The Correlation of Reduction of Levodopa and Non-motor Symptoms of Parkinson's Disease After Deep Brain Stimulation

Study Overview
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Brief Summary
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Patients with parkinson disease (PD) usually reduced the dose the levodopa after received deep brain stimulation (DBS). However, studies seldomly mentioned about the influences on non-motors systems after the reduction. Our study focused on the changes after DBS and attribute them to the levodopa variety.

Detailed Description
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We calculated that group sample sizes of 126 patients (63 in group 1; 63 in group 2) would provide 80% power to reject the null hypothesis of equal means when the mean difference is -5(10-15) with standard deviations of 10 for test group and 10 for control group at a two-sided alpha of 0.05. Given an anticipated dropout rate of 20%, total sample size required is 158 (79 in reduction; 79 in non-reduction group). Written informed consent was obtained from all participants. After the baseline measurement, we informed the eligible patients the assigned randomization group with sealed opaque envelopes marked with the inpatient numbers . Within 12 months after STN-DBS, the LEDD of the intervention group was consistent with that before operation, and gradually decreased under the guidance of physician according to the expert consensus of DBS after 12 months. The compliance problem was solved by determining the actual number of antiparkinsonian medications returned by participants.

Official Title
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The Correlation of Reduction of Levodopa and Non-motor Symptoms of Parkinson's Disease After Deep Brain Stimulation

Conditions
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Parkinson Disease, Visual Impairment

Intervention / Treatment
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* Drug: Levodopa


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants underwent neuro-ophthalmologic examinations, including ocular fundus photography, automated perimetry, and OCT. Patients undergoing deep brain stimulation (DBS) took an extra VIPD-Q after the operation. Exclusion Criteria: secondary causes of parkinsonism, prior brain surgery (except DBS), glaucoma, intraocular surgery, diabetes and other diseases affecting the visual field or neurologic systems, and the current use of medications affecting visual function.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Levodopa Reduction Group After STN-DBS<br>Patients in this group started to reduce levodopa dose 1 months after STN-DBS | |
| Experimental: Levodopa non-Reduction Group After SNT-DBS<br>Patients in this group did not reduce levodopa dose until 12 months after STN-DBS | Drug: Levodopa<br>* Some patients did not reduced the dose of levodopa after STN-DBS comparing to some without reducing the dose.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| VIPD-Q scores after STN-DBS | The VIPD-Q scores was recorded 12 months after STN-DBS | 12 months after STN-DBS | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| RNFL thickness |  | 12 months after STN-DBS | 
| Vessel density in ocular fundus |  | 12 months after STN-DBS | 
| Saccades with DBS on status |  | 1 months after STN-DBS | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Deep Brain Stimulation, Levodopa