Retronasal olfactory function: Clinical use of the "Guttich"-test in the diagnostics of olfactory disorders

Citation
T. Hummel et al., Retronasal olfactory function: Clinical use of the "Guttich"-test in the diagnostics of olfactory disorders, LARY RH OTO, 78(11), 1999, pp. 627-631
Citations number
18
Categorie Soggetti
Otolaryngology
Journal title
LARYNGO-RHINO-OTOLOGIE
ISSN journal
09358943 → ACNP
Volume
78
Issue
11
Year of publication
1999
Pages
627 - 631
Database
ISI
SICI code
0935-8943(199911)78:11<627:ROFCUO>2.0.ZU;2-6
Abstract
Background: Testing of retronasal olfactory sensitivity is routinely perfor med in many ENT-departments in German speaking countries. One of the most p opular tests relates to an anecdotal report by Guttich [1]. In this test, l iquids are placed on the patient's tongue; the patient is then asked to des cribe the aroma. Assuming that anosmic patients should not use other descri ptors than ,,sweet,",,sour,",,salty," and ,,bitter", this test design is fr equently applied in disability compensation settings. Surprisingly though, so far there are no studies regarding the sensitivity OF specificity of thi s test in terms of the differentiation between hyposmic and anosmic patient s. Methods: The present investigation was performed in 50 anosmics, 42 hypo smics, and 13 normosmics. The diagnosis ,,hyposmia" or ,,anosmia" was based on 1. the patients' history, 2. psychophysical tests using an established test of olfactory function, the ,,Sniffin' Sticks," and 3. the recording of olfactory evoked potentials. Results: We obtained the following major resu lts: 1. In comparison to hyposmis and normosmics, anosmic patients had grea ter difficulty identifying the aromas. However, correct identification was not always possible for normosmics. 2. Regarding the differentiation betwee n anosmic and hyposmic patients, the test's sensitivity was 86% with a spec ificity of 62%. This clearly limits routine clinical application of this te st. Conclusions: Retronasal testing appears to be an elegant and simple mea ns in order to screen olfactory function. However, the presently investigat ed approach is limited with regard to the discrimination between anosmic an d hyposmic patients.