Speech Deficits in Patients with Parkinson's Disease: Voice Quality Maximum Sound Prolongation S/Z Ratio Diadochokinetic Syllable Rate Speech Rate and Speech Intelligibility

  • 方 岑

Student thesis: Master's Thesis


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
Date of Award2014 Jul 30
Original languageEnglish
SupervisorLi-Mei Chen (Supervisor)

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