Four odorants for olfactory training are enough: a pilot study

Area of Science:

• Otolaryngology
• Neuroscience
• Sensory Science

Background:

• Olfactory training (OT) is a common treatment for olfactory disorders, but optimal regimens are debated.
• This study compares 3-month OT using 4 versus 7 scent items.

Purpose of the Study:

• To compare the effectiveness of 4-item vs. 7-item olfactory training over 3 months.
• To assess the impact of OT on olfactory function, smell thresholds, and related symptoms.

Main Methods:

• 40 patients with olfactory dysfunction and 60 controls underwent 4-item or 7-item OT (or no OT for controls).
• Assessments included n-butanol TDI score, specific odor thresholds, phantosmia/parosmia, cognitive function, and subjective ratings.
• Measurements were taken before and after the 3-month intervention period.

Main Results:

• Olfactory training (OT) significantly improved TDI scores in patients, irrespective of using 4 or 7 items.
• A clinically significant 5.5-point increase in TDI score correlated with reduced parosmia and improved subjective olfactory function ratings.
• OT outcomes were comparable between the 4-item and 7-item groups.

Conclusions:

• Three months of olfactory training (OT) with either 4 or 7 odors yields similar improvements in olfactory function.
• The number of scent items in OT may not be a critical factor for treatment success, though sample size warrants consideration.