Office procedures for quantitative assessment of olfactory function.
BACKGROUND
Despite the importance of the sense of smell for establishing the flavor of foods and beverages, as well as protecting against environmental dangers, this primary sensory system is commonly ignored by the rhinologist.


METHODS
In this article basic issues related to practical measurement of olfactory function in the clinic are described and examples of the application of the two most common paradigms for such measurement--odor identification and detection--are presented. A listing is made of the 27 olfactory tests currently used clinically, along with their strengths and weaknesses. A brief review of common nasosinus-related disorders for which quantitative olfactory testing has been performed is provided.


RESULTS
Although many psychophysical tests are available for quantifying olfactory loss, it is apparent that a number are limited in terms of practicality, sensitivity, and reliability. In general, sensitivity and reliability are positively correlated with test length. Given the strengths of the more reliable forced-choice pyschophysical tests and the limitations of electrophysiological tests, the common distinction between "subjective" and "objective" tests is misleading and should not be used. Complete recovery of olfactory function, as measured quantitatively, rarely follows surgical or medical interventions in patients with rhinosinusitis.


CONCLUSIONS
Given the availability of practical clinical olfactory tests, the modern rhinologist can easily quantify cranial nerve (CN) I function. The application of such tests has led to a new understanding of the effects of nasal disease on olfactory function. Except in cases of total or near-total nasal obstruction, olfactory and airway patency measures usually are unrelated, in accord with the concept that rhinosinusitis primarily influences olfactory function by apoptotic pathological changes within the olfactory neuroepithelium.
Doty
Richard L
RL
Smell and Taste Center, Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. doty@mail.med.upenn.edu
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009812:Odorants; D000857:Olfaction Disorders / Q000175:diagnosis*; D011601:Psychophysics; D012903:Smell