Deep Brain Stimulation of the nbM to Treat Mild Cognitive Impairment in Parkinson's Disease

The purpose of this study is to evaluate the safety and effectiveness of deep brain stimulation of the nucleus basalis of Meynert (also called the "nbM") at improving memory in Parkinson's disease patients with mild cognitive impairments and memory difficulties. Patients with Parkinson's disease (PD) that are eligible for Deep Brain Stimulation (DBS) therapy for improvement of their motor symptoms and with evidence of mild cognitive impairments and memory difficulties will be enrolled.

This is a prospective, double-blind (patient and neuropsychologist), randomized, cross-over study to evaluate the safety of deep brain stimulation of the nucleus basalis of Meynert (nbM) in Parkinson's disease (PD) patients with mild cognitive impairment (PD-MCI) who are undergoing globus pallidus internus (GPi) stimulation for their motor symptoms. Six patients with PD who are eligible for GPi DBS for improvement of their motor symptoms and who have a clinical diagnosis of PD-MCI (amnestic, single or multiple domain) per Movement Disorder Society (MDS) criteria will be enrolled and implanted with bilateral electrodes in in the nbM in addition to the globus pallidus internus (GPi). Conventional stereotactic implantation of the electrodes will be guided by intraoperative computerized tomography (CT) and magnetic resonance tomography (MRT).

Eligibility Criteria:
Inclusion Criteria:

* Informed consent signed by the subject.
* Parkinson's disease per UK Parkinson's Disease Society Brain Bank (Queens Square) criteria
* Diagnosis of PD-MCI, amnestic subtype per MDS criteria (Level II assessment)
* DBS candidate for GPi targeting per the consensus committee
* 50 - 75 years of age
* Primary English speaking
* Minimum of 10 years of education
* Motorically and cognitively capable of completing evaluations and consent
* Medically cleared for surgery and anesthesia
* Subject must be on stable doses of any medication used to treat PD or cognition for 3 months prior to study entry
* Female subjects with child-bearing potential have a negative serum pregnancy test prior to DBS surgery -

Exclusion Criteria:

* Dementia per DSM-V criteria
* Condition precluding MRI
* History of supraspinal CNS disease other than PD
* Medical condition or required medication compromising cognition
* Alcohol use of more than 4 drinks per day
* Currently uncontrolled moderate-severe depression (BDI\>20)
* History of suicide attempt in the year preceding study screening
* History of schizophrenia, delusions, or currently uncontrolled visual hallucinations
* Use of cholinesterase inhibitor
* Subjects who require rTMS, ECT, diathermy, or repeat MRI procedures to treat a medical condition.
* Subjects with a history of seizure disorder
* Subjects who have made a suicide attempt within the prior year,
* Subjects with any medical contraindications to undergoing DBS surgery (eg, infection, coagulopathy, or significant cardiac or other medical risk factors for surgery)
* Subjects with an implanted stimulator such as a cardiac pacemaker, defibrillator, neurostimulator and cochlear implant
* Subjects who are pregnant or nursing.