12-Item Odor Identification Test Applied In The Olfactory Assessment Of Parkinson's Disease

Olfactory dysfunction is common in Parkinson ' s disease(PD)with a prevalence between 70 and 90%,it appears before motor symptoms and becomes one of the earliest non-motor symptoms.Olfactory detection is of great value in the early diagnosis and differential diagnosis of Parkinson's disease.At present the study of olfactory in China is relatively few,and there is no unified method to evaluate olfactory function.Aim:Using 12-item odor identification test to evaluate olfactory function of Parkinson ' s disease in China;To explore the incidence of olfactory dysfunction in patients with Parkinson's disease as well as the relationship between olfactory function and age,gender,education,smoking,disease duration,Hohn-Yahr stage,UPDRS ?scores and the dosage of levodopa.Methods:Through the case-control study,we used the12-item odor identification test(SS-12)to evaluate the olfactory function of 106 patients with Parkinson's disease and 110 healthy volunteers,and analyzed the olfactory function in the two groups,as well as the correlation between olfactory scores and age,gender,education,smoking,disease duration,Hohn-Yahr stage,UPDRS ? scores and the dosage of levodopa in the two groups.Results:Mean identification scores in patients(5.97±2.27)were significantly lower than in controls(8.04±2.00),difference was statistically significant(t = 7.108,P = 7.108).Parkinson's disease group did worse than the control group in identifying peppermint,bananas,liquorice,coffee,pineapple,rose,fish,difference was statistically significant(P<0.05),and there was no significant difference of the two groups in identifying orange,leather,cinnamon,lemon,clove(P>0.05).Receiver Operating Characteristic curves revealed 67.3% sensitivity and 73.6% specificity in separating PD and healthy controls with a cut-off value of 7.5.Regarding 7.5 as Olfactory dysfunction diagnostic boundary value,73.6% of the patients had an impairment of odor identification.Correlation analysis showed that gender(rs= 0.243,P=0.012),education(rs=0.208,P=0.032)and smoking(rs=0.279,P=0.279)were associated with odor identification ability,while age,disease duration,Hohn-Yahr stage,UPDRS ? scores and the dosage of levodopa were not related with odoridentification ability(P>0.05)in Parkinson's disease.In the control group,age(rs=0.283,P=0.283)and education were associated with odor identification ability(rs=0.363,P=0.363),while gender and smoking were unrelated.(P>0.05).Conclusion:Olfactory dysfunction occurs in Parkinson's disease with an incidence rate of 73.6%;As a simple,quick and economic method to detect olfactory function,SS-12 is suitable to use in the olfactory assessment of Parkinson's disease in China,with 67.3% sensitivity and 73.6% specificity in separating Parkinson's disease and healthy controls.Olfactory function may be related to age,gender,education and smoking,but has nothing to do with disease duration,Hohn-Yahr stage,UPDRS ? scores and the dosage of levodopa in Parkinson's disease.