Organização Temporal na Fala Disártrica: comparação entre populações com distúrbios nos núcleos da base

Abstract

The neural networks that encompass the basal ganglia (subcortical structure in the human CNS) participate in the control of the body voluntary movements, including those of speech. Therefore, diseases that affect basal ganglia function like Parkinson.s disease (ParkD), Huntington.s disease (HD) and Sydenham chorea (SC) may generate abnormal hypokinetic or hyperkinetic movements, which may consequently influence the motor control of speech.The aim of this study was to understand how the prosodic temporal organization varies among subjects with hypokinetic and hyperkinetic dysarthria in ParkD, in HD, and in SC.We evaluated fifteen subjects with ParkD (with and without medication ON and OFF), fifteen with HD, fifteen with SC, and eighteen in the control group. All the subjects recorded the same text so that it was possible to study the temporal organization with the waveform and the spectrogram. The identification and marking of the pause (according to the syntactic boundaries) were manually made separating the recordings in pauses and articulated sequences. Measures were: total speech time (which is the total speaking time plus the total time of silent pauses), the number of pauses and their average duration, speech rate (number of syllables divided by total speech time), speaking rate (number of syllables divided by total speaking time), total fluency time, and total disfluency time. In the statistical analysis, besides descriptive data, variance analysis (ANOVA), the Bonferoni method of multiple comparisons, the Pearson Correlation Coefficient, the Bootstrap method, and Student.s t-test were used.Our results show that there is a great variability in the group with ParkD, whose patients presented a higher average duration of pauses compared to the control group. ParkD.s speech and speaking rates are a little lower than those of the control group. The HD group also presents slowness in the temporal parameters and so do the subjects with SC, but in a lower degree. All groups preserved the syntactic function of prosody, but in different levels. Regarding to global motor impairment in ascending order are the groups SC, HD, ParkD ON and ParkD OFF. However, there was no correlation between global motor scales and speech temporal parameters. There are variable correlations between the syntactic boundaries and the duration of the pauses in all groups.As a conclusion, we state that the subjects with ParkD, HD and SC show slowness in speech production, maintenance of prosody syntactic function in different levels, and they cannot be differentiated according to the temporal organization of speech neither among themselves nor in comparison to the control group. It seems that basal ganglia disfunction equally affects all clinical groups despite of ethiology.