%0 Journal Article
%T Deep Brain Stimulation of Caudal Zona Incerta and Subthalamic Nucleus in Patients with Parkinson's Disease: Effects on Voice Intensity
%A Sofie Lundgren
%A Thomas Saeys
%A Fredrik Karlsson
%A Katarina Olofsson
%A Patric Blomstedt
%A Jan Linder
%A Erik Nordh
%A Hamayun Zafar
%A Jan van Doorn
%J Parkinson's Disease
%D 2011
%I Hindawi Publishing Corporation
%R 10.4061/2011/658956
%X Deep brain stimulation of the subthalamic nucleus (STN-DBS) in patients with Parkinson's disease (PD) affects speech inconsistently. Recently, stimulation of the caudal zona incerta (cZi-DBS) has shown superior motor outcomes for PD patients, but effects on speech have not been systematically investigated. The aim of this study was to compare the effects of cZi-DBS and STN-DBS on voice intensity in PD patients. Mean intensity during reading and intensity decay during rapid syllable repetition were measured for STN-DBS and cZi-DBS patients (eight patients per group), before- and 12 months after-surgery on- and off-stimulation. For mean intensity, there were small significant differences on- versus off-stimulation in each group: 74.2 (2.0)£¿dB contra 72.1 (2.2)£¿dB ( ) for STN-DBS, and 71.6 (4.1)£¿dB contra 72.8 (3.4)£¿dB ( ) for cZi-DBS, with significant interaction ( ). Intensity decay showed no significant changes. The subtle differences found for mean intensity suggest that STN-DBS and cZi-DBS may influence voice intensity differently. 1. Introduction Deep brain stimulation (DBS) in the subthalamic nucleus (STN) is an established and effective treatment for motor symptoms associated with Parkinson¡¯s disease (PD). Effects of STN-DBS on speech motor function, however, are less well defined and have been reported either as variable [1] or as an adverse side effect of the stimulation [2]. Recently, the caudal zona incerta (cZi) has been suggested as an alternative target in PD treatment [3, 4]. The effects of cZi-DBS on speech have not yet been reported in the literature. We have, therefore, decided to evaluate its effects on speech in conjunction with an on-going study on surgical outcomes of cZi-DBS, and to compare these with the effects of STN-DBS. Speech problems have been reported to occur in 70% [5] and 89% [6] of PD patients at some stage during the course of the disease, with higher prevalence as the disease advances in its severity and/or its time course [7]. The cardinal symptoms of speech dysfunction in PD (hypokinetic dysarthria) are weak voice, variable speech rate, short rushes of speech, imprecise consonants, breathy and harsh voice, and monotonous pitch. Of those symptoms, the perception of weak voice has been corroborated by acoustic measures of vocal intensity that demonstrate that PD patients have reduced intensity compared with healthy controls [8]. Reduced intensity is associated with the early stages of speech deterioration in PD and is often severely affected when profound speech problems exist [9]. Studies have shown that PD patients
%U http://www.hindawi.com/journals/pd/2011/658956/