Objective:This study aims to evaluate the nasal structural and electrophysiological features of patients with postoperative olfactory dysfunction following aesthetic rhinoplasty.Methods:We retrospectively analyzed the clinical features of 30 outpatients (females, aged 33±6 years) from Beijing Anzhen Hospital and China-Japan Friendship Hospital between 2014 and 2023, who complained of olfactory dysfunction following aesthetic rhinoplasty. The control group was 30 healthy females aged 32±9 years. Psychophysical olfactory test (Sniffin′ Sticks, SS), olfactory and trigeminal event-related potentials (oERPs and tERPs), and acoustic rhinometry were used for evaluating the olfactory function and nasal structure in patients and healthy controls. SPSS 17.0 software was used to compare the difference in olfactory function and nasal structure between the two groups and to analyze the factors related postoperative olfactory dysfunction.Results:There was a significant difference in the scores on psychophysical olfactory test between the patients and controls (10.78±3.90 vs. 33.66±2.42, t=-23.35, P<0.001). ERPs could be evoked in all patients and controls. Patients showed higher amplitudes of N 1 waves in both oERPs and tERPs than controls ( P<0.05 for all), but no differences in the latencies of N 1 and P 2 waves or in the amplitudes of P 2 waves were observed between the two groups ( P>0.05 for all). There was no difference in nasal structure between the two groups ( P>0.05). However, after nasal decongestant, mucosal congestion in the cross-sectional area (CSA) from the nostril to 6 cm level was found more significantly in patients than controls (nasal congestion index 40.00% vs. 1.00%, t=2.09, P=0.047). Better olfactory function was associated with increasing nasal volumes, increasing nasal threshold and anterior nasal turbinate plane CSA( P<0.05 for all). Conclusion:The important factor related to olfactory dysfunction following aesthetic rhinoplasty may be attributed to local mucosal congestion, rather than nasal structural alteration or neurophysiologic deficits in the olfactory pathway.

Objective:To explore the alterations in gray matter morphology and contributing factors in patients with post-infectious olfactory dysfunction (PIOD) using voxel-based morphometry (VBM) and surface-based morphometry (SBM), thereby providing scientific insights into the neuropathological mechanisms underlying PIOD.Methods:A total of 46 PIOD patients (PIOD group) and 46 normosmic volunteers (control group) were recruited from the Smell and Taste Disorders Clinic of Beijing Anzhen Hospital, Capital Medical University, between January 2020 and December 2024. All participants underwent olfactory psychophysical tests (Sniffin′ Sticks) and olfactory event-related potential (oERP) examination. High-resolution T1-weighted 3D MRI structural images were obtained for both groups. VBM was employed to analyze inter-group differences in gray matter volume, while SBM was used to assess cortical thickness and folding index. Correlations between gray matter volume in significant difference brain regions and disease duration, Sniffin′ Sticks scores, oERP parameters were analyzed. A two-tailed P<0.05 was considered statistically significant. Results:No significant differences were observed in age, sex, education level, or Mini-Mental State Examination (MMSE) scores ( t=1.80, χ2=0.41, t=0.17, t=1.77, all P>0.05). Compared with controls, the PIOD group showed significantly lower Sniffin′ Sticks scores ( t=28.70, P<0.001), prolonged oERP latencies and reduced amplitudes (all P<0.001). VBM revealed significantly reduced gray matter volume in the right orbitofrontal cortex (OFC) in the PIOD group ( t=5.38, P<0.001). SBM demonstrated decreased cortical thickness in the right OFC ( t=5.27, P<0.001), with no significant differences in folding index. The gray matter volume in the right OFC was negatively correlated with disease duration ( r=-0.61, P<0.001), but no significant correlations were found with Sniffin′ Sticks scores or oERP parameters. Conclusion:Patients with PIOD show atrophy in the right OFC, which correlates with disease duration, suggesting that persistent olfactory dysfunction may be associated with neurodegenerative changes.

Objective:This study aims to evaluate the nasal structural and electrophysiological features of patients with postoperative olfactory dysfunction following aesthetic rhinoplasty.Methods:We retrospectively analyzed the clinical features of 30 outpatients (females, aged 33±6 years) from Beijing Anzhen Hospital and China-Japan Friendship Hospital between 2014 and 2023, who complained of olfactory dysfunction following aesthetic rhinoplasty. The control group was 30 healthy females aged 32±9 years. Psychophysical olfactory test (Sniffin′ Sticks, SS), olfactory and trigeminal event-related potentials (oERPs and tERPs), and acoustic rhinometry were used for evaluating the olfactory function and nasal structure in patients and healthy controls. SPSS 17.0 software was used to compare the difference in olfactory function and nasal structure between the two groups and to analyze the factors related postoperative olfactory dysfunction.Results:There was a significant difference in the scores on psychophysical olfactory test between the patients and controls (10.78±3.90 vs. 33.66±2.42, t=-23.35, P<0.001). ERPs could be evoked in all patients and controls. Patients showed higher amplitudes of N 1 waves in both oERPs and tERPs than controls ( P<0.05 for all), but no differences in the latencies of N 1 and P 2 waves or in the amplitudes of P 2 waves were observed between the two groups ( P>0.05 for all). There was no difference in nasal structure between the two groups ( P>0.05). However, after nasal decongestant, mucosal congestion in the cross-sectional area (CSA) from the nostril to 6 cm level was found more significantly in patients than controls (nasal congestion index 40.00% vs. 1.00%, t=2.09, P=0.047). Better olfactory function was associated with increasing nasal volumes, increasing nasal threshold and anterior nasal turbinate plane CSA( P<0.05 for all). Conclusion:The important factor related to olfactory dysfunction following aesthetic rhinoplasty may be attributed to local mucosal congestion, rather than nasal structural alteration or neurophysiologic deficits in the olfactory pathway.

Objective:To explore the alterations in gray matter morphology and contributing factors in patients with post-infectious olfactory dysfunction (PIOD) using voxel-based morphometry (VBM) and surface-based morphometry (SBM), thereby providing scientific insights into the neuropathological mechanisms underlying PIOD.Methods:A total of 46 PIOD patients (PIOD group) and 46 normosmic volunteers (control group) were recruited from the Smell and Taste Disorders Clinic of Beijing Anzhen Hospital, Capital Medical University, between January 2020 and December 2024. All participants underwent olfactory psychophysical tests (Sniffin′ Sticks) and olfactory event-related potential (oERP) examination. High-resolution T1-weighted 3D MRI structural images were obtained for both groups. VBM was employed to analyze inter-group differences in gray matter volume, while SBM was used to assess cortical thickness and folding index. Correlations between gray matter volume in significant difference brain regions and disease duration, Sniffin′ Sticks scores, oERP parameters were analyzed. A two-tailed P<0.05 was considered statistically significant. Results:No significant differences were observed in age, sex, education level, or Mini-Mental State Examination (MMSE) scores ( t=1.80, χ2=0.41, t=0.17, t=1.77, all P>0.05). Compared with controls, the PIOD group showed significantly lower Sniffin′ Sticks scores ( t=28.70, P<0.001), prolonged oERP latencies and reduced amplitudes (all P<0.001). VBM revealed significantly reduced gray matter volume in the right orbitofrontal cortex (OFC) in the PIOD group ( t=5.38, P<0.001). SBM demonstrated decreased cortical thickness in the right OFC ( t=5.27, P<0.001), with no significant differences in folding index. The gray matter volume in the right OFC was negatively correlated with disease duration ( r=-0.61, P<0.001), but no significant correlations were found with Sniffin′ Sticks scores or oERP parameters. Conclusion:Patients with PIOD show atrophy in the right OFC, which correlates with disease duration, suggesting that persistent olfactory dysfunction may be associated with neurodegenerative changes.

Objective:To analyze the factors affecting olfactory disfunctions in patients with chronic rhinosinusitis with nasal polyps (CRSwNP).Methods:This was a retrospective analysis. Eighty-eight patients with CRSwNP who underwent endoscopic sinus surgery in Beijing Anzhen Hospital from 2014 to 2018 were enrolled, including 22 males and 66 females, with the age of (48.1±11.3) years old(Mean±SD). Sniffin′ Sticks olfactory test, Lund-Mackay score and modified sinus CT olfactory cleft score, nasal resistance and acoustic reflex examination, blood routine and blood biochemistry test, serum specific IgE test were performed before surgery and nasal polyps of all patients were collected for eosinophil count during surgery. According to bilateral total TDI score, the patients were divided into normal olfactory function group and olfactory disfunction group. The clinical baseline data were compared between the two groups. According to the results of single factor analysis, factors which were significant different between the two groups and clinically useful indicators were further included in the multivariate Logistic regression model analysis, then a model predicting olfactory disfunction in patients with CRSwNP was initially established. P<0.05 was considered statistically significant. Results:Among 88 patients with CRSwNP, 32 (36.4%) patients were with normal olfaction and 56 (63.6%) patients were with olfactory disfunction, including 40 (45.5%) of hyposmia and 16 (18.2%) of anosmia. Tissue eosinophil count, blood eosinophil percentage and blood urea concentration had significant difference between the two groups (12.7[2.0, 52.3]/HP ( M[ P25, P75]) vs 38.6[16.2, 87.0]/HP, 2.75[1.60, 4.80]% vs 4.35[2.50, 6.60]%, (5.56±1.15) mmol/L vs (4.98±1.33) mmol/L, all P<0.05). Modified sinus CT olfactory cleft score and Lund-Mackay score except for ostiomeatal complex score were statistically significant between the two groups (all P<0.05). Multivariate Logistic regression analysis showed that the bilateral and total olfactory cleft score and blood urea concentration were statistically significant, in addition, the bilateral and total olfactory cleft score was a risk factor ( OR=2.108, 95 %CI: 1.407-3.159, P<0.001) and blood urea within a certain concentration was a protective factor ( OR=0.461, 95 %CI: 0.240-0.884, P=0.020). Further studies found that the area under the ROC curve of the model with tissue eosinophil count, blood eosinophil percentage, bilateral and total olfactory cleft score, total inspiratory volume and blood urea concentration was 0.888 ( P<0.01), which had good predictive value for olfactory disorders in CRSwNP. Conclusions:The modified sinus CT olfactory cleft score is closely related to the olfactory disorders in patients with CRSwNP. A certain degree of elevated blood urea concentration may have a protective effect on the olfactory function of patients with CRSwNP.

Objective: To explore the clinical effects and the influence factors of olfactory training in the treatment of olfactory dysfunction. Methods: A total of 86 patients with olfactory dysfunction (49 post-infectious and 37 post-traumatic) in Beijing Anzhen Hospital during Dec 2016 to May 2017 were recruited in this prospective study. The clinical data of patients were analyzed, including gender, age, body mass index (BMI), course of disease, smoking history, drinking history, diabetes history, hypertension history, hyperlipidemia history, and anxiety visual analogue score (VAS). All patients were treated with olfactory training for 16 weeks, and all of them underwent Sniffin′ Sticks olfactory test before and after treatment, which was evaluated by composite threshold-discrimination-identification score (TDI). SPSS 23.0 software, paired t test and univariate and multivariate Logistic regression analysis were used to analyze the data. Results: Eighty patients received treatment, including 46 post-infectious olfactory dysfunction and 34 post-traumatic olfactory dysfunction. After olfactory training, the total scores of TDI increased with statistically significant (18.3±8.6 vs 13.6±7.4, t=-6.158, P<0.05). The overall efficacy was 40% (32/80). The effective rate were 45.7% (21/46) in post-infectious olfactory dysfunction and 32.4% (11/34) in post-traumatic olfactory dysfunction respectively, with no statistically significant difference (χ²=1.441, P=0.230). Logistic regression analysis showed that the course of disease was an influence factor in the clinical curative effect (OR=0.881, 95%CI: 0.799-0.973, P=0.012). In patients with less than a year of olfactory dysfunction, the olfactory function improved obviously with the efficiency of 50.9% (29/57). Conclusion Sixteen weeks of olfactory training provides a significant therapeutic effect on the post-infectious and post-traumatic olfactory dysfunction, and the olfactory training can achieve better therapeutic effects at the early stage.

Objective: To investigate the brain volume alterations in patients with hyposmia using voxel-based morphometry (VBM) and to correlate these alterations with the degree and duration of hyposmia. Methods: Forty patients with hyposmia from Department of Otorhinolaryngology Head and Neck Surgery, Beijing Anzhen Hospital since 2013 to 2016 and forty age and sex matched normal subjects were recruited in this study. Sniffin′ Sticks olfactory test was performed to evaluate the olfactory function of all subjects. We acquired T1-weighted magnetic resonance images from all subject on a 3T scanner. VBM was performed using VBM8 toolbox and SPM8 in a Matlab environment. Independent sample t test analysis was used to compare the volume of gray and white matter between the controls and patients. In addition, the Pearson or Spearman correlation analysis was used for the correlation between the voxel value of cerebral volume alterations area and the degree and duration of hyposmia on patients (threshold discrimination identification, TDI). Results: Compared with the controls, patients showed significantly decreased volume in the gray matter of right orbitofrontal cortex (number of voxel in clusters was 226, t=-4.46, P<0.001, uncorrected). There was negative correlation between decreased gray matter volume of the right orbitofrontal cortex with significantly decreased area and the TDI results (r=-0.40, P=0.01), but positive correlation with duration of hyposmia (r=0.37, P=0.02). Conclusions The patients with hyposmia show gray matter atrophy of the right orbitofrontal cortex. The duration may be an important risk factor for decreased gray matter in patients with hyposmia.

Objective: To investigate the white matter integrity in patients with olfactory dysfunction using diffusion tensor imaging (DTI). Methods: Twenty-one patients with olfactory dysfunction and sixteen age, sex and level of education matched normal subjects were recruited in this study. Sniffin′ Sticks olfactory test was performed to evaluate the olfactory function of all subjects. We acquired diffusion tensor images with a echo planar imaging (EPI) sequence from all subjects 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 as well as capsula interna were delineated from the FA images as the region of interest associated with olfactory (ROI_awo) manually. Independent sample t test analysis was used to compare the FA value of all ROI_awo between the controls and patients. Results: In olfactory dysfunction group, the FA value of adjacent white matter of right piriform cortex and orbitofrontal cortex were significantly lower than those of control group (0.42±0.05 (±s) vs 0.45±0.05, 0.43±0.06 vs 0.49±0.07, t value was 2.32, 2.79, respectively, all P<0.05). The FA value of adjacent white matter of left piriform cortex and orbitofrontal cortex had no significant difference compared with those of control group (0.43±0.05 vs 0.45±0.04, 0.44±0.04 vs 0.47±0.06, t value was 1.65, 1.37, respectively, all P>0.05). The FA value of the adjacent white matter of bilateral hippocampus, insula cortex and capsula interna had no significant difference compared with those of control group, neither (0.45±0.08 vs 0.44±0.08, 0.45±0.09 vs 0.44±0.10, 0.41±0.08 vs 0.39±0.07, 0.41±0.07 vs 0.38±0.05, 0.64±0.08 vs 0.63±0.08, 0.64±0.07 vs 0.63±0.07, t value was 0.30, 0.15, 0.88, 1.34, 0.14, 0.35, respectively, all P>0.05). Conclusions The patients with olfactory dysfunction showed abnormal white matter connection in the major primary and secondary olfactory cortex. The reduced white matter integrity in ROI_awo might contribute to the pathogenesis of olfactory dysfunction.

Objective: Using ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) and microPET-CT to test the feasibility of ¹⁸F-FDG PET-CT for validation of olfactory function of rats with standard phenethyl alcohol (PEA) and isovaleric acid (IVA) odors stimulation. To verify the possibility of ¹⁸F-FDG PET-CT as a new objective examination method for olfactory function. Methods: Six healthy Sprague-Dawley (SD) male rats were selected with a weight of 250-300 g. First of all, buried food pellet test (BFT) was used to confirm the normal olfactory function of rats. Then in the next 3 days, after the intravenous injection of ¹⁸F-FDG (18 MBq/100 g), awaken rats were placed in a ventilated plexiglas cage for 30 min. Subsequently, pure air (the first day), PEA (the second day) and IVA (the third day) were delivered. After odor stimulation for 30 min, rats were performed by a static PET-CT under anesthesia. Images reconstructed were assessed by SPM method and analyzed by VBM method. Data was analysied by paired t test. Results: Activation regions of rat′s brain after PEA stimulation included bed nucleus and insula. Activation regions of rat′s brain after IVA stimulation included olfactory bulb, anterior olfactory nucleus, amygdala, entorhinal cortex, olfactory cortex, piriform cortex, insula, prefrontal cortex, cingulate cortex and bed nucleus (P<0.005, Ke>20 voxels). Conclusions Through microPET-CT, we can observe that olfactory stimulation with different odors can induce metabolic activation in different regions of rat′s brain, which was in concordance with olfactory regions. The olfactory related brain regions of rats have strong responses to odor stimulation of IVA.