Long term effects of olfactory training in patients with post-infectious olfactory loss

Rhinology. 2016 Jun;54(2):170-5. doi: 10.4193/Rhin15.264.

Abstract

Background: There is evidence of the effectiveness of repeated exposure to odours on short-term olfactory function. The aim of this study was to assess the long-term effects of olfactory training.

Methods: We conducted a prospective study of 111 patients with post-infectious olfactory dysfunction. Two groups of patients performed olfactory training for 16 and 56 weeks, respectively, and were compared with a control group. The training was performed twice daily using four odours (phenyl ethyl alcohol, eucalyptol, citronellal, eugenol). Olfactory testing was performed by means of the Sniffin Sticks test as a baseline assessment and then every 8 weeks for 56 weeks. Subjective ratings were performed using a visual analogue scale (0-100).

Results: Both training groups presented significantly higher scores than the controls. The long-term group had better results than the short-term group. Short-term training patients sustained their improvement within the follow-up period. Subsets analysis showed that training patients mainly increased identification and discrimination. Subjective ratings were in accordance with the olfactory test results.

Conclusion: Long-term olfactory training seems to be associated with better results in patients with post-infectious olfactory loss than a short-term scheme. Short-term training provides sustainable results at 56 weeks follow-up assessment.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Acyclic Monoterpenes
  • Adult
  • Aged
  • Aldehydes
  • Cyclohexanols
  • Discrimination, Psychological
  • Eucalyptol
  • Eugenol
  • Female
  • Humans
  • Male
  • Middle Aged
  • Monoterpenes
  • Odorants*
  • Olfaction Disorders / etiology
  • Olfaction Disorders / rehabilitation*
  • Phenylethyl Alcohol
  • Recovery of Function*
  • Respiratory Tract Infections / complications*
  • Sensory Thresholds

Substances

  • Acyclic Monoterpenes
  • Aldehydes
  • Cyclohexanols
  • Monoterpenes
  • Eugenol
  • Phenylethyl Alcohol
  • citronellal
  • Eucalyptol