The Effect of Low Frequency STN DBS on Sleep and Vigilance in Parkinson's Disease (PD) Patients

Study Overview
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Brief Summary
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The study design is a within-subject randomized cross-over design to evaluate the effects of DBS on sleep architecture, as measured by polysomnography, and on wake-time vigilance, as measured by a virtual reality street-crossing simulator.

Detailed Description
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In the proposed study, we will use a within-subject randomized clinical trial to measure objective changes in sleep architecture with DBS on and to compare effects of different DBS stimulation parameters on sleep architecture as measured by sleep studies. The study design will allow us to address our hypothesis that low frequency deep brain stimulation parameters are more effective than the conventional settings at improving sleep architecture and wake-time vigilance. If our hypothesis is correct, low frequency settings could be used during sleep and this would prolong stimulator battery life, therefore decreasing the frequency of required surgical battery changes for DBS. These data will be valuable in considering clinical treatment strategies and provide insight into the basic mechanisms of sleep dysfunction in PD. The study may also contribute to understanding how to achieve maximum clinical benefit from DBS while minimizing morbidity and cost.

Official Title
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The Effect of Low Frequency STN DBS on Sleep and Vigilance in PD Patients

Conditions
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Parkinson's Disease

Intervention / Treatment
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* Other: DBS stimulator setting alteration
* Other: virtual reality simulator


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects who have undergone bilateral subthalamic nucleus (STN) DBS surgery for treatment of PD. Stable DBS stimulator settings and medication regimen for at least 6 weeks prior to the sleep studies. Sleep dysfunction as measured by the Pittsburgh Sleep Quality Index (PSQI) (score >5) 19 years of age or older Ability to walk up and down stairs Exclusion Criteria: Known narcolepsy Other previous surgical treatment of Parkinson's disease(with the exception of unilateral STN DBS) including pallidotomy, thalamotomy, or gene therapy procedures. Pregnant women will be excluded from this study. Untreated obstructive sleep apnea. If obstructive sleep apnea is discovered during the first sleep study, the subject will be removed from the study. After they have been treated for at least 6 weeks with continuous positive airway pressure (CPAP), they can re-start the study. Inability to walk without assistance, including a cane, wheelchair, or walker Cognitive dysfunction that would prevent subject's ability to participate in the study. Blindness

Ages Eligible for Study
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Minimum Age: 19 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: DBS stimulator setting alteration<br> | Other: DBS stimulator setting alteration<br>* 2 sleep study options Phase I: Participants will undergo 2 sleep studies, one with the stimulator on at the subject's stable, clinically effective settings and one with the stimulator off. the order of the off and on nights will be randomized. Although blinding will be attempted, because of the significant motor effects produced with the on setting, participants may be able to tell when the DBS is OFF. In the second phase, the first sleep study night will be with the stimulator OFF. The order of the HIGH, and LOW frequency nights will be randomized 1:1 and balanced across subjects and will occur on the 2nd and 3rd PSG nights. Phase II Sleep study evaluation will include three nights of recording: 1) OFF with the stimulator off, 2) HIGH with the stimulator on at the participant's stable and clinically effective settings, and 3) LOW with the stimulator set at a low frequency that uses less energy<br>Other: virtual reality simulator<br>* This virtual pedestrian environment is a measure of real-world street-crossing behavior. This simulation is composed of an elevated platform that simulates a curb at a street-side and 3 monitors (arranged in a semi-circle) on which the subject, while wearing headtracker equipment, views the virtual environment of bidirectional traffic. When the subject deems it is safe to cross the virtual street, he/she steps off the platform/curb, which activates crossing of the street by a cartoon representation of the participant. The speed of street crossing by the cartoon is determined by each individual subject's walking speed, which is measured prior to the test.<br>* Other names: Wake time vigilance in PD patients;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in sleep efficiency between the high and low frequency nights | Phase I subjects will undergo 2 sleep studies, one with the stimulator on at the subject's stable, clinically effective settings and one with the stimulator off. Phase 2 subjects will spend the first night in the sleep lab with DBS turned off. The order of the high and low frequency nights (on the second and third study nights) will be randomized. | 3 non-consecutive nights of sleep study within 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Wake-time vigilance as measured by a virtual reality street-crossing simulator | On the morning following the high and low frequency sleep study nights, subjects will evaluated with a virtual reality street-crossing simulator as a measurement of vigilance. | 4 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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PD, Parkinson's Disease, DBS, deep brain stimulation