# 10-year clinical outcomes of subthalamic nucleus versus pallidal deep brain stimulation for Parkinson’s disease: VA/NINDS CSP #468F

## TL;DR

This study compares long-term outcomes of two brain stimulation targets for Parkinson's disease over 10 years.

## Contribution

The study provides the longest follow-up to date comparing subthalamic nucleus and pallidal deep brain stimulation for Parkinson’s disease.

## Key findings

- Both GPi and STN DBS improved motor function over 10 years, with no significant difference between the two targets.
- Improvements in bradykinesia and quality of life declined over time, while non-motor symptoms worsened.
- Medication reductions and improvements in dyskinesia and motor fluctuations were sustained regardless of stimulation target.

## Abstract

This study aimed to examine the very long-term effects of globus pallidus interna (GPi) or subthalamic nucleus (STN) deep brain stimulation (DBS) on Parkinson’s disease (PD) in a subset of patients enrolled in the CSP468 VA/NINDS prospective randomized trial.

The primary outcome was the change in off-medication/on-stimulation Unified Parkinson’s Disease Rating Scale III score (UPDRS III) from baseline over time between the two targets at 2, 7, and 10 years. Many secondary outcomes were also explored.

A total of 156 patients were enrolled in this substudy, and data were available for 68 GPi/49 STN participants at 7 years and 49 GPi/28 STN participants at 10 years. There was no overall difference in the time trend between the two targets (p < 0.09). UPDRS III improvements from baseline in the GPi cohort at 2, 7, and 10 years were 39.9% (p < 0.001), 16.4%, (p < 0.001), and 22.3%, (p = 0.10), respectively, and in the STN cohort at 2, 7, and 10 years it was 34.9% (p < 0.001), 16.9%, (p < 0.001), and 32.8%, (p < 0.001), respectively. Tremor subscores showed the greatest reduction, followed by rigidity subscores. Initial improvements in bradykinesia and axial subscores were attenuated, and UPDRS I, II, and III on-medication/on-stimulation scores significantly declined. UPDRS IV scores and motor diaries showed significant long-term improvement, and medication reductions were seen regardless of the target. At 7 and 10 years, the PDQ-39 total score no longer showed improvement, and more severe cognitive impairment was seen in both targets.

DBS therapy has a significant beneficial effect on overall motor function, dyskinesia, and motor fluctuations over 10 years (regardless of target), though non-motor symptoms progressed. Bradykinesia, axial, and quality-of-life improvement were maintained at 2 years and then declined over time.

ClinicalTrials.gov, identifier NCT01022073, NCT00056563, NCT01076452.