Investigating Adaptive Deep Brain Stimulation in Parkinson's Disease Management

INCLUSION CRITERIA A subject who meet all of the following criteria may be given consideration for inclusion in this clinical trial: * Is willing and capable of signing informed consent * Is ≥18 years old * Has been diagnosed with levodopa-responsive idiopathic Parkinson's disease * Has a Hoehn and Yahr (H\&Y) scale stage of II or III when OFF medication at screening * Exhibits motor fluctuations and PD-related symptoms that are not adequately controlled with medication, including motor complications of recent onset (\>4 months duration) * Has been referred for bilateral STN DBS in accordance with local practice * Must be a good surgical candidate for placement of a deep brain stimulator as judged by the DBS surgical team * Montreal Cognitive Assessment score of ≥ 26 at the screening visit (when in "medON" state) * UPDRS-III improvement by ≥30% with the levodopa challenge test as measured at approximately 90 minutes following administration of the challenge dose * Successfully completed a 1-day test diary reaching a sufficient level of agreement (\>75%) with study personnel responses and is willing and capable of completing a 5-day diary at each of the time points required per the protocol * If female, the subject is not currently pregnant (as determined by negative serum pregnancy test), breastfeeding, or is post-menopausal, surgically sterile or willing to use birth control for the duration of the study - acceptable forms of birth control are: hormone therapies (oral, injected, transdermal or implanted), IUD or other barrier methods (e.g., condom, diaphragm, cervical cap, spermicide/gel) or partner is surgically sterile * Is willing to maintain a constant anti-PD medication treatment (best medical management) for at least one month prior to DBS implantation * Is willing and able to attend all study-required visits, complete the study procedures and attend appropriate follow-up visits EXCLUSION CRITERIA * Has contraindications for DBS surgery, including any intracranial abnormality (e.g., generalized atrophy, vascular malformation, hydrocephalus, hematoma, cavernous or venous angioma, tumor or metastases, midline shift, etc.) or metallic implant (e.g., aneurysm clip, cochlear implant, etc.) or other clinically significant space-occupying lesion which in the opinion of the surgeon would impact the ability to target and place the leads or IPG * Is unable or unwilling to maintain a stable dose of levodopa anti-Parkinson's disease medication for 30 days prior to DBS surgery * Has any current major psychiatric disorder(s), such as Major Depressive Disorder, Bipolar I or II disorder, Schizophrenia, Schizoaffective Disorder, Delusional Disorder, Brief Psychotic Disorder, Obsessive-Compulsive Disorder, or any other current psychiatric condition that in the opinion of the investigator would confound the assessment of study endpoints, prevent proper data collection and/or compromise the subject's ability to participate, based on the psychiatric/psychological assessment at screening. It refers also to moderate or severe alcohol and/or substance use disorder based on the psychiatric/psychological assessment at screening. (It is permitted if a subject has a diagnosis of Major Depressive Disorder with symptoms that currently are well-controlled and managed by a stable regimen of antidepressants for a minimum of 4 weeks prior to the screening visit). * A history of suicide attempt within 3 years of the screening visit or current active suicidal ideation as determined by a psychiatric/ psychological evaluation * Any medical condition, such as cognitive impairment, dementia, seizures, congestive heart failure, unstable angina, uncontrolled diabetes, renal failure requiring dialysis, or any other severe medical condition that could interfere with study procedures, confound the assessment of study endpoints, prevent proper data collection, or that, in the opinion of the investigator, would compromise the subject's ability to participate * Confirmation of diagnosis of a terminal illness associated with survival \<12 months * Needs repeated MRI scans * Requires diathermy, transcranial magnetic stimulation (TMS), or electroconvulsive therapy (ECT) * Has an electrical or electromagnetic implant (e.g., cochlear prosthesis, pacemaker, neurostimulator, etc.) or plans to obtain, an active implanted medical device (AIMD) and/or an implanted medication pump (e.g., DUOPA™ infusion pump) and/or is treated with a portable infusion pump for any indication * Is on anticoagulant therapy which cannot be paused for \>5 days before surgery * A history of cranial surgery including ablation procedure or any other previous neurosurgical procedure for the treatment of PD symptoms on either side of the brain * Is currently participating in another clinical study (excluding any sub-study of the present trial).