Effects of olfactory training in patients with olfactory loss.
OBJECTIVE
Olfactory function is known to be modulated by repeated exposure to odors. The aim of this investigation was whether patients with olfactory loss would benefit from "Training" with odors in terms of an improvement of their general olfactory function. It was hypothesized that olfactory Training should produce both an improved sensitivity towards the odors used in the Training process and an overall increase of olfactory function.


METHODS
The prospective study was performed in patients with olfactory dysfunction.


METHODS
One group of patients performed the Training (n = 40), whereas another part did not (n = 16). Exclusion criteria for patients were sinunasal disease. Olfactory training was performed over a period of 12 weeks. Patients exposed themselves twice daily to four intense odors (phenyl ethyl alcohol: rose, eucalyptol: eucalyptus, citronellal: lemon, and eugenol: cloves). Olfactory testing was performed before and after training using the "Sniffin' Sticks" (thresholds for phenyl ethyl alcohol, tests for odor discrimination and odor identification) in addition to threshold tests for the odors used in the training process.


RESULTS
Compared to baseline, training patients experienced an increase in their olfactory function, which was observed for the Sniffin' Sticks test score and for thresholds for the odors used in the training process. In contrast, olfactory function was unchanged in patients who did not perform olfactory training. The present results indicate that the structured, short-term exposure to selected odors may increase olfactory sensitivity.
Hummel
Thomas
T
Department of Otorhinolaryngology, Smell & Taste Clinic, University of Dresden Medical School, Dresden, Germany. thummel@mail.zih.tu-dresden.de
Rissom
Karo
K
Reden
Jens
J
Hähner
Aantje
A
Weidenbecher
Mark
M
Hüttenbrink
Karl-Bernd
KB
D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009812:Odorants; D000857:Olfaction Disorders / Q000503:physiopathology / Q000534:rehabilitation*; D011446:Prospective Studies; D013811:Psychotherapeutic Processes; D020127:Recovery of Function / Q000502:physiology; D012903:Smell / Q000502:physiology*; D016896:Treatment Outcome; D055815:Young Adult