Evaluation of chemosensory function in patients with upper respiratory tract post-viral olfactory dysfunction / 中华耳鼻咽喉头颈外科杂志

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.

Study on the clinical characteristics of isolated congenital anosmia / 中华耳鼻咽喉头颈外科杂志

Objective: To retrospectively analysely the electrophysiological and imaging features of isolated congenital anosmia (ICA) and to assess the clinical phenotypic characteristics and classification of ICA. Methods: Clinical data of 30 ICA patients in Beijing Anzhen Hospital from 2012 to 2019 was retrospectively reviewed, including 13 males and 17 females, aged (35±19) years. The control group consisted of 30 healthy people from medical examination center, including 13 males and 17 females, aged (39±14) years. The clinical characteristics of ICA were analyzed using Sniffin' Sticks test, olfactory event-related potentials (oERPs), trigeminal event-related potentials (tERP) and olfactory pathway MRI. SPSS 17.0 software was used to compare the difference of olfactory function between the two groups. The correlation between olfactory bulb, olfactory sulcus structure and age was observed, and the clinical phenotype characteristics of ICA patients were analyzed. Results: The subjective olfactory function was completely lost in ICA patients. oERP was absent in all of the ICA patients, but showed normal N1 and P2 waves in controls. tERP could be evoked in 63.3% (19/30) of ICA patients, and signals in these patients showed higher amplitude in the N1 ((-10.33±6.93) μV vs (-5.11±2.71) μV, t=-10.113, P<0.01) and P2 ((+17.25±8.51) μV vs (+7.31±3.46) μV, t=5.443, P<0.01) waves than that of the controls. Olfactory bulbs were aplastic in 80.0% (24/30) of patients and hypoplastic in 20.0% (6/30) of patients. Fifty-six point seven percent (17/30) of patients had bilateral olfactory sulcus deletion while 43.3% (13/30) had dysplasia, and all of the patients exhibited a depth of olfactory sulcus less than 8 mm. Both the structure of olfactory bulbs and olfactory sulcus were not associated with age for ICA patients (r value was -0.174 and 0.325, respectively, all P>0.05). Conclusions: ICA patients show neurophysiologic deficits and some anatomic differences compared with healthy controls. The absence of oERP combining with a depth of olfactory sulcus less than 8 mm is the important indicator for clinical diagnosis of ICA. The structure of olfactory bulb may be a critical factor for clinical classification of ICA.

Preliminary study of DTI on cerebral white matter micro-structure of patients with idiopathic olfactory loss / 临床耳鼻咽喉头颈外科杂志

OBJECTIVES@#To investigate the cerebral white matter micro-structure in patients with idiopathic olfactory loss using diffusion tensor imaging (DTI).@*METHODS@#Sixteen patients with idiopathic olfactory loss and sixteen normal subjects matched by age and sex were recruited in this study. Sniffin'Stick olfactory test was performed to evaluate the olfactory function of all subjects. We acquired diffusion tensor images with an echo planar imaging (EPI) sequence from all subject on a 3T scanner. The fractional anisotropy (FA) images were performed using DTI-studio, and bilateral Piriform cortex, Orbitofrontal cortex, Hippocampus and Insula cortex adjacent white matter and Capsula interna were delineated as the region of interesting (ROI), the FA for each ROI was calculated. Independent sample t test analysis was used to compare the FA value of all ROIs between the controls and patients. In addition, correlation analysis between FA value and MMSE score in patients were conducted.@*RESULTS@#Compared with the controls, patients showed significantly decreased FA value in the adjacent white matter of bilateral Piriform cortex, Orbitofrontal cortex, Hippocampus and Insula cortex (0.05).@*CONCLUSIONS@#The patients with idiopathic olfactory loss show the damage of white matter micro-structure in the olfactory center, which could be important for the pathogenesis study and early intervention of idiopathic olfactory loss.