Can immersive olfactory training serve as an alternative treatment for patients with smell dysfunction?

Abstract

Abstract Objectives Olfactory training (OT) has emerged as a first‐line therapeutic approach to the management of olfactory dysfunction. Conventional OT (COT) involves the systematic home‐based exposure to four distinct odors. Previous research has demonstrated that immersive OT (IOT) involving full‐body exposure to dozens of distinct odors could also improve overall olfactory function. This study compared IOT and COT in terms of efficacy. Methods A total of 60 patients were enrolled and assigned to three groups. The IOT group (n = 25) underwent immersive exposure to 64 odors once daily in a specialized theater. COT participants (n = 17) sniffed four typical odors in a set of four jars twice daily at home. A control group (n = 18) underwent passive observation. Olfactory function was assessed before and after training. Results Significant improvements in composite threshold‐discrimination‐identification (TDI) scores were observed after training in both the IOT (mean difference = 2.5 ± 1.1. p = .030) and COT (mean difference = 4.2 ± 1.3, p = .002) groups. No changes were observed in the control group. A significantly higher proportion of patients in the COT group (41%) presented improvements of clinical importance (TDI ≥5.5) compared to the controls (p = .018). The improvements attained in the IOT group (20%) were less pronounced (p = .38). Conclusion While IOT did not exhibit the same efficacy as COT in restoring olfactory function, it still demonstrated promising outcomes. Future efforts to advance olfactory recovery should focus on cross‐modal integration. Level of Evidence Level 3.

Keywords

• olfactory dysfunction
• olfactory training
• Sniffin' Sticks