Consistency And Stability Of Three Motor Subtype Classifications In De Novo Parkinson’s Disease Patients

Background and objective:Motor subtype is the most commonly used clinical subtype of Parkinson’s disease（PD）.At present,three different motor subtype classifications are widely used in clinical and scientific research of PD.The purposes of this study were to investigate the baseline consistency and follow-up stability of three motor phenotype classifications in newly diagnosed PD patients,as well as the factors affecting the stability of PD motor subtypes.Methods:A total of 283 de novo PD patients were enrolled in this study,of which 79patients were followed up for 1 month.Patients with PD were divided into three groups according to three motor subtype classification methods,namely,tremor-dominant/indeterminate/postural instability and gait difficulty（TD/IND/PIGD）proposed by Jankovic,and two classifications of TD/mixed/akinetic-rigid（TD/MIX/AR）proposed by Schiess and Kang respectively.Cohen’s kappa coefficient（κ）was used to evaluate the consistency of the three motor subtype classification methods at baseline.79 patients with PD were divided into stable group and unstable group,and the demographic and clinical data of the two groups were compared by two-sample t-test,Mann-Whitney U test or chi-square test.Results:There was fair consistency between the Jankovic,Schiess,and Kang classifications(κ_S=0.383±0.044,κ_K=0.360±0.042,κ_SK=0.368±0.038).Among the three classification methods of motor subtypes,from baseline to 1-month follow-up,PD patients with stable motor subtypes were the most in Schiess classification,while PD patients with stable motor subtypes were the least in Jankovic classification.Furthermore,in the Jankovic classification,the baseline demographic and clinical characteristics between the stable group and the unstable group were compared.It was found that only the non-motor symptoms questionnaire（NMSQuest）scores were significantly different between the two groups（P=0.008）,and the NMSQuest scores of the stable group were higher than that of the unstable group.Conclusion:The consistency between Jankovic,Schiess and Kang classification systems was fair.In addition,this study found for the first time that non-motor symptoms（NMSs）influenced the stability of Jankovic classification.Our findings strongly support the combination of NMSs and motor symptoms to define PD subtypes to improve the effectiveness of the PD phenotype.