Clinical Evaluation of the Infinity Deep Brain Stimulation System

Study Overview
=================
Brief Summary
-----------------
The purpose of this post-market study is to characterize the clinical performance of the Infinity Deep Brain Stimulation (DBS) system, including the Implantable Pulse Generator (IPG), directional DBS leads, extensions, iPad clinician programmer, iPod patient controller and related system components.

Official Title
-----------------
Post Market Clinical Follow Up Evaluating the Infinity Deep Brain Stimulation Implantable Pulse Generator System

Conditions
-----------------
Parkinson Disease

Intervention / Treatment
-----------------
* Device: Omnidirectional stimulation
* Device: Directional stimulation


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Subject is able to provide informed consent; Subject is diagnosed with Parkinson's disease (PD) and has been recommended to receive an Infinity DBS system with a bilateral DBS implant in the Subthalamic Nucleus (STN), or has received an implant of an Infinity system with bilateral lead implants in the STN; Subject must be available for follow-up visits. Exclusion Criteria: Subject is not a surgical candidate; In the investigator's opinion, the subject is unable to tolerate multiple programming sessions within a single setting; Subject is unable to comply with the follow-up schedule.
Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Intervention Model: Crossover Assignment
Interventional Model Description: Single-arm crossover study, with double-blind, randomized sequence of testing for primary endpoint. Although this was a crossover study, the primary endpoint was a double-blind randomized controlled assessment of therapeutic window during the 3-month clinic visit. Subjects received both directional and omnidirectional stimulation, and the order was randomized.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Omnidirectional followed by directional DBS<br>Omnidirectional DBS is used for the first 3 months in all subjects, unless not tolerated. Directional DBS is used for months 3-6 in all subjects with a directional DBS lead. Primary endpoint is based on double-blind testing of omnidirectional vs. directional DBS in randomized order at 3-month follow-up visit. | Device: Omnidirectional stimulation<br>* At the 3-month follow-up, therapeutic window, symptom relief and side effect thresholds are evaluated at the best level for omnidirectional stimulation with the Infinity DBS lead.<br>Device: Directional stimulation<br>* At the 3-month follow-up, therapeutic window, symptom relief and side effect thresholds are evaluated using directional contacts at the best segmented level of the Infinity DBS lead.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants With Wider Therapeutic Window With Directional Programming (Superiority) | Therapeutic window is the range of stimulation amplitude that produces symptom relief without causing side effects. Proportion of subjects with a wider therapeutic window using directional stimulation, compared to a threshold of 60%. Based on randomized, double-blind evaluation using within-subject control. | 3-month follow-up visit after initial programming | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants With Wider Therapeutic Window With Directional Programming (Non-inferiority) | Therapeutic window is the range of stimulation amplitude that produces symptom relief without causing side effects. The proportion of subjects with wider therapeutic window using directional stimulation will be compared to a performance goal of 60% with a non-inferiority threshold of 40%. Based on randomized, double-blind evaluation using within-subject control. | 3-month follow-up visit after initial programming | 
| Change in UPDRS III Score on and Off Stimulation (Medication on) at 3 and 6 Months | Change with stimulation on vs. off in Unified Parkinson's Disease Rating Scale (UPDRS) part III motor examination at 3 months using omnidirectional stimulation, compared to 6 months using directional stimulation. UPDRS part III contains 27 questions used to measures severity of Parkinson's motor symptoms. The range of scores is 0 to 108, with higher score indicating greater symptoms. Subjects are on medication for the assessment. | 3-month and 6-month follow-up visits |