Olfactory cleft evaluation: a predictor for olfactory function in smell-impaired patients?

Abstract

Objective: In this study, we introduce an extension of previous work by Soler et al. (Int Forum Allergy Rhinol 6(3):293–298, 2016) on a modified endoscopic scoring system of the Lund–Kennedy Score (focusing on the olfactory cleft) to evaluate its correlation with the olfactory function in patients with various smell disorders. Study design: A prospective cohort study. Methods: Two-hundred and eighty-eight participants were included and categorized in five groups according to the cause of their olfactory disorder: (0) control, (1) idiopathic, (2) sino-nasal, (3) postinfectious and (4) post traumatic olfactory loss. Olfaction was evaluated using the “Sniffin’ Sticks” test. The classical Lund–Kennedy scoring and a new olfactory cleft specific Lund–Kennedy scoring (OC–LK) were performed to evaluate mucosal changes. Results: Significantly higher OC–LK scores on both sides were found in smell-impaired patients as compared to normosmic controls. When comparing the 4 groups, a significant difference of the OC–LK score were present between the sino-nasal and all other groups. Most importantly, significant negative correlations with strong effects were shown in the sino-nasal group between the OC–LK score and odor discrimination and odor identification. However, no such correlation emerged between the classical LK score and smell function. Conclusion: Olfactory cleft evaluation using the OC–LK score correlates with the olfactory function in patients with sino-nasal smell disorder. This diagnostic tool may reflect the underlying pathophysiological mechanism of sino-nasal smell loss, and therefore, should complement olfactory diagnostics in patients with sino-nasal smell disorder.