%0 Journal Article
%T A Preliminary Report on Disordered Speech with Deep Brain Stimulation in Individuals with Parkinson's Disease
%A Christopher Dromey
%A Suzy Bjarnason
%J Parkinson's Disease
%D 2011
%I Hindawi Publishing Corporation
%R 10.4061/2011/796205
%X Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has proven effective in treating the major motor symptoms of advanced Parkinson's disease (PD). The aim of this study was to learn which laryngeal and articulatory acoustic features changed in patients who were reported to have worse speech with stimulation. Six volunteers with PD who had bilateral STN electrodes were recorded with DBS turned on or off. Perceptual ratings reflected poorer speech performance with DBS on. Acoustic measures of articulation (corner vowel formants, diphthong slopes, and a spirantization index) and phonation (perturbation, long-term average spectrum) as well as verbal fluency scores showed mixed results with DBS. Some speakers improved while others became worse on individual measures. The magnitude of DBS effects was not predictable based on the patients' demographic characteristics. Future research involving adjustments to stimulator settings or electrode placement may be beneficial in limiting the negative effects of DBS on speech. 1. Introduction A common sign of Parkinson¡¯s disease (PD) is hypokinetic dysarthria [1]. Typical speech characteristics include a weak, breathy voice, abnormal prosody, variability in rate, and imprecise movements of the articulators [2]. In addition, individuals with PD frequently have reduced facial animation and limited mobility of their oral musculature [3]. Prior to the 1960s, thalamotomy and pallidotomy surgeries were performed to treat symptoms of advanced PD, but reliance on these operations decreased dramatically when levodopa became widely available [4]. However, it subsequently became clear that levodopa, when used for an extended period of time, can cause problems of its own, such as drug-induced dystonia and dyskinesia [5]. Many patients also experience on-off effects, or periods when the motor benefits of levodopa are stable and then suddenly deteriorate [6]. A 1987 publication by a team in Grenoble sparked a renewed interest in surgical approaches to treating movement disorders [7], specifically through deep brain stimulation (DBS). In this procedure, which has evolved significantly since the early 1990s, electrodes are permanently implanted into the thalamus, globus pallidus, or subthalamic nucleus (STN) and the signals from an implanted pulse generator are used to influence neural activity in the basal ganglia circuitry and its output via the thalamus to the motor cortex. DBS is often preferred over tissue ablation procedures because negative side effects of DBS can be mitigated by adjusting the parameters of the
%U http://www.hindawi.com/journals/pd/2011/796205/