Udall Project 2 Aim 2A&C

Study Overview
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Brief Summary
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This protocol will leverage the novel (on-label, FDA-approved) local field potential measuring capability of the Medtronic Percept™ PC DBS system to study the effects of globus pallidus internus and globus pallidus externus (GPi, GPe) DBS on: the wash-out and wash-in dynamics of motor behavior and local field potentials (LFPs) and correlations between fluctuations in gait and LFPs during activities of daily living (recorded over 4 weeks). These experiments will elucidate the relationships between GP LFPs oscillations, lower limb function, postural control and gait performance.

Detailed Description
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This protocol will leverage the novel (on-label, FDA-approved) local field potential measuring capability of the Medtronic Percept™ PC DBS system to study the effects of globus pallidus internus and globus pallidus externus (GPi, GPe) DBS on: the wash-out and wash-in dynamics of motor behavior and local field potentials (LFPs) and correlations between fluctuations in gait and LFPs during activities of daily living (recorded over 4 weeks). These experiments will elucidate the relationships between GP LFPs oscillations, lower limb function, postural control and gait performance.

Official Title
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Mechanisms and Effects of Pallidal Deep Brain Stimulation on Levodopa Resistant Motor Signs in Parkinson's Disease; Udall Project 2 Aim 2A&C

Conditions
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Parkinson Disease

Intervention / Treatment
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* Other: observational-- no intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Receiving DBS therapy in GP for treatment of PD Implanted with Medtronic Percept DBS system At least 3 months since initial activation of the neurostimulator Exclusion Criteria: history of musculoskeletal disorders that significantly affects the ability to perform the motor tasks in the specific experiment in question history of dementia or cognitive impairment other significant neurological disorder as determined by the PI post-operative complications or adverse effects (e.g. ON stimulation dystonias) that affect patient safety or confound the experiment lack of capacity to consent (as identified by UBACC)
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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Participants<br>Inclusion criteria for all aims/experiments Receiving DBS therapy in GP for treatment of PD Implanted with Medtronic Percept DBS system At least 3 months since initial activation of the neurostimulator | Other: observational-- no intervention<br>* observational<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak negative power | A servo-controlled ankle manipulandum will be used to obtain objective measures of resistance about the dorsiflexion/plantar flexion axis (range of motion approximately 5 deg. dorsiflexion to 30 deg. plantar flexion; frequency = 1.5 Hz). Two conditions will be tested: passive movement with and without an activation maneuver on the contralateral side (repetitive tapping of the toe or heel). | 30 day | 
| Stride length | The spatial and temporal parameters of overground steady-state gait will be assessed in the lab or derived from the wearable device (mPower) | 30 days | 
| Alpha power during standardized daily gait assessment | The participant will use their DBS device patient programmer to record a time stamp and capture LFPs using the implanted Medtronic Percept™ device during the standardized daily gait assessments. | 30 days | 
| cadence | The spatial and temporal parameters of overground steady-state gait will be assessed in the lab or derived from the wearable device (mPower) | 30 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| gait speed | The spatial and temporal parameters of steady-state gait will be assessed using a computerized walkway. | 30 days | 
| time spent away from home | time spent away from home, as measured by the mPower smartphone app | 30 days | 
| distance traveled from home | distance traveled away from home, as measured by the mPower smartphone app | 30 days | 
| alpha power immediately following freezing of gait episodes, falls and other major events | The participant will use their DBS device patent programmer to record a time stamp when they experience a freezing of gait episode and LFPs will be recorded immediately following that time by the implanted Medtronic Percept™ device | 30 days | 
| Peak power of local field potential oscillations | average daytime peak alpha and beta power derived from power spectral density analysis of the local field potential signal recorded by the implanted Medtronic Percept™ device | 30 days | 
| stride time variability | The spatial and temporal parameters of steady-state gait will be assessed using a computerized walkway. | 30 days | 
| step length variability | The spatial and temporal parameters of steady-state gait will be assessed using a computerized walkway. | 30 days |