Study of Motor Control Mechanisms in DBS-implanted Parkinson's Disease Patients

Study Overview
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Brief Summary
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Akinesia is one of the most prominent symptom in Parkinson's Disease (PD) patients. It typically consists in a inability to initiate voluntary movement, and it affects patients' quality of life. This study aims at exploring the influence of Deep Brain Stimulation (DBS) in the quality of motor control, and particularly of voluntary movement initiation, and its neural correlates. They will be evaluated using behavioral and motor tasks together with Transcranial Magnetic Stimulation (TMS) and electrophysiology (EMG and EEG).

Official Title
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Study of Motor Control Mechanisms in DBS-implanted Parkinson's Disease Patients

Conditions
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Parkinson Disease

Intervention / Treatment
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* Device: transcranial magnetic stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: PD patients that are monitored for the tuning of their DBS stimulator by Grenoble's Hospital. PD patients that are hospitalized for the tuning routine 12 months after the surgical implantation. Good tolerance following temporary stops of the DBS stimulator Affiliated to a social security system Mental abilities sufficient for performing the behavioral tasks (MMSE score >= 24, tested less than 6 months ago) Exclusion Criteria: Patients that are concerned by articles L1121-5, L1121-6, L1121-7 and L1121-8 of French Code de la Santé Publique, History of psychiatric or neurological illness other than PD Patients that are currently excluded from an other clinical trial Contraindications for TMS practice Inability to stay seated without pain for two hours Pregnancy

Ages Eligible for Study
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Minimum Age: 30 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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Deep brain stimulation ON<br>Patients will undergo every experimental tasks with their DBS stimulator in ON and OFF positions. Order of ON/OFF conditions will be counterbalanced between patients. | Device: transcranial magnetic stimulation<br>* TMS will be delivered on the sensory-motor system and the inhibitory motor control network while patients are performing behavioral and motor tasks. Brain and muscle activity will be recorded concurrently using EEG and EMG respectively.<br>* Other names: electromyography;|
| Placebo Comparator: Deep brain stimulation OFF<br>Patients will undergo every experimental tasks with their DBS stimulator in ON and OFF positions. Order of ON/OFF conditions will be counterbalanced between patients. | Device: transcranial magnetic stimulation<br>* TMS will be delivered on the sensory-motor system and the inhibitory motor control network while patients are performing behavioral and motor tasks. Brain and muscle activity will be recorded concurrently using EEG and EMG respectively.<br>* Other names: electromyography;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Corticospinal excitability | Corticospinal excitability is measured trough the amplitudes of TMS-evoked motor potentials recorded on the EMG at rest, and during the behavioral and motor tasks, in the two experimental conditions (DBS stimulator ON and OFF). | 60 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cortical excitability | Cortical excitability is measured trough the amplitudes of TMS-evoked potentials recorded on the EEG at rest, in the two experimental conditions (DBS stimulator ON and OFF). | 60 minutes | 
| Cortico-subcortical connectivity | Cortico-subcortical connectivity will be assessed on EEG signal using paired stimulation between TMS and DBS. | 20 minutes | 
| Correlation between behavioral and neural responses | Behavioral outcomes (such as reaction time, performance index, etc.) will be compared with neural correlates described in outcomes 1 and 2 and 3. | 60 minutes |