Programming Strategy of VFS for Gait Impairments in PD

Study Overview
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Brief Summary
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Variable Frequency Stimulation(VFS) is a stimulation pattern applied in Deep Brain Stimulation(DBS) therapy for Parkinson's disease(PD). Peking Union Medical College Hospital was the first centre conducting research on VFS. The studies in the past have resembled conclusion that VFS provides improvement not only in the major symptoms such as tremor and rigidity, but also in gait and balance disorder. However, the best programming strategy of VFS has not met agreement. The random-controlled double blinded crossover study is designed for participants who underwent DBS surgery in bilateral subthalamic nucleus for parkinson's disease. The investigators study several strategies on programming and observe the improvement of symptom to look for the best one. A 4-month follow-up is designed to observe a relatively long-term effectiveness of VFS. The study intends to gather more clinical evidence to guide further studies on VFS application.

Official Title
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Programming Strategy of Variable Frequency Stimulation for Gait Impairments in Parkinson's Disease

Conditions
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Parkinson's Disease, Deep Brain Stimulation, Gait Disorders, Neurologic

Intervention / Treatment
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* Device: Programming


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Idiopathic Parkinson's disease (according to the Movement Disorder Society Clinical Diagnostic Criteria for Parkinson's Disease); 18-75 years of age; Hoehn & Yahr ≤ 3 (in best OFF-medication condition)； Implanted bilateral subthalamic nucleus DBS for over 1 year； gait Impairments in OFF-medication condition； High Frequency Stimulation provides significant improvement； in OFF-medication On-stimulation condition, capable of walking ≥ 10m. Exclusion Criteria: mental disorder or dementia; Pregnant women, lactating mothers or women who are unable to take effective measures to prevent pregnancy; With other diseases that can affect walking distance, such as joint diseases of the lower body, spinal diseases, neuropathy, or serious heart or lung diseases; In severe health condition, such as diseases associated with heart or liver; Epilepsy; Lead off target; Unable to willingly sign Written informed Consent; Disagree or unable to cooperate with follow-up sessions.

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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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: HFS-VFS<br>This arm will experience HFS first during the crossover, and then VFS. | Device: Programming<br>* programming the implanted DBS device to adjust the parameter and switch stimulation mode between Variable-Frequency settings and High-Frequency settings.<br>|
| Experimental: VFS-HFS<br>This arm will experience VFS first during the crossover, and then HFS. | Device: Programming<br>* programming the implanted DBS device to adjust the parameter and switch stimulation mode between Variable-Frequency settings and High-Frequency settings.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from Baseline 5m-Timed Up and Go test Time Result at 2 months. | Conduct a TUG test with 5m range setting and measure the time cost | Baseline, 2 months | 
| Change from Baseline 5m-Timed Up and Go test Time Result at 4 months. | Conduct a TUG test with 5m range setting and measure the time cost | Baseline, 4 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from Baseline 5m-Timed Up and Go test Step Frequency at 2 months. | Conduct a TUG test with 5m range setting and measure the step movement and calculate the step frequency | Baseline, 2 months | 
| Change from Baseline 5m-Timed Up and Go test Step Frequency at 4 months. | Conduct a TUG test with 5m range setting and measure the step movement and calculate the step frequency | Baseline, 4 months | 
| Change from Baseline 5m-Timed Up and Go test Length at 2 months. | Conduct a TUG test with 5m range setting and measure the length of each step | Baseline, 2 months | 
| Change from Baseline 5m-Timed Up and Go test Step Length at 4 months. | Conduct a TUG test with 5m range setting and measure the length of each step | Baseline, 4 months | 
| Change from Baseline 5m-Timed Up and Go test Step Variation Coefficient at 2 months. | Conduct a TUG test with 5m range setting and use the length of each step to calculate the difference coefficient | Baseline, 2 months | 
| Change from Baseline 5m-Timed Up and Go test Step Variation Coefficient at 4 months. | Conduct a TUG test with 5m range setting and use the length of each step to calculate the difference coefficient | Baseline, 4 months | 
| Change from Baseline Movement Disorder Society Unified Parkinson's Disease Rating Scale part III score at 2 months. | Conduct a Movement Disorder Society Unified Parkinson's Disease Rating Scale survey and record the score. Higher MDS UPDRS III score represents worse movement disorder symptoms. | Baseline, 2 months | 
| Change from Baseline Movement Disorder Society Unified Parkinson's Disease Rating Scale part III score at 4 months. | Conduct a Movement Disorder Society Unified Parkinson's Disease Rating Scale survey and record the score. Higher MDS UPDRS III score represents worse movement disorder symptoms. | Baseline, 4 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Parkinson's disease, Deep brain stimulation, Variable frequency stimulation, Movement disorder, Freezing of gait, Crossover study