Assessing olfactory function in laryngectomees using the sniffin’sticks test battery and chemosensory evoked potentials

Abstract

Objectives/Hypothesis:Laryngectomees are often considered to be completely anosmic. The aim of this study was to determine whether anosmia in laryngectomees reflects diminished transport of odorants to the olfactory epithelium or olfactory epithelial damage. Study Design:Twenty-five laryngectomees were examined psychophysically using the Sniffin’Sticks test battery. All patients rated the degree of their subjectively perceived deficit on a rating scale. Chemosensory evoked potentials were also recorded in 11 of 25 patients. Results:Sixteen patients complained very little about their smell deficit, even though the psychophysical testing found 18 patients to be anosmic and 7 hyposmic. Olfactory potentials could be recorded in only 7 of the 11 patients who received this evaluation, despite the fact that all 11 perceived, at least vaguely, the olfactory stimulus, H2S, during the recording sessions. No meaningful correlation between the psychophysical and electrophysiological data was observed. Conclusions:The psychophysical data revealed the laryngectomees to be either functionally anosmic or hyposmic. The olfactory evoked potential data suggested that at least in two thirds of the laryngectomized patients the olfactory system had some function, even up to 22 years after surgery. Because patients in everyday situations find ways to bring odorants to the olfactory mucosa, the low number of complaints about subjectively perceived deficits is reasonable. © 2000 Lippincott Williams and Wilkins, Inc.