Effects of olfactory training on posttraumatic olfactory dysfunction: a systematic review and meta-analysis

Area of Science:

• Neurology
• Otolaryngology
• Sensory Science

Background:

• Posttraumatic olfactory dysfunction presents significant clinical challenges due to limited treatment options.
• Olfactory training has demonstrated efficacy across various causes of smell impairment.
• This study evaluates olfactory training's effectiveness specifically for posttraumatic olfactory dysfunction.

Purpose of the Study:

• To systematically review and meta-analyze the impact of olfactory training on patients with posttraumatic olfactory dysfunction.
• To determine the proportion of patients achieving clinically significant improvements in olfaction.
• To assess the change in olfactory test scores following olfactory training.

Main Methods:

• A systematic literature search was performed across major databases (PubMed, Embase, Cochrane Library, Web of Science).
• Studies assessing olfactory changes in posttraumatic patients undergoing olfactory training were included.
• A meta-analysis was conducted on eligible studies, defining clinical significance by specific score improvements (TDI ≥6 or UPSIT ≥4).

Main Results:

• 13 full-text articles were included after reviewing 812 abstracts.
• 36.31% of posttraumatic patients achieved clinically significant olfactory improvements with olfactory training.
• A mean increase of 4.61 in the threshold, discrimination, and identification (TDI) score was observed.

Conclusions:

• Olfactory training represents a potentially effective treatment for posttraumatic olfactory dysfunction.
• Further high-quality, controlled studies are necessary to fully elucidate its effects on overall olfactory performance and specific subcomponents.