Ontmoetingen met Koen Raes

Book with contributions on writings and ideas of Koen Raes

The influence of subthalamic nucleus stimulation on pragmatic language production in Parkinson’s disease

While the influence of deep brain stimulation (DBS) of the subthalamic nucleus (STN) on the comprehension of pragmatic language in Parkinson's disease (PD) has been the focus of studies, its impact on production, however, has yet to be elucidated. (1) Investigating the inf luence of DBS STN on pragmatic language production in spontaneous speech by comparing different stimulation conditions and (2) evaluating the effect of asymmetric dopaminergic denervation. This paper included 18 patients with advanced idiopathic PD with STN DBS. [Ten PD patients with predominantly left hemispheric dopamine denervation (PD-left) and eight PD patients with predominantly right-hemispheric dopamine denervation (PD-right).] The pragmatic components 'communicative functions' and 'conversational skills' were evaluated by analysing the spontaneous language production in four stimulation conditions. STN stimulation did not appear to influence the pragmatic production skills. Only when asymmetric dopamine depletion was taken into account the parameter 'giving an explanation' interaction was detectable. STN DBS appears to have some influence on the production of pragmatic language depending on asymmetric dopaminergic denervation. Suggestions are made for further research of pragmatic production in Parkinson's disease

The relationship between speech production and speech perception deficits in Parkinson's disease

Purpose: This study investigated the possible relationship between hypokinetic speech production and speech intensity perception in patients with Parkinson’s disease (PD). Method: Participants included 14 patients with idiopathic PD and 14 matched healthy controls (HCs) with normal hearing and cognition. First, speech production was objectified through a standardized speech intelligibility assessment, acoustic analysis, and speech intensity measurements. Second, an overall estimation task and an intensity estimation task were addressed to evaluate overall speech perception and speech intensity perception, respectively. Finally, correlation analysis was performed between the speech characteristics of the overall estimation task and the corresponding acoustic analysis. The interaction between speech production and speech intensity perception was investigated by an intensity imitation task. Results: Acoustic analysis and speech intensity measurements demonstrated significant differences in speech production between patients with PD and HCs. A different pattern in the auditory perception of speech and speech intensity was found in the PD group. Conclusions: Auditory perceptual deficits may influence speech production in patients with PD. The present results suggest a disturbed auditory perception related to an automatic monitoring deficit in PD

Speech production and speech perception deficits in Parkinson's disease: are they related?

Background - Hypokinetic dysarthria in patients with idiopathic Parkinson’s disease (PD) has been traditionally attributed to classic signs of the disease, namely muscle rigidity and bradykinesia. To date, research recognizes a broader alternative view in which hypokinetic dysarthria is considered to be more than a pure production deficit. This study aimed to examine a possible relationship between hypokinetic speech production and speech intensity perception in PD. Methods - Subjects included 14 patients with idiopathic PD and 14 one-to-one matched healthy control speakers (HC) with normal hearing and cognition. First, speech production was objectified through a standardized and norm-referenced speech intelligibility assessment at sentence level (DIA-S) and through acoustic analysis (F0 variability, amplitude variability, F2 transition, VSA, spectral centroid, speech diadochokinetic rate, jitter, shimmer, and MPT). Correlations between acoustic analysis and speech intelligibility were computed. Speech intensity was examined based on different tasks (spontaneous speech, reading and sustained phonation). Second, overall speech perception was determined by an overall estimation task, performed in two different conditions (immediate versus playback perception) based on two different tasks (spontaneous speech and reading). An intensity estimation task was addressed to evaluate speech intensity perception. Finally, the interaction between speech production and speech intensity perception was investigated by an intensity imitation task. Results - Concerning speech production, F0 variability and MPT were significantly decreased in patients with PD. Significant positive correlations were found between F0 variability, F2 transition, spectral centroid, and speech intelligibility. Speech intensity seemed to be task dependent. Concerning speech perception, significant differences between the different conditions and tasks in the overall estimation task were only found in the PD group. These results emphasize the discrepancy between spontaneous speech and cued regulation (e.g. non-propositional speech, auditory feedback) in patients with PD and point at the role of attention and feedback processes in the auditory perception of speech in PD. Despite the low cognitive load of the intensity estimation and imitation task, a different pattern in the auditory perception of speech intensity could be demonstrated in the PD group. Conclusions - Auditory perceptual deficits may influence speech production in patients with PD. The present results suggest a disturbed auditory perception related to an automatic monitoring deficit in PD