巴金森氏病患者言語障礙：音質、最長發音時長、S/Z比值、唇舌輪替動作音節速率、語速及清晰度

Abstract

With populations aging all over the world, Parkinson’s disease has become a noticeable health problem, and is expected to increase in the future. Parkinson’s disease (PD), termed as idiopathic parkinsonism, is a neurodegenerative disorder which mainly results from loss of dopaminergic neurons (Lang & Lozano, 1998a; Widnell, 2005; Li, Li, & Wang, 2009; Olanow, Stern, & Sethi, 2009; Patel et al., 2009). An estimated 70% of PD patients have speech or voice problems, characterized as hypokinetic dysarthria (Hartelius & Svensson, 1994; Goberman, Coelho, & Robb, 2002). Although previous studies have investigated the speech performances of PD patients, main of them focus only on voice quality in terms of several voice parameters and speaking rate by reading fixed passage. As a consequence, the goal of this present study is to assess speech deficits found in PD patients with dysarthria and investigates the correlation between speech deficits and disease severity, in terms of levodopa equivalent daily dose. This will be accomplished by focusing on six measures: (1) voice quality, (2) maximum sound prolongation (MSP), (3) S/Z ratio, (4) diadochokinetic (DDK) syllable rate, (5) speech intelligibility, and (6) speech rate. 16 male patients diagnosed with PD with Hoehn & Yahr Stage ratings of 2 to 4 were recruited from a hospital in Southern Taiwan. 16 control subjects, matched with age, sex and native language with the PD patients, also participated in this study. The present study has collected data by taking sound recordings of participants performing four oral tasks. Three major findings have been made: (1) PD patients tend to have speech deficits in the areas of MSP, DDK rate, speech intelligibility, and speech rate. PD patients are relatively unable to sustain certain sounds and have poor performance on oral cyclic movement. In addition, PD patients are less intelligible and speak much slower than controls in a variety of speech contexts. (2) When different speech contexts are compared, relatively low speech intelligibility in spontaneous monologue occurs, which may be due to the lack of the provision of external cues in conversation. (3) Disease severity, in terms of levodopa equivalent daily dose, is found to statistically correlate with speech rate of answering questions. Patients with more severe PD speak slower when people elicit new information from them, than those with less severe PD. These findings will help us to have a clearer understanding of the communication problems of patients with Parkinson’s disease, and it is hoped that this improved understanding will lead to more successful communication of PD sufferers with their family and caregivers.