Evaluation of chemosensory function in patients with upper respiratory tract post-viral olfactory dysfunction

Abstract

Objective: To observe the changes of olfactory function, intranasal trigeminal nerve function and taste function in patients with upper respiratory tract post-viral olfactory dysfunction (PVOD), and to explore the correlation of chemosensory function. Methods: The clinical data of 42 patients with PVOD who visited to the Olfactory and Taste Center of Otorhinolaryngology Head and Neck Surgery Department of Beijing Anzhen Hospital from January to December of 2019 were analyzed retrospectively, including 20 males and 22 females, aging (48.86±11.47) years (x¯). Twenty subjects in normal control group were selected according to the sex ratio of PVOD patients. Sniffin' Sticks olfactory tests were performed on the subjects, including threshold test (T), discrimination test (D) and identification test (I), and the sum of the above three test scores was the TDI value. At the same time, olfactory event-related potentials (oERPs), trigeminal event-related potentials (tERPs) and taste function test were performed. According to the taste function test, the patients were divided into normal gustation (NG) group and gustatory dysfunction (GD) group. The results of olfaction, taste and intranasal trigeminal nerve function tests were compared among different groups, and the correlation analysis was carried out. SPSS statistical software was used for statistical analysis. Results: GD was present in 14 (33.3%) of 42 PVOD patients with a course of PVOD of 5 (3, 6) months (M (Q1, Q3)). The gustatory function of patients with PVOD was related to gender (r=0.565, P<0.001), smoking status (r=-0.512, P=0.001), duration (r=-0.357, P=0.020) and olfactory function (all P<0.05). The olfactory function of GD group was worse than that of NG group, and the differences of TDI value and T value between the two groups were statistically significant (10.25±4.58 vs 13.35±3.61, 1.54±0.66 vs 2.10±0.88, t value was 2.40 and 2.10 respectively, both P<0.05). The amplitudes of oERPs and tERPs were significantly lower in GD group than those in NG group (all P<0.05). Conclusion: In patients with PVOD, the subjective and objective olfactory function, intranasal trigeminal nerve function and taste function were decreased, and there was a correlation, suggesting that there was a synergistic effect between the chemosensory functions of PVOD patients.