'Sniffin' Sticks' is a new test of nasal chemosensory performance based on pen-like odor dispensing devices. It comprises three tests of olfactory function, namely tests for odor threshold (n-butanol, testing by means of a single staircase), odor discrimination (16 pairs of odorants, triple forced choice) and odor identification (16 common odorants, multiple forced choice from four verbal items per test odorant). After extensive preliminary investigations the tests were applied to a group of 104 healthy volunteers (52 female, 52 male, mean age 49.5 years, range 18-84 years) in order to establish test-retest reliability and to compare them with an established measure of olfactory performance (the Connecticut Chemosensory Clinical Research Center Test, CCCRC). Performance decreased with increasing age of the subjects (P < 0.001). Coefficients of correlation between sessions 1 and 2 were 0.61 for thresholds, 0.54 for discrimination and 0.73 for identification. Butanol thresholds as obtained with the CCCRC increased as a function of age; this relation to the subjects' age was not found for the CCCRC odor identification task. The test-retest reliability for CCCRC thresholds was 0.36, for odor identification it was 0.60. It is concluded that 'Sniffin' Sticks' may be suited for the routine clinical assessment of olfactory performance.

"Sniffin' Sticks" is a test of nasal chemosensory function that is based on pen-like odor dispensing devices, introduced some 10 years ago by Kobal and co-workers. It consists of tests for odor threshold, discrimination, and identification. Previous work established its test-retest reliability and validity. Results of the test are presented as "TDI score", the sum of results obtained for threshold, discrimination, and identification measures. While normative data have been established they are based on a relatively small number of subjects, especially with regard to subjects older than 55 years where data from only 30 healthy subjects have been used. The present study aimed to remedy this situation. Now data are available from 3,282 subjects as compared to data from 738 subjects published previously. Disregarding sex-related differences, the TDI score at the tenth percentile was 24.9 in subjects younger than 15 years, 30.3 for ages from 16 to 35 years, 27.3 for ages from 36 to 55 years, and 19.6 for subjects older than 55 years. Because the tenth percentile has been defined to separate hyposmia from normosmia, these data can be used as a guide to estimate individual olfactory ability in relation to subject's age. Absolute hyposmia was defined as the tenth percentile score of 16-35 year old subjects. Other than previous reports the present norms are also sex-differentiated with women outperforming men in the three olfactory tests. Further, the present data suggest specific changes of individual olfactory functions in relation to age, with odor thresholds declining most dramatically compared to odor discrimination and odor identification.

"Sniffin' Sticks" is a test of nasal chemosensory performance that is based on penlike odor-dispensing devices. It is comprised of three tests of olfactory function: tests for odor threshold, discrimination and identification. Previous work has already established its test-retest reliability and validity in comparison to established measures of olfactory sensitivity. The results of this test are presented as a composite TDI score--i.e., the sum of results obtained for threshold, discrimination and identification measures. The present multicenter investigation aimed at providing normative values in relation to different age groups. To this end, 966 patients were investigated in 11 centers. An additional study tried to establish values for the identification of anosmic patients, with 70 anosmics investigated in five specialized centers where the presence of anosmia was confirmed by means of olfactory evoked potentials. For healthy subjects, the TDI score at the 10th percentile was 24.5 in subjects younger than 15 years, 30.3 for ages from 16 to 35 years, 28.8 for ages from 36 to 55 years and 27.5 for subjects older than 55 years. While these data can be used to estimate individual olfactory abilities in relation to a subject's age, hyposmia was defined as the 10th percentile score of 16- to 35-year-old subjects. Our latter study revealed that none of 70 anosmics reached a TDI score higher than 15. This score of 15 is regarded as the cut-off value for functional anosmia. These results provide the basis for the routine clinical evaluation of patients with olfactory disorders using "Sniffin' Sticks."

The study aimed to create a screening test on the basis of the odor identification test as used in the "Sniffin' Sticks" olfactory test kit. It should appeal to the practitioner in terms of 1) time required for testing, 2) reliability, 3) separation of "normal" from "abnormal," and 4) the fact that it allows lateralized screening. Experiments should provide a normative database (number of subjects > 1,000), establish test-retest reliability (n > 100), and compare results from patients with olfactory loss (n > 200). The correlation between results on 2 repetitive tests was .78. The test differentiated anosmics, hyposmics, and normosmics (p < .001). None of the 112 anosmics reached a score higher than 8; the 90th percentile was at a score of 6. When only 6 odors were used for calculating scores, for anosmics the 95th percentile was at a score of 4. These data provide a basis for the screening of patients by means of "Sniffin' Sticks."

When a food is eaten to satiety, its reward value decreases. This decrease is usually greater for the food eaten to satiety than for other foods, an effect termed sensory-specific satiety. In an fMRI investigation it was shown that for a region of the orbitofrontal cortex the activation produced by the odour of the food eaten to satiety decreased, whereas there was no similar decrease for the odour of a food not eaten in the meal. This effect was shown both by a voxel-wise SPM contrast (p <0.05 corrected) and an ANOVA performed on the mean percentage change in BOLD signal in the identified clusters of voxels (p <0.006). These results show that activation of a region of the human orbitofrontal cortex is related to olfactory sensory-specific satiety.