Follow Up Study for Treatment of Parkinson's Disease With Deep Brain Stimulation (CSP#468F)

• Off-medication/On-stimulation Motor Function Score of the Unified Parkinson's Disease Rating Scale (UPDRS Part III) [ Time Frame: The change score of UPDRS Part III from baseline to 9 years post surgery ]
  The primary outcome measure for the comparison of GPi deep brain stimulation (DBS) to STN DBS is the motor function score of the Unified Parkinson's Disease Rating Scale (UPDRS Part III) measured while the patient is off medications and on stimulation at follow-up visits post surgery. UPDRS Part III has 14 items assessing motor skills including facial expression and speech, tremors, rigidity, posture, gait, and bradykinesia. Left and right sides (arms, legs, and hands) are assessed separately for seven of the functions. A summary score ranging from 0 to 108 is generated by adding the 14 specific motor function responses. The motor function (UPDRS part III) assessments are done by turning on the stimulation with and without taking PD medications (on/off) at each in-person visit. The higher the value, the worse the outcome.
  
  

Parkinson's disease (PD), the second most prevalent neurodegenerative disease (after Alzheimer's disease), affects more than a million Americans and is a common condition in the Veteran population. Although there is currently no cure for the disease, many of the symptoms of the disease can be effectively managed with medications and with deep brain stimulation (DBS). This study seeks to build upon the original CSP#468 protocol by providing an efficient long-term follow-up study. The objectives of this study are to:

determine whether the motor benefits of deep brain stimulation persist beyond two years of follow-up in patients with Parkinson's disease; determine whether the target of stimulation (GPi vs. STN) affects the durability of long-term motor improvement; define the impact of DBS on long-term function and quality of life in patients with Parkinson's disease; identify clinical features that predict favorable or unfavorable long-term outcome; and describe the long-term performance of the DBS devices, including device durability, device explanation rate, neurostimulator replacement frequency, and changes in stimulation parameters to achieve optimum symptom control.