Scalar Closed Loop Intraoperative Study

The purpose of this study is to measure neural activity during deep brain stimulation (DBS). There are two types of neural activity that we will record from DBS electrodes during this study: DBS local evoked potentials (DLEPs) and spontaneous, local field potentials (LFPs). We will measure the effects of varying stimulation parameters on both the neural activity and changes in motor symptoms -- bradykinesia and tremor -- in subjects with Parkinson's disease (PD). Correlating neural activity characteristics with changes in symptoms will improve our understanding of the mechanisms of action of DBS. This intraoperative study will specifically compare our ability to record neural activity using circuitry developed at Duke for this purpose \[Kent et al, 2015\] to a new, implanted pulse generator (IPG; RC+S) developed by Medtronic. These intraoperative studies will specifically test a preliminary version of the RC+S (that is not designed for implantation), and will lead to a clinical trial assessing the efficacy of the implantable RC+S IPG in PD patients once this device is available and approved for this trial.