Clinical Study Of The Acoustic Characteristics Of Patients With Early Parkinson’s Disease And Atypical Parkinsonism

ObjectiveThis study used acoustic analysis to assess the acoustic characteristics of patients with early Parkinson’s disease(PD)and atypical Parkinson’s syndrome(APS)in terms of vocal pitch variation,articulatory activity and voice quality,to explore parameters that may serve as acoustic markers for disease differentiation,and to assess the feasibility of the markers in conjunction with correlation analysis of clinical factors.Methods1.We enrolled 35 patients with early PD,34 patients with early APS and 30 healthy individuals as the HC group who attended the Second Hospital of Shandong University.We collected the information of age,sex and education level of all individuals,and that of the age of onset,duration of disease of the patients.Parts Ⅱ-Ⅲ of the Unified Parkinson’s Disease Rating Scale(UPDRS)Ⅱ-Ⅲ and the Hoehn-Yahr Scale(H-Y)were used to assess motor systems.The Voice Handicap Index(VHI)was used to assess the degree of subjective voice impairment,and the following scales were checked to assess non-motor symptoms:UPDRS Ⅰ,16-item Parkinson’s Disease Fatigue Scale(PFS-16),Hamilton Anxiety Scale(HAMA),Hamilton Depression Scale(HAMD),Minimum Mental State Examination(MMSE)and Montreal Cognitive Assessment Scale(MOCA).2.Speech recording according to the speech task and the use of Praat software to record the values of the participants’ acoustic parameters.Four pitch variations of the vowel/a/are calculated using the T-value method.In addition,the voice parameters include jitter,shimmer,HNR and intensity of the nine core vowels(/i/,/u/,/ü/,/o/,/e/,/a/,/s/,/zh/,/er/).Based on the first formant(F1)and second formant(F2)of/a/,/i/,/u/,we calculated the Vowel Articulation Index(VAI),the Formant Concentration Ratio(FCR)and Vowel Space Area(VSA),and the Oral Diadochokinesis Rate(DDKr)for the trisyllables/p/,/t/,/k/in a rapid repetitive reading task,all used to assess articulatory organ motility.3.The differences in clinical data and acoustic parameters among the PD,APS and HC groups were compared and inter-group variability analysis was performed.Spearman correlation analysis and stepwise regression were used to investigate the clinical correlates and influencing factors of the differential acoustic parameters to assess their feasibility as discriminative acoustic markers.Results1.In this study,35 patients in the PD group,34 patients in the APS group and 30 people in the HC group are involved.There were no significant differences in gender,education and age among the three groups,or in age of onset and disease duration between the PD and APS groups.UPDRS Ⅰ-Ⅲ and VHI scores in the APS group were significantly higher than the PD group,and MMSE and MOCA scores was significantly lower than the PD group(P<0.05);H-Y stages,HAMD and HAMA scores,were not significantly different between PD and APS groups(P>0.05).2.When it comes to pitch change in the level tone and the falling tone,there was no significant difference among the PD,APS and HC groups(P>0.05),while a significant difference in some segments of the rising and falling-rising tones appeared(P<0.05).The Bonferroni correction comparison showed a significant difference in the pitch of the front segment of the rising tone and the middle and last segment of the falling-rising tone in males,the middle segment of the rising and falling-rising tones in females between pairwise comparisons of the three groups(P’<0.0174).In general,the pitch abnormality of APS group was more obvious than that of PD group.3.In the assessment of vocal activity,the differences in VAI,FCR,VS A and DDKr values among the three groups were statistically significant(P<0.05).VAI values decreased sequentially in HC,PD and APS groups(P’<0.0174).FCR values differed between the APS and HC groups and between the PD and HC groups for males with significant(P’<0.0174).VSA values were significantly different between the PD and APS groups,the APS and HC groups(P’<0.0174),instead of the PD and APS groups(P’>0.0174).DDKr values decreased sequentially in HC,PD and APS groups(P’<0.0174).These indicates the facts that,compared with the PD group,the APS group was more restricted in the range of vowel articulatory activity,and that VAI and DDKr values are of higher discrimination sensitivity among the three groups.4.In terms of speech parameters,statistically significant differences were found when we compared the Jitter of/u/,/ü/and/o/between the PD and APS groups,as well as between the APS and HC groups(P’<0.017);the same in the pairwise comparisons of Shimmer of/o/and/e/,and HNR of/er/with Bonferroni correction(P’<0.017).The difference in sound intensity between the PD and APS groups was not significant(P’>0.017),meaning the sensitivity of sound intensity in discriminating between the two groups was low.5.Correlation analysis between differential acoustic parameters and clinical factors:VAI was weakly negatively correlated with VHI scores(r=-0.238);DDKr was weakly negatively correlated with UPDRS I(r=-0.291)and weakly positively correlated with MOCA scores(r=0.288);Shimmer scores for/o/were moderately positively correlated with UPDRSⅡ-Ⅲ scores,H-Y stages and VHI scores(r/o/=0.408,0.440,0.377,0.306),Shimmer scores for/e/were moderately positively correlated with UPDRS Ⅱ scores,UPDRS Ⅲ scores and H-Y stages(r/e/=0.363,0.342,0.324);HNR scores for/er/were moderately negatively correlated with UPDRS Ⅱ-Ⅲ scores,H-Y stages and VHI scores(r=-0.488,-0.492,-0.304,-0.448).6.Linear regression analysis of different acoustic parameters and clinical factors:There is a linear correlation between VAI values and VHI scores with the linear regression equation Y=1.020-0.007 VHI scores and fit effects(F=5.023 P=0.028 R2=0.057),between DDKr values and MOCA scores with the linear regression equation Y=1.761+0.158 MOCA scores and fit effects(F=40.985 P=0.000 R2=0.377),between Shimmer values of/o/and UPDRS Ⅲscores with the linear regression equation Y=1.661+0.034 UPDRS Ⅲ scores and fit effects(F=8.966 P=0.004 R2=0.108),between Shimmer values of/e/and H-Y stages with the linear regression equation Y=1.300+0.821 H-Y stages and fit effects(F=4.822 P=0.032 R2=0.055),and between HNR values of/er/and UPDRS Ⅱ scores with the linear regression equation Y=8.538-0.351 UPDRS Ⅱ scores and fit effects(F=21.613 P=0.000 R2=0.238).Conclusions1.Patients with early PD and APS shows abnormalities in vocal pitch variation,articulatory mobility and voice quality in different degrees compared to healthy individuals,and those with APS were even worse.Abnormal pitch elevation were found in the study in the front segment of the rising tone and the middle segment of the falling-rising tone of male PD and APS patients as well as in the rising tone and the middle and last segment of the falling-rising tone of female PD and APS patients.PD and APS patients had a restricted range of motion and voice disorders,but the intensity level was not significantly impaired.2.In this study,VAI,DDKr,Shimmer of/o/,/e/and HNR of/er/were found to be the differential acoustic parameters between early PD and APS.3.Although the changes in the differential acoustic parameters in PD and APS patients are to some extent influenced by clinical factors,their r and R2 values are comparatively low.Therefore,the above parameters are feasible to be regarded as the acoustic markers for early differentiation between PD and APS.