Hedonic perception of odors in children aged 5-8 years is similar across 18 countries: Preliminary data.

OBJECTIVE: Olfactory preference emerges very early in life, and the sense of smell in children rapidly develops until the second decade of life. It is still unclear whether hedonic perception of odors is shared in children inhabiting different regions of the globe. METHODS: Five-hundred ten healthy children (N = 510; ngirls = 256; nboys = 254) aged from 5 to 8 years from 18 countries rated the pleasantness of 17 odors. RESULTS: The hedonic perception of odors in children aged between 5 and 8 years was rather consistent across 18 countries and mainly driven by the qualities of an odor and the overall ability of children to label odorants. CONCLUSION: Conclusions from this study, being a secondary analysis, are limited to the presented set of odors that were initially selected for the development of U-Sniff test and present null findings for the cross-cultural variability in hedonic perception of odors across 18 countries. These two major issues should be addressed in the future to either contradict or replicate the results presented herewith. This research lays fundament for posing further research questions about the developmental aspects of hedonic perception of odors and opens a new door for investigating cross-cultural differences in chemosensory perception of children.

"U-Sniff" - the international odor identification test for children: an extension of its normative database and study of global reliability.

BACKGROUND: To extend the previous study by Schriever and colleagues from 2018 providing normative data and re-investigating the reliability for U-Sniff test in children in additional countries. METHODOLOGY: A total of 388 children (196 boys, 192 girls) from eight countries (China, Germany, Iran, Netherlands, Norway, Oman, Paraguay, and Russia) participated in this study. The children were recruited from public local schools in those particular countries. The odor identification ability was evaluated using the U-Sniff test, a 12-item odor identification test developed for children. In addition, reliability was examined using test-retest design in the children for each country. RESULTS: The mean U-Sniff test score across all children was 10.3 +- 1.7 points. Normative data were established. A high test-retest reliability of the U-Sniff test was demonstrated across the eight participating countries. CONCLUSIONS: The U-Sniff test for children exhibits a high test-retest reliability on a global scale.

Separating normosmic and anosmic patients based on entropy evaluation of olfactory event-related potentials.

OBJECTIVE: Methods based on electroencephalography (EEG) are used to evaluate brain responses to odors which is challenging due to the relatively low signal-to-noise ratio. This is especially difficult in patients with olfactory loss. In the present study, we aim to establish a method to separate functionally anosmic and normosmic individuals by means of recordings of olfactory event-related potentials (OERP) using an automated tool. Therefore, Shannon entropy was adopted to examine the complexity of the averaged electrophysiological responses. METHODS: A total of 102 participants received 60 rose-like odorous stimuli at an inter-stimulus interval of 10 s. Olfactory-related brain activity was investigated within three time-windows of equal length; pre-, during-, and post-stimulus. RESULTS: Based on entropy analysis, patients were correctly diagnosed for anosmia with a 75% success rate. CONCLUSION: This novel approach can be expected to help clinicians to identify patients with anosmia or patients with early symptoms of neurodegenerative disorders. SIGNIFICANCE: There is no automated diagnostic tool for anosmic and normosmic patients using OERP. However, detectability of OERP in patients with functional anosmia has been reported to be in the range of 50%.

Updated Sniffin' Sticks normative data based on an extended sample of 9139 subjects.

PURPOSE: To provide up-to-date and detailed normative data based on a large-scale sample, increasing diagnostic validity by reference to narrow age groups as previous normative values were based upon smaller sample sizes-especially in the group of older subjects. METHOD: Data were obtained from 9139 healthy subjects (4928 females aged 5-96 years and 4211 males aged 5-91 years). The standard "Sniffin' Sticks" test was applied, comprising threshold (T), discrimination (D) and identification (I) subtests, and yielding a TDI sum score. RESULTS: Hyposmia was established at a TDI score of less than 30.75. Age-related changes were found in each domain, most pronounced for thresholds. Individuals aged 20-30 years performed best, whereas children below the age of 10 and adults above the age of 71 scored only half as well. Sex-related differences were in favor of women. CONCLUSIONS: Data provide guidance for assessing individual olfactory performance in relation to specific age groups. Significant gender and age effects were observed, with a most pronounced increase of olfactory test scores between age 5 through 20 years and a dramatic decrease at the age of 60 through 71 years.

Exposure to odours improves olfactory function in healthy children.

BACKGROUND: Short-term exposure to odours, also called "olfactory training" has been shown to improve olfactory function in healthy people but also in people with olfactory loss. Aim of this single center, prospective, controlled study was to investigate the change of olfactory function following twice-daily, short-term exposure to 4 odours over a period of approximately 12 weeks. MATERIAL AND METHODS: We compared odour identification abilities and odour thresholds between an olfactory training group (TR group) and a group that did not perform such training (noTR group). Participants exposed themselves twice daily to 4 odours ("rose", "eucalyptus", "lemon", "clove"). Olfactory testing was performed before and after the training period using the "Sniffin' Sticks" test kit (odour identification plus odour thresholds). RESULTS: At baseline the two groups were not significantly different in terms of age and measures of olfactory sensitivity. The TR group performed significantly better for odour thresholds for all 4 odours compared to the noTR group after 12 weeks of olfactory training. Also, with regard to odour identification the TR group outperformed the noTR group. No significant differences were found for diary-based intensity ratings. CONCLUSION: Repeated exposure to odours seems to improve general olfactory sensitivity in children.

Olfactory speed - Temporal odor processing of paired stimuli.

OBJECTIVES: Compared to other senses, temporal perception of odors seems fairly slow. In addition it has been shown in previous studies that even not consciously perceived odors could influence our behavior. Aim of the current study therefore was to study the interstimulus interval (ISI) length, which is necessary between two repetitive stimuli to be able to perceive them separately. The additional aim focused on observing central odor processing of not perceived odorous stimuli. MATERIALS AND METHODS: The study was divided into three parts. In each part healthy, normosmic volunteers were included. In part I and II stimulus pairs (CO2, H2S, orange and phenyl ethyl alcohol (PEA)) were presented to the subjects via a computer-controlled olfactometer with short ISI of 0.6-9s. The decision whether one or two stimuli were perceived was recorded. In addition the influence of odor valence, trigeminallity and concentrations was observed. In part III olfactory event-related potentials (OERPs) to perceived and not-perceived odors were recorded. RESULTS: The two stimuli of a stimulus pair were perceived separately more often with increasing ISI length. This increase was significant until an ISI between the stimuli of 4s. Odor intensity, pleasantness, trigeminallity and sex had no major influence on this. In addition we were able to observe that OERPs are less often detected in response to not perceived olfactory stimuli. However, the presence of OERP in response to not perceived stimuli in more than half of the cases indicated that even not perceived stimuli are centrally processed.

Changes of olfactory abilities in relation to age: odor identification in more than 1400 people aged 4 to 80 years.

The currently presented large dataset (n = 1,422) consists of results that have been assembled over the last 8 years at science fairs using the 16-item odor identification part of the "Sniffin' Sticks". In this context, the focus was on olfactory function in children; in addition before testing, we asked participants to rate their olfactory abilities and the patency of the nasal airways. We reinvestigated some simple questions, e.g., differences in olfactory odor identification abilities in relation to age, sex, self-ratings of olfactory function and nasal patency. Three major results evolved: first, consistent with previously published reports, we found that identification scores of the youngest and the oldest participants were lower than the scores obtained by people aged 20-60. Second, we observed an age-related increase in the olfactory abilities of children. Moreover, the self-assessed olfactory abilities were related to actual performance in the smell test, but only in adults, and self-assessed nasal patency was not related to the "Sniffin' Sticks" identification score.

Changes of olfactory processing in childhood and adolescence.

OBJECTIVES: Olfactory event-related potentials (OERPs) are widely used to study central odor processing. Only a few studies used this method in children and adolescents. Aim of the current study therefore was to measure OERP and the possible influences of age and sex on central odor processing in this age group. METHODS: A total of 81 children between 6 and 17 years of age were included in this study. OERP in response to a rose-like odor were measured from three recording positions (Fz, Cz, Pz) according to the 10-20 system. Stimuli were presented by means of a computer-controlled olfactometer. RESULTS: Age had a significant influence on the amplitudes of the late positivity with younger children showing larger amplitudes. Although age did not significantly affect the latencies of OERP, interactions of recording positions and latencies between younger and older children and between girls and boys were found. CONCLUSIONS: OERP can be used to study central odor processing in children older than 6 years of age. Central odor processing changes from childhood to adolescents possibly reflecting maturation of the brain.

[Diagnosis of olfactory disorders]. / Diagnostik bei Riechstörungen.

Alongside a structured case history, the measurement of olfactory function and diagnosis of olfactory dysfunction is of great clinical importance. Validated and established methods have been developed to this aim. The "Sniffin' Sticks" test battery is an easy-to-use tool for assessing olfactory function. Recording of olfactory event-related potentials is a more objective approach, which is particularly important in medicolegal cases. Imaging techniques such as MRI and CT provide additional information in the diagnosis of olfactory disorders. The latter techniques enable the anatomical structures of the skull and brain with the areas relevant to olfactory function to be evaluated.

Olfactory function following nasal surgery: a 1-year follow-up.

Olfactory dysfunction is a frequent symptom of nasal and sinunasal disease. Many of these patients undergo nasal sinus or nasal septum surgery. In this study, we evaluated the benefit of nasal surgery on olfactory function over a period of 12 months. Patients included in this study underwent either nasal sinus or nasal septum surgery. All patients were tested for olfactory function using the "Sniffin' sticks" 16 item odor identification test. In addition, patients were asked to rate their nasal patency as well as their olfactory function at each visit. 157 patients were tested 3.5 months after surgery and 52 patients were tested again 12 months after surgery. Olfactory function improved significantly 3.5 months after surgery in patients, who received nasal sinus surgery; no significant increase was found in patients treated with nasal septum surgery. At the 12-month follow-up, the increase in olfactory function over all patients just missed statistical significance. Individually, however, 19% of the patients exhibited improvement after 3.5 months and 17% after 12 months. These numbers increased in patients with rhinosinusitis with nasal polyps, who exhibited improvement of 30% after 3.5 months, and 32% after 12 months. Nasal sinus surgery produced an increase in measured olfactory function, but not nasal septum surgery. This increase appeared to be stable over the examined period of 12 months.

Treatment of smell loss with systemic methylprednisolone.

BACKGROUND AND AIM: Olfactory dysfunction is a common complaint in a large number of people. As the aetiologies of olfactory dysfunction vary greatly so do the treatment approaches. The aim of this retrospective study was to evaluate treatment with systemic corticosteroids, particularly focusing on its effectiveness on the different olfactory dysfunction aetiologies. Although a prospective randomized control trail is preferred for such an investigation, using the current approach, we were able to test a very large patient population. MATERIAL AND METHODS: A total of 425 patients with olfactory dysfunction were treated with systemic corticosteroids for 14 days. Olfactory performance was measured using the `Sniffin` Sticks` battery before and after the treatment. RESULTS: The treatment with systemic corticosteroids significantly increased the performance on the TDI score and on each of the three subtests; threshold, discrimination and identification. In 26.6% of the patients improvement of more than six points of the TDI score was observed. The treatment proved to be more effective in patients with sinunasal olfactory dysfunction, where this percentage increased to 36.7, compared to other aetiologies. In addition, the increase in olfactory function was negatively correlated with the TDI score before the treatment. CONCLUSION: This study confirms the effectiveness of systemic corticosteroids on olfactory dysfunction in a large patient population. Specifically, the results show that treatment is: (a) more effective in patients with sinunasal than in patients with idiopathic olfactory dysfunction, (b) most effective in patients with sinunasal disease with nasal polyps, and (c), at best, effective in half of the patients. The current study may provide help in counselling patients.