%0 Journal Article %T Progression of Voice and Speech Impairment in the Course of Parkinson's Disease: A Longitudinal Study %A S. Skodda %A W. Gr£¿nheit %A N. Mancinelli %A U. Schlegel %J Parkinson's Disease %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/389195 %X Impairment of voice and speech occurs in the majority of patients in the course of Parkinson's disease (PD). The aim of the current study was to survey the changes of voice and speech performance in the individual patients over time. 80 patients with PD and 60 healthy speakers were tested and retested after at least 12 months (average time interval: 32.5 months). Participants had to read a given text which was digitally recorded as a source for the perceptual and acoustic analysis. Stage of the disease and global motor impairment were rated according to the accepted scales. As a result, abnormalities of voice and speech were already present in mildly affected patients and there were significant deteriorations of quality of voice and articulatory velocity and precision between baseline and followup examination which showed no correlation with the time interval between the visits. Summarized, voice, and speech performance were found to further deteriorate in the individual patient in the course of time although global motor impairment was widely stable which might be a hint for nondopaminergic mechanisms of progression of dysarthrophonia. Further investigations are warranted to get a better insight into the dynamics of the progression of voice and speech impairment in PD as a precondition for the development of therapeutic approaches. 1. Introduction Voice and speech impairment (also called ¡°dysarthrophonia¡±) is a typical symptom of Parkinson¡¯s disease (PD) and occurs in the majority of patients in the course of the illness [1¨C3]. The progressive loss of the ability to communicate is considered to be an important source of disability in patients with PD [3¨C6]. The typical pattern of hypokinetic dysarthria is characterized by a breathy or hoarse voice, reduced loudness and restricted pitch variability (monopitch and monoloudness), imprecise articulation and abnormalities of speech rate, and pause ratio (e.g., [7¨C9]). These multidimensional abnormalities of voice and speech have traditionally been attributed to the dopaminergic deficit manifesting in hypokinesia and rigidity of the laryngeal muscles [10, 11]. Indeed, there is some evidence for an amelioration of at least some single speech dimensions such as pitch and loudness variability under dopaminergic treatment (e.g., [12, 13]). However, other studies have failed to demonstrate a clear causal relationship between dopaminergic dysfunction and overall speech performance (e.g., [14]); therefore, it had been suggested that alterations of voice and speech in PD might be at least partly due to %U http://www.hindawi.com/journals/pd/2013/389195/