Objective:The purpose of this study was to compare the olfactory function examination results of patients with post-viral olfactory dysfunction（PVOD） in different prognostic groups and analyze prognostic factors, especially the influence of olfactory bulb volume（OBV） on prognosis, so as to provide objective basis for clinical diagnosis and treatment. Methods:After approval by the hospital ethics committee, the patients with PVOD admitted to Beijing Anzhen Hospital's outpatient department from January 2019 to December 2019 were followed up for at least 1 year. These patients completed the Sniffin' Sticks test and MRI examination of the olfactory pathway before treatment. According to the results of the Sniffin' Sticks test after 1 year follow-up（threshold-discrimination-identification（TDI） score of the patients was increased at least 6 points）, the patients were divided into two groups as the improvement group and the non-improvement group. The prognostic factors of PVOD patients were preliminarily determined by comparing the differences of various factors and the results of olfactory function examination between the two groups. Results:In this study, 47 patients with PVOD were included, with the smell improvement rate was 53.2%. Compared with the improvement group, the patients in the non-improvement group had longer duration, poorer initial olfactory function, higher olfactory threshold, and poorer olfactory discrimination and recognition ability（All P<0.01）. There was no statistical difference in terms of gender, age, allergic rhinitis and smoking between the two groups（All P>0.05）.The OBV of the non-improvement group was （59.48±23.92） mm³, which was significantly lower than that in the improvement group（[92.77±14.35]mm³, P<0.001）. Multiple logistic regression analysis showed that prognostic factors included course of disease（OR 0.677, 95%CI 0.461-0.993, P=0.046）, initial T value（OR 263.806, 95%CI 1.028-67 675.884, P=0.049） and OBV（OR 1.160, 95%CI 1.002-1.343, P=0.047）. The area under the receiver operating characteristic curve（ROC curve） of OBV was 0.888（0.797-0.979, P<0.001）. The correct diagnostic index of OBV≥78.50 mm³was used to determine the prognosis of olfactory function, with a specificity of 0.818 and a sensitivity of 0.840. The ROC curve analysis showed that the area under the ROC curve of duration was 0.822（0.703-0.940, P<0.001）. The correct diagnostic index of the duration ≤6 months was used to determine the prognosis of olfactory function, with a specificity of 0.727 and a sensitivity of 0.800. The area of T score was 0.793（0.662-0.924, P=0.001）. T score ≥1.25 was used as the correct diagnostic index to determine the prognosis of olfactory function. The specificity and sensitivity were 0.818 and 0.680, respectively. Conclusion:The prognosis of olfactory function in PVOD patients is related to the course of disease, the degree of olfactory loss and OBV. Those with no improvement in olfactory function have a longer disease course, aggravated olfactory damage and reduced OBV than those with improved olfactory function. The factors of Duration ≤6 months, T value ≥1.25 and OBV≥78.50 mm³suggested better prognosis, and the results of objective olfactory examination have greater value in evaluating the prognosis of olfactory function.
目的：比较上呼吸道感染后嗅觉障碍（PVOD）患者不同预后组间的嗅觉功能检查结果，分析预后相关因素，尤其嗅球体积（OBV）对预后的影响，为临床诊疗提供客观依据。 方法：对2019年1月—2019年12月于北京安贞医院门诊就诊的PVOD患者进行≥1年的随访，这些患者在治疗前完成Sniffin'Sticks嗅觉测试、嗅通路MRI检查。根据1年随访期后Sniffin'Sticks嗅觉测试结果总分提高≥6分，将患者分为嗅觉功能改善组和嗅觉功能无改善组。比较两组间各因素和嗅觉功能检查结果的差异，初步确定影响PVOD患者的预后因素。 结果：共纳入47例PVOD患者，Sniffin'Sticks嗅觉测试复查结果显示嗅觉改善率为53.2%。与嗅觉功能改善组相比，嗅觉功能无改善组患者病程长，初始嗅觉功能差，嗅觉阈值高，嗅觉辨别和识别能力差（均P<0.01）。两组在性别、年龄、变应性鼻炎和吸烟方面差异均无统计学意义（均P>0.05）。嗅觉功能无改善组的OBV为（59.48±23.92） mm³，明显小于嗅觉功能改善组[（92.77±14.35） mm³]。经多元logistic回归分析预后相关因素包括病程（OR 0.677，95%CI 0.461~0.993，P=0.046），初始T值（OR 263.806，95%CI 1.028~67 675.884，P=0.049）和OBV（OR 1.160，95%CI 1.002~1.343，P=0.047）。ROC曲线分析结果显示，OBV在ROC曲线下面积为0.888（0.797~0.979，P<0.001），以OBV≥78.50 mm³ 正确诊断指数判断嗅觉功能预后良好，其特异性为0.818，敏感性为0.840；病程因素ROC曲线下面积为0.822（0.703~0.940，P<0.001），以病程≤6个月为正确诊断指数判断嗅觉功能预后良好，其特异性为0.727，敏感性为0.800；T值ROC曲线下面积为0.793（0.662~0.924，P=0.001），以T值≥1.25为正确诊断指数判断嗅觉功能预后较好，其特异性为0.818，敏感性为0.680。 结论：PVOD患者嗅觉功能预后与病程、嗅觉损伤程度和OBV有关。嗅觉功能无改善者较嗅觉功能改善者病程延长，嗅觉损伤程度加重和OBV减小。病程≤6个月，T值≥1.25和OBV≥78.50 mm³均提示预后良好，且客观嗅觉检查结果对嗅觉功能预后的评估价值更大。.
Keywords: Sniffin'Sticks test; olfactory bulb volume; olfactory training; post-viral olfactory dysfunction; prognosis.
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