Deep Brain Stimulation Neural Recordings of Varied Stimulation During Sleep in Parkinson's Disease

Inclusion Criteria:

* Male or female \> 18 years of age
* Diagnosed with idiopathic Parkinson Disease
* Have bilateral implantation of Medtronic's PerceptTM PC (Medtronic Neurological Division, Minneapolis, MN, USA) Deep Brain Stimulation (DBS) system targeting the subthalamic nucleus (STN) and have had their stimulation settings optimized for a minimum of three months
* Report a response score of one or greater on question 1.7 of the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part I;
* Demonstrate ability to ambulate independently;
* Be capable of providing informed consent;
* If taking sleep-supporting medications, dosing must be stable for at least 30 days

Exclusion Criteria:

* Presence of neurological diseases other than Parkinson Disease, such as stroke or multiple sclerosis
* Active sleep disorders, including narcolepsy, moderate to severe (Apnea-Hypopnea Index\>=15) untreated sleep apnea, uncontrolled restless legs syndrome
* Cognitive impairment meeting the criteria for dementia as per the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV), based on formal neuropsychological evaluation
* Ongoing alcohol or substance abuse; Working night shifts or irregular work hours

The main concern for vulnerable subjects will be for the possibility of reduced decision-making capacity. For this we intend to exclude individuals who have a diagnosis of dementia.