Motor Network Physiology

Study Overview
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Brief Summary
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The brain networks controlling movement are complex, involving multiple areas of the brain. Some neurological disorders, like Parkinson's disease (PD) and essential tremor (ET), cause abnormalities in these brain networks. Deep brain stimulation is a treatment that is used to treat these types of neurological diseases and is thought to help patients by modulating brain networks responsible for movement. Levodopa medication is also used to modulate this brain networks in patients with PD. The overall objective is to develop a unified theory of basal ganglia thalamocortical (BGTC) circuit dynamics that accounts for disease symptomatology, movement, and their inter-relationship. The underlying hypothesis, is that the rigidity and bradykinesia of PD are fundamentally related to excessive functional coupling across nodes in the BGTC motor circuit impeding effective information flow. In this research, the investigator will take advantage of the unique opportunity provided by awake deep brain stimulation surgery to learn more about how the brain functions in a diseased state and how deep brain stimulation changes these networks to make movement more normal. The investigator will simultaneously assess cortical and subcortical electrophysiology in relation to clinical symptoms and behavioral measures and in response to deep brain stimulation, cortical stimulation, and pharmacologic therapy in patients undergoing Deep Brain Stimulation (DBS) implantation surgery.

Official Title
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Motor Network Physiology Characterization During Deep Brain Stimulation Surgery

Conditions
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Parkinson Disease, Essential Tremor

Intervention / Treatment
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* Drug: Inbrija
* Other: Subcortical Stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of Parkinson's disease or Essential Tremor who have been recommended to undergo deep brain stimulation for management of their movement disorder Preoperative MRI without evidence of cortical or subdural adhesions or vascular abnormalities Willingness and ability to cooperate during conscious operative procedure for up to 40 minutes Exclusion Criteria: Patients with recent use (within one week) of anticoagulant or antiplatelet agents Neurocognitive testing indicating amnestic cognitive deficits

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 89 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Parkinson's disease patients<br>This group consists of Parkinson's disease patients who are undergoing deep brain stimulation surgery for treatment of their movement disorder. Participants will complete behavioral assessments while receiving subcortical DBS stimulation and / or inhaled levodopa medication, Inbrija. Stimulation will be applied at the previously determined therapeutic frequency. Two capsules (84 mg) of Inbrija will be administered. | Drug: Inbrija<br>* Inbrija will be administered to Parkinson's disease patients only. Patients will receive 2 capsules (84 mg) of medication.<br>Other: Subcortical Stimulation<br>* Subcortical simulation of the deep brain stimulation surgery target site will be applied by clinically placed deep brain stimulation electrodes at the previously determined therapeutic setting<br>|
| Essential Tremor patients<br>This group consists of essential tremor patients who are undergoing deep brain stimulation for treatment of their movement disorder. Participants will complete behavioral assessments while receiving subcortical DBS stimulation. Stimulation will be applied at the previously determined therapeutic frequency. | Other: Subcortical Stimulation<br>* Subcortical simulation of the deep brain stimulation surgery target site will be applied by clinically placed deep brain stimulation electrodes at the previously determined therapeutic setting<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| cortical ECoG and subcortical recordings | Cortical ECoG and subcortical LFP recordings will occur during DBS implantation surgery during the behavioral assessments and/or Inbrija administration. | baseline | 
| Behavioral assessment | Each patient will complete a task that assesses the kinematics of movement, self-initiation of movement, and/or effect of Inbrija on movement | baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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deep brain stimulation, levodopa medication, motor cortex, basal ganglia, thalamus