Funding from The Parkinson Alliance helped to finance the following Parkinson’s research. Grantees were selected by scientific review committees of participating organizations. Updates will be posted, when available.
Project Title: The Effects of Directional STN-DBS on Speech and Gait in Parkinson’s Disease
Investigator/Author: Ritesh Ramdhani, MD
Objective: The goal of this study is to improve the clinical efficacy of Subthalamic (STN) Deep Brain Stimulation (DBS) in Parkinson’s patients by investigating the utility of directional stimulation via multiple independent current control technology in reducing the adverse effects on speech and improving the benefits on gait.
Methods/Design: We will assess recorded speech measures and gait kinematics using wearable sensors in subjects whose STN-DBS is changed from omnidirectional to directional stimulation. Parkinson’s specific metabolic brain network changes will then be explored using 18F-fluorodeoxyglucose (FDG) PET imaging of two DBS conditions in the dopaminergic OFF state: optimal directional DBS and omnidirectional stimulation. Lastly, probabilistic tractography measures will be derived from brain Magnetic Resonance Image (MRI) imaging to characterize white matter connections of the ipsilateral and contralateral subthalamic-striatal- cortical pathway between omnidirectional and directional stimulation
Relevance to Treatment of Parkinson’s Disease: High frequency, chronic stimulation of the subthalamic nuclei (STN) has become a widespread tool in the treatment of levodopa responsive Parkinson’s disease (PD)–minimizing tremor, motor fluctuations and dyskinesia. Like levodopa, however, deep brain stimulation (DBS) of the STN has had a less impressive impact on the axial symptoms, including balance, gait, and speech. Modifying DBS frequencies can be clinically useful for some patients, but this manipulation does not solve the potential adverse effects of DBS on speech and its minimal effects on gait problems. The present proposal is aimed at investigating the role of directional DBS in addressing these areas while broadening the understanding of directional stimulation both at a clinical and structure-functional network level.
Expected Outcome: We expect to find a differential speech and gait response with directional DBS and explore the structural-functional network changes associated with this response.