'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 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."

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We investigated chemosensory functions in patients with temporal lobe epilepsy (TLE) to discover whether olfactory and trigeminal stimuli applied either ipsilaterally or contralaterally to the epileptic focus are processed differently. Twenty-two patients were investigated, 12 of whom had epilepsy with a focus located in left temporal lobe (LTL). The remaining 10 patients had a right temporal lobe (RTL) focus. Input from the trigeminal system was examined by use of CO2; input from the olfactory system was evaluated with vanillin and hydrogen sulfide as stimuli. Chemosensory function was assessed by evaluation of chemosensory event-related potentials (CSERP) and the patients' verbal reports in an odor identification test. In both groups of patients, prolonged CSERP latencies were noted after stimulation of the left nostril with CO2 as compared with stimulation of the right nostril. In contrast, a different pattern emerged for olfactory stimuli. After right-sided olfactory stimulation, latencies were prolonged in patients with right-sided epileptical foci. Similarly, when the left nostril was stimulated in patients with a left-sided focus, CSERP latencies were prolonged. Thus, neocortical processing of olfactory, but not trigeminally mediated information evidently is affected by functional lesions of the temporal lobe. After olfactory stimulation in patients with a right-sided focus, the distribution of amplitudes was different from normal. Moreover, analyses showed nonoverlapping 95% confidence intervals (CI) for latency N1 when vanillin was applied to the right nostril. These results indicate that RTL may play a different role in processing of olfactory information as compared with LTL.

Oxymetazoline appeared to have neither negative nor major positive effects on intranasal chemosensory function. It is hypothesized that oxymetazoline needs to be applied locally to the area of the olfactory cleft in order to significantly improve olfaction during the course of the common cold.