[Bradykinetic utterances and monopitch speech in patients with Parkinson's disease]

We compared vocalization and speech of 20 patients with Parkinson's disease with those of 24 healthy volunteers using acoustic analysis. The time from the beginning of pronunciation of "a" to the maximum amplitude was significantly longer in the Parkinson group than in the healthy group. In a reading aloud test using a short sentence "o-te-ra-ni-o-ba-ke-ga-de-ta (a ghost appeared in a temple)", the coefficient of variation of the mean fundamental frequency for each syllable was significantly smaller in the Parkinson group. In addition, the Parkinson group showed few changes in the fundamental frequency of the each syllable through the whole sentence, which was spoken in a monopitch pattern. However, there were no differences between the Parkinson group and the healthy volunteers in the time that each syllable was sustained and in the length of syllables. These results suggest that patients with Parkinson's disease have bradykinetic utterance. In reading aloud the short sentence, the tone of each syllable was flat and the speech was monopitch lack articulation. The saccadic eye movements of 15 of the patients with Parkinson's disease were recorded using an electrooculogram in order to evaluate the correlation with bradykinetic utterances. Although monopitch speech and bradykinetic utterances were correlated, the bradykinetic saccadic eye movements and bradykinetic utterances were not correlated.