Subthalamic Nucleus Deep Brain Stimulation in Speech Study

Study Overview
=================
Brief Summary
-----------------
Parkinson's disease (PD) patients treated with deep brain stimulation (DBS) of the subthalamic nucleus (STN) have unpredictable and varied speech outcomes after this treatment. Our research will prospectively document speech performance before, during and 6- and 12-months after STN-DBS in 80 surgically treated patients and compared with 40 non-surgical controls with Parkinson's disease. This study will provide unique insights into the role of STN in speech production, document speech outcome in a comprehensive fashion, identify factors that predict functional communication ability 12 months after STN-DBS, and test the feasibility of low frequency DBS in reversing DBS-induced speech declines in order to optimize treatment strategies for those living with Parkinson's disease.

Detailed Description
-----------------
Aim 1. Define the mechanistic role of STN in speech using direct intraoperative brain recordings. For the first time, we will define STN neuronal physiology for both speech and limb tasks. Through multichannel microelectrode recording (MER) during awake STN-DBS implantation surgery, we will test the hypothesis suggested by our pilot data that STN firing rate during speech will be significantly different from the firing rate during a limb motor task. Aim 2. Advance understanding of speech outcomes associated with STN-DBS. Intelligibility will serve as the primary functional communication outcome, with communication participation as a secondary metric. Acoustic measures of articulation, phonatory-respiratory behavior and tempo-fluency will be obtained. Aim 2A. Determine differential effects of DBS stimulation (ON vs. OFF) on speech outcomes. ON vs. OFF stimulation changes in acoustic measures of speech will be used to inform potential reasons for observed changes in intelligibility. Aim 2B. Define longitudinal effects of STN-DBS on speech outcomes. Speech outcomes and limb measures obtained pre-surgery will be compared to those at 6 and 12 months post-surgery when DBS stimulation is ON. Change in communication participation also will be defined. The control group studied at similar time points will control for disease progression. Aim 2C. Determine associations between acoustic measures and intelligibility in STN-DBS. Aim 3. Explore factors associated with changes in intelligibility post STN-DBS. As initial endeavors to guide future studies, we will: Aim 3A. Use our metrics from Aims 1 and 2 (e.g. disease-specific characteristics, microelectrode recording data, pre-operative intelligibility) to identify factors that predict intelligibility at 12 months following STN-DBS. Aim 3B. Test the feasibility of manipulating DBS stimulation parameters to improve intelligibility in a subset of participants with DBS-induced intelligibility declines.

Official Title
-----------------
Role of Subthalamic Nucleus in Speech and Movement Among People With Parkinson's Disease as Revealed by Intraoperative Recordings and Deep Brain Stimulation

Conditions
-----------------
Parkinson Disease, Dysarthria

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: For inclusion in this study, participants must have a confirmed diagnosis of idiopathic Parkinson's disease and no atypical Parkinsonism features experience significant motor fluctuations currently taking and responsive to dopaminergic medications (e.g. Levodopa) use English as their primary language lack significant cognitive impairment and be able to consent to participate Exclusion Criteria: Significant hearing loss/reliance on hearing aids

Ages Eligible for Study
-----------------
Minimum Age: 21 Years
Maximum Age: 84 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| DBS-STN<br>The DBS-STN group will consist of individuals with Parkinson's disease who have already elected to undergo deep brain stimulation surgery. | |
| Control<br>The control group will consist of individuals with Parkinson's disease who are not undergoing deep brain stimulation placement. No interventions will be completed with the control group. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neuron Firing Rate | DBS-STN participants will complete simple speech and motor tasks during surgery while the surgeon records neuron firing rate using Microelectrode Recording (MER). | Intraoperatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Speech Intelligibility with DBS ON | Speech intelligibility will be measured using the Sentence Intelligibility Test (SIT). Speech intelligibility ratings are measured as percentages, with lower percentages indicating more severe speech impairments. | Speech intelligibility with DBS ON will be measured at the 6 month follow up and 12 month follow up for the DBS-STN group. | 
| Speech Intelligibility (stimulation OFF or not applicable) | Speech intelligibility will be measured using the Sentence Intelligibility Test (SIT). Speech intelligibility ratings are measured as percentages, with lower percentages indicating more severe speech impairments. | Speech intelligibility without stimulation will be measured at baseline, 6 month, and 12 month visits for all participants. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Deep Brain Stimulation, Parkinson, Speech, Movement, Intelligibility