Neural Signatures of Parkinson's Disease

Study Overview
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Brief Summary
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The purpose of this study is to provide objective measurements of abnormal movements of the body in correlation with neural activity of the brain and track how these change over time. This may allow for the development of objective evaluation of the neural activity causing abnormal movements, which may lead to the ability of the DBS system to stimulate the brain by sensing the abnormal neural activity that is causing abnormal movements.

Official Title
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Neural Signatures of Tremor, Bradykinesia and Freezing in the Subthalamic Region on Parkinson's Disease and Their Acute and Long-Term Modulation by Subthalamic Deep Brain Stimulation.

Conditions
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Parkinson's Disease

Intervention / Treatment
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* Device: Activa PC+S


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: a diagnosis of idiopathic Parkinson's disease, with bilateral symptoms at Hoehn and Yahr Stage greater than or equal to II. Documented improvement in motor signs on versus off dopaminergic medication, with a change in the Unified Parkinson's Disease Rating Scale motor (UPDRS III) score of >= 30% off to on medication. The presence of complications of medication such as wearing off signs, fluctuating responses and/or dyskinesias, and/or medication refractory tremor, and/or impairment in the quality of life on or off medication due to these factors. Subjects should be on stable doses of medications, which should remain unchanged until the DBS system is activated. After the DBS system is optimized (during which time the overall medication dose may be reduced to avoid discomfort and complications such as dyskinesias) the medication dose should remain unchanged, if possible, for the duration of the study. Treatment with carbidopa/levodopa, and with a dopamine agonist at the maximal tolerated doses as determined by a movement disorders neurologist. Ability and willingness to return for study visits, at the initial programming and after three, six and twelve months of DBS. Age > 18 Exclusion Criteria: Subjects with significant cognitive impairment and/or dementia as determined by a standardized neuropsychological battery. Subjects with clinically active depression, defined according to the Diagnostic and Statistical manual of Mental Disorders, Fourth Edition (DSM-IV) criteria and as scored on a validated depression assessment scale. Subjects with very advanced Parkinson's disease, Hoehn and Yahr stage 5 on medication (non-ambulatory). Age > 80. Subjects with an implanted electronic device such as a neurostimulator, cardiac pacemaker/defibrillator or medication pump. Subjects, who are pregnant, are capable of becoming pregnant, or who are breast feeding. Patients with cortical atrophy out of proportion to age or focal brain lesions that could indicate a non-idiopathic movement disorder as determined by MRI Subjects having a major comorbidity increasing the risk of surgery (prior stroke, severe hypertension, severe diabetes, or need for chronic anticoagulation other than aspirin). Subjects having any prior intracranial surgery. Subjects with a history of seizures. Subjects, who are immunocompromised. Subjects with an active infection. Subjects, who require diathermy, electroconvulsive therapy (ECT), or transcranial magnetic stimulation (TMS) to treat a chronic condition. Subjects, who have an inability to comply with study follow-up visits. Subjects, who are unable to understand or sign the informed consent

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Activa PC+S<br> | Device: Activa PC+S<br>* The Model 37604 Activa PC+S is a multiprogrammable device that can deliver therapeutic electrical stimulation and record bioelectric signals from leads implanted in the brain.<br>* Other names: Model 37604;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Resting State Beta Band Power Over Time | We compared the beta band (13-30 Hz) power in the neural signal at the initial programming visit (baseline) and at the 12 month follow-up visit (1 year) after turning off deep brain stimulation therapy. Beta band power is normalized to average beta band power at the initial programming visit. Using a linear mixed model for repeated measures over time, regression beta coefficient was obtained to determine if beta power changed significantly between the initial programming and the 12 month follow-up visit. | Baseline and 1 Year | 
| Sample Beta Entropy | Sample entropy is a measure of estimated conditional predictability, calculated within a frequency range of a patient's local field potential. Freezers are subjects who have clinical history of freezing of gait symptoms and/or if the subject displayed freezing behavior pre-operatively or during the in-study gait tasks relative to non-freezers, those who have never experienced freezing of gait. We measured sample beta (13-30 Hz) entropy in subjects' local field potential. Higher values of sample entropy indicate lower estimated conditional predictability. Testing occurred over one day, at a range of approximately 1 month to 7 months post DBS device implantation. | 1 day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Parkinson's Disease, DBS, Deep Brain Stimulation, Subthalamic Nucleus