women (Body mass index: 22.3±1.6kg/m2; Body fat-DXA: 28.5±6.8%) were recruited to participate in 3 identical sessions, performed during distinct phases of the menstrual cycle – early follicular/menstruation, late follicular/ovulation and mid-luteal – verified by plasma sex-steroid hormones and oral temperature. Food preference, implicit wanting, and explicit wanting and liking for visual food cues, varying in fat content and taste, were measured with a validated experimental platform involving a forced choice computer task. Odour threshold, odour discrimination, odour identification and total odour scores were measured using odourized pens. Ad libitum energy and macronutrient intake was measured with a validated food menu. Results showed greater total odour scores (p<0.05), explicit wanting for high fat foods (p<0.05) and lipid intake (p<0.05) during the mid-luteal phase. Inter-correlations between these variables were non-significant. These findings support previous observations of increased lipid intake during the luteal phase and provide evidence for phase-dependent variation in overall olfactory performance and explicit wanting for high fat foods.

The applicability of the “Sniffin’ Sticks” olfactory test in a Turkish population

BackgroundOlfactory assessment is often neglected in clinical practice, although olfactory loss can assist in diagnosis and may lead to significant morbidity. “Sniffin’ Sticks” is a modern test of nasal chemosensory performance that was developed in Germany and validated in many countries. Our aim was to validate the applicability of “Sniffin’ Sticks” in a Turkish population.Material/MethodsThe study included 123 healthy volunteers with a reported normal sense of smell and 51 patients complaining of a reduction in their olfactory function presenting either at rhinology or neurology clinics. The mean age of the subjects tested was 30.2±12.5 years in 126 males and 48 females. The participants were divided into 2 groups according to subjective olfactory function – healthy or abnormal. Each subject’s olfactory function was assessed using the “Sniffin’ Sticks” test.ResultsWe found significant differences in “Sniffin’ Sticks” test results between the abnormal and healthy groups. In healthy subjects, the 10th percentiles of odor threshold score, odor discrimination score, odor identification score, and TDI score were 7.25, 12, 11, and 32, respectively. Considering the 2 groups together, apple and turpentine were the least well-recognized odors from the 16 odors presented.ConclusionsOur study provides an update of normative values for routine clinical use of “Sniffin’ Sticks” in a Turkish population. Also, the present study validates that “Sniffin’ Sticks” olfactory test was applicable for clinical usage in a Turkish population.

Olfaction in athletes with concussion

Moderate to severe traumatic brain injuries (TBIs) commonly lead to olfactory dysfunction; it is, however, unclear whether and to what degree mild TBI such as concussions, which are common sports injuries, affect olfactory function. We therefore aimed to evaluate smell function in athletes who sustained one or more sport concussions in a cross-sectional design. Twenty-two University-level football players with one or multiple concussions and 13 control athletes without a history of concussion participated. We measured olfactory function by using the Sniffin' Sticks test to assess subjects' ability to discriminate and identify odors as well as their detection thresholds. In addition, we assessed odor intensity and pleasantness. We used number of concussions and time since the last concussion as independent variables and measure of olfactory function as dependent variables. Although we did not observe any significant effect of the number of concussions, athletes with a longer delay from time of concussion scored significantly weaker than more recently concussed subjects on the odor identification test and on an aggregate olfactory score. Accordingly, we observed a significant negative linear correlation between the odor identification score and the time elapsed since the last concussion. These findings suggest a possible degenerative effect of concussions on olfactory function.

Application of odor identification test in Parkinson's disease in China: A matched case-control study

As one of the most common non-motor symptoms in Parkinson's disease (PD), hyposmia is of great importance in establishing the early diagnosis of PD. To date, there are still no studies on the application of the 16-item odor identification test from Sniffin' Sticks (SS-16) in Chinese patients with PD. The aim of this study was to investigate the validity of SS-16 in Chinese PD patients (n=110) compared with age and gender matched controls (n=110), and to explore the associated factors with olfactory function in PD patients. The 16 odors in the original odor identification test were retained but some alternative descriptions were developed before applications. Mean identification scores in patients were significantly lower than in controls (7.3±2.8 VS. 11.6±2.0 P<0.01), with 66.4% of patients had an impairment of odor identification as evaluated by 95% confidential interval of the identification score of the control group. Receiver operating characteristic curves revealed 86% sensitivity and 81% specificity in separating PD and healthy controls with a cut-off value of 9.5. Multiple linear regression analysis revealed that autonomic dysfunction was a significant influential factor of odor identification scores in patients with PD. In conclusion, SS-16 provides a valid instrument for olfactory assessment in Chinese PD patients, and hyposmia may correlate with autonomic dysfunction in patients with PD.

Topical corticosteroids applied with a squirt system are more effective than a nasal spray for steroid‐dependent olfactory impairment

Oral corticosteroids may restore conductive olfactory dysfunction that has been defined as steroid-dependent olfactory loss, but the effect may be temporary. This study was designed to evaluate whether applying topical corticosteroids with a squirt system was more effective than using a nasal spray to maintain olfactory improvement following oral corticosteroids. Prospective randomized trial enrolling 32 patients. Patients were enrolled if they had suffered from olfactory dysfunction for more than 3 months, and if their composite scores of odor threshold, discrimination, and identification scores in Sniffin' Sticks olfactory tests increased by more than six points after 1 week of oral corticosteroid treatment. A total of 32 patients were enrolled and randomized into two groups. All patients were treated with topical corticosteroids for 2 months using either the spray or squirt system, respectively. Both measured and self-rated olfactory functions after 1 and 2 months of topical corticosteroid treatment were better in the squirt group than in the spray group. However, 2 months of topical corticosteroid treatment with the squirt system only partially maintained olfactory improvement. The application of topical corticosteroids with a squirt system was more effective than with a spray in maintaining olfactory improvement with oral corticosteroid treatment. Nevertheless, it only partially maintained the improvement so that topical corticosteroid treatment using a squirt system needs to be combined with intervals of short-term oral corticosteroids to treat steroid-dependent olfactory loss while avoiding the side effects of long-term oral corticosteroid use.

Validation study of the “Sniffin’ Sticks” olfactory test in a British population: a preliminary communication

The 'Sniffin' Sticks' olfactory test contains pen-like odour dispensing devices which are used to assess olfactory threshold, discrimination and identification. Odour identification is strongly dependent on familiarity with the odours and has an important cultural component which has limited the usefulness of other validated tests. The 'Sniffin' Sticks' test was developed in Germany and is validated in other countries but not in the UK. This study aims to validate the applicability of 'Sniffin' Sticks' in a local population. Prospective controlled study. Rhinology or olfactory disorder clinic. About 82 subjects, 33 healthy volunteers with a reported normal sense of smell, and 49 patients with an impaired sense of smell presenting either at a rhinology or an olfactory disorder clinic. Each subject's olfactory function was assessed using the 'Sniffin' Sticks' test with a maximum score of 48. Threshold, discrimination and identification scores along with the combined olfactory score. The mean age of the subjects tested was 46.7 years; 46 female and 36 male. In the patient group 36 were hyposmic and 13 anosmic. In the healthy volunteers group all subjects were normosmic. In the control group the mean combined olfactory score was 34.5 (±2.5). The mean combined score in the patients group was 20.8 (±7.4). Odour threshold scores were 3.7(±2.8) for patients (hyposmics and anomics) and 8.3(±1.8) for controls. In the identification test the controls mean score was 13.6 (±1.2) for while the patients' mean score was 8.6 (±3.5). In our sample of the local population the combined olfactory and odour identification scores for healthy volunteers and patients with olfactory disorders are comparable with the normative data published on large samples of European populations. However, modification of a few of the distracters is recommended for British patients based on our findings.

Radiofrequency Inferior Turbinate Reduction

The aim of this study was to assess the long-term effects of radiofrequency inferior turbinate reduction (RITR) on nasal function in patients affected by nasal obstruction secondary to turbinate hypertrophy, focusing attention on increased sense of smell and its persistence after a 2-year follow-up. Case series with planned data collection. ENT division, university hospital. A total of 40 consecutive patients undergoing RITR for allergic or nonallergic chronic rhinitis with inferior turbinate hypertrophy were included. We planned a series of tests, including the "Sniffin' Sticks" test battery, anterior rhinomanometry, and the nasal Obstruction Symptom Evaluation (NOSE) scale, on the day of the procedure and at the 2-month and 2-year follow-up visits. Of the 40 patients, 35 completed all the objective and subjective examinations on the day of the procedure and at the 2-month and 2-year follow-up visits. The authors found a significant decrease in nasal resistances from a mean of 1.13 Pa/cm(3)s(-1) preoperatively to a mean of 0.29 Pa/cm(3)s(-1) 2 years postoperatively and improvement in odor threshold, discrimination, and identification scores 2 years postoperatively. The NOSE score diminished significantly 2 years after surgery from a mean of 23.14 to a mean of 4.14 (all P < .01 with the t test for repeated measures). This long-term evaluation showed that radiofrequency treatment for allergic or nonallergic inferior turbinate hypertrophy appeared to provide improvement in olfaction, decrease nasal resistances, and have subjective benefits, maintained 2 years after the procedure.

Validation of Sniffin’ Sticks Olfactory Test and Olfactory Disorder Questionnaire in a UK Population

Objective: Validate the applicability of Sniffin’ Sticks in a UK population. These pen-like odor dispensing devices are used to assess threshold, discrimination, and identification. Odor identification is strongly dependent on familiarity with the odors and has an important cultural component, which has limited the usefulness of other validated tests. Method: A prospective study of 63 subjects, 24 healthy volunteers with a reported normal sense of smell, and 39 patients with an impaired sense of smell presenting either at a rhinology or an olfactory disorder clinic. Each subject’s olfactory function was assessed using the Sniffin’ Stick test. Results: The mean age of the subjects tested was 46.7 years; 40 female and 23 male. In the patient group, 30 were hyposmic and 9 anosmic. In the healthy volunteers group, all subjects were normosmic. The mean TDI score for patients and healthy volunteers was 21.06 (range, 8-30.5) and 33.73 (range, 29.25-37.75) respectively. Mean identification score in the 2 groups was 8.84 (range, 1-15) for patients (range) and 13.69 (range, 11-16) for healthy volunteers. Conclusion: In our sample of the UK population the TDI and odor identification scores for healthy volunteers and patients with olfactory disorders are comparable with the normative data published on large samples of European populations. Discussion of commonly mistaken odors in the odor identification test is undertaken.

Gustatory and olfactory dysfunction in older adults: a national probability study

Olfactory and gustatory functions have not been well characterized in older adults in the US. Consequently, their relationships to sociodemographic characteristics, as well as physical and mental health, were studied in a large national probability sample using brief validated tests of chemosensory function. A five-odour identification test and taste-impregnated strips of filter paper (sweet, sour, bitter, and salty) assessed the ability to identify chemosensory stimuli. Severe gustatory dysfunction was more prevalent than severe olfactory dysfunction. Age, education and sex were independently associated with performance on both the olfactory and gustatory identification tasks. Higher scores were associated with female sex, higher level of education, and lower age. Odour identification scores exhibited a positive, albeit weak, correlation with BMI, and food-related odours were better identified than non-food odours. In addition, odour identification performance was also negatively associated with depressive symptoms. These data demonstrate a high prevalence of severe gustatory and, to a somewhat lesser extent, olfactory dysfunction in a population-based sample and demonstrate that even brief tests are capable of detecting correlations between both chemical senses and relevant health measures outside a clinical setting.

Olfactory dysfunction is associated with neuropsychiatric manifestations in Parkinson's disease

Hyposmia, psychiatric disorders, and cognitive problems are common nonmotor manifestations in Parkinson's disease, but how they are related remains unclear. We investigated the relationship between olfactory dysfunction and neuropsychiatric manifestations and performed a cross-sectional study of 248 patients at two movement disorders clinics at academic medical centers. Psychiatric measures were the Geriatric Depression Scale-15, Inventory of Depressive Symptomatology, State Anxiety Inventory, Apathy Scale, and Parkinson's Psychosis Rating Scale. Cognitive measures were the Mini-Mental State Examination, Hopkins Verbal Learning Test-Revised, Digit Span, Tower of London-Drexel, and the Stroop Color Word Test. Olfaction was tested with the University of Pennsylvania Smell Identification Test. There was no significant association between olfaction and mood measures, but psychotic symptoms were more common in patients with olfaction scores below the median (30% vs. 12%; P < 0.001). Worse olfaction was associated with poorer memory (Hopkins Verbal Learning Test-Revised delayed recall items: mean [standard deviation], 6.2 [3.2] vs. 8.4 [2.8]; P < 0.001) and executive performance (Tower of London total moves, 52 [38] vs. 34 [21]; P < 0.001). Odor-identification score was a significant predictor of abnormal performance on these cognitive tests after adjustment for age, sex, and disease characteristics in logistic regression models. The relationship between hyposmia, psychosis, and specific cognitive impairments may reflect the anatomic distribution of Lewy pathology and suggests that olfactory dysfunction could be a biomarker of additional extranigral disease. Future prospective studies are warranted to assess whether hyposmia, a very early feature of Parkinson's disease, might be used to predict the appearance of other common nonmotor symptoms.

Differences in odor identification among clinical subtypes of Parkinson’s disease

Olfactory dysfunction is a non-motor symptom in idiopathic Parkinson's disease (PD). We investigated whether this dysfunction differs among clinical subtypes of PD. Participants comprised of 90 patients with idiopathic PD and without dementia. Olfactory function was evaluated using the odor stick identification test for Japanese, which evaluated the detection of 12 odorants familiar to Japanese participants. Patients were divided into tremor-dominant type (TDT), akinetic-rigid type (ART), and mixed type (MXT) PD subgroups using part III of the Unified Parkinson's Disease Rating Scale. Fifty-five patients were classified as ART, 21 as MXT, and 14 as TDT. There were no differences in age, sex, or duration of illness among the subtypes. Subjective symptoms of impaired sense of smell were significantly higher (P<0.05) in the ART than in the TDT. Mean odor identification score was 4.3 in the ART, 5.2 in MXT, and 6.6 in TDT. It was significantly lower in the ART than in the TDT (P<0.01). Olfactory dysfunction differed among the clinical subtypes of PD. This suggests that olfactory function might relate to prognosis of patients with PD.

Lewy bodies and olfactory dysfunction in old age.

As part of a clinical-pathologic project, older people completed a standard odor identification test at study entry. During a mean of 3.5 years of observation, 201 people died and underwent brain autopsy and neuropathologic examination (6 with a history of Parkinson's disease were excluded). Lewy bodies were identified with antibodies to alpha-synuclein and classified as nigral, limbic, or neocortical based on their distribution in 6 brain regions. Plaques and tangles in 5 regions were summarized with a previously established composite measure, and neuron loss in the substantia nigra was rated on 6-point scale. Odor identification scores ranged from 0 to 12 correct (mean = 8.0, standard deviation = 2.6). On neuropathologic examination, 26 persons had Lewy bodies (13 neocortical, 9 limbic, and 4 nigral). In an analysis adjusted for age, sex, education, and time from olfactory testing to death, limbic (estimate = -2.47, standard error [SE] = 0.73, P < 0.001) and neocortical (estimate = -4.36, SE = 0.63, P < 0.001) Lewy body subgroups were associated with impaired olfaction. Results were comparable in analyses that controlled for dementia or parkinsonism during the study or postmortem measures of plaques and tangles or nigral cell loss. A final set of analyses suggested that impaired olfactory performance may aid detection of underlying Lewy body disease. The findings indicate that Lewy body disease impairs late life olfactory function even in otherwise asymptomatic individuals.

Idiopathic REM Sleep Behavior Disorder: Implications for the Pathogenesis of Lewy Body Diseases.

Objectives. Both results of the odor identification and cardiac 123I-metaiodobenzylguanidine accumulation have been investigated for their potential to enhance the detection of pathogenesis resembling that of Lewy body-related α-synucleinopathies in patients clinically diagnosed as having idiopathic REM sleep behavior disorder. Methods. We performed both the Odor Stick Identification Test for Japanese and 123I-metaiodobenzylguanidine scintigraphy in 30 patients with idiopathic REM sleep behavior disorder, 38 patients with Parkinson's disease, and 20 control subjects. Results. In idiopathic REM sleep behavior disorder, reduced odor identification score and an early or delayed heart to mediastinum ratio on 123I-metaiodobenzylguanidine were almost as severe as in Parkinson's disease patients. Delayed cardiac 123I-metaiodobenzylguanidine uptake was even more severe in the idiopathic REM sleep behavior disorder group than in the Parkinson's disease group. Conclusions. Reduced cardiac 123I-metaiodobenzylguanidine uptake, which is independent of parkinsonism, may be more closely associated with idiopathic REM sleep behavior disorder than olfactory impairment.

Smell and taste function in children with chronic kidney disease

Loss of appetite and poor growth are common in children with chronic kidney disease (CKD), and changes in smell and/or taste function may be responsible, but the hypothesis has not been proven. This aims of this prospective age- and gender-controlled study were to determine whether: (1) changes in smell and taste function occur in children with CKD; (2) smell or taste dysfunction are associated with estimated glomerular filtration rate (eGFR); (3) there is an association between smell or taste loss and body mass index (BMI). The study cohort consisted of 72 children of whom 20 were CKD stage 3-5 patients, 12 were CKD stage 2 patients, 20 were clinical controls (CC) and 20 were healthy children (HC). The CKD patients and clinical controls were recruited from Sydney Children's Hospital and The Children's Hospital, Westmead, and healthy controls were recruited from a local school. Scores for each group from taste and smell chemosensory function tests were compared, and their relationship with renal function and BMI investigated. The CKD stage 3-5 group had a significantly lower taste identification score (85.6%, P < 0.001) than the CC (94.8%) and HC (94.8%) groups, with almost one third of the children in the CKD stage 3-5 group exhibiting taste loss. Decreased taste function was associated with decreased eGFR (r = 0.43, P < 0.01), but no association between BMI and taste function was found (r = 0.001, P > 0.9). Odour identification scores were not different; however, there was a positive relationship with BMI (r = 0.427, P = 0.006). We conclude that a loss of taste can occur in children with CKD and that when it occurs, it worsens as eGFR declines and is found early in kidney disease.