Randomized trial of deep brain stimulation for Parkinson disease

TLDR

The study compared long‑term outcomes of GPi versus STN deep‑brain stimulation in Parkinson’s disease patients in a multicenter randomized trial. Patients were randomized to GPi or STN DBS and followed for 36 months, with motor function assessed by the UPDRS motor subscale and secondary measures of quality of life and cognition. Motor function improved similarly for both targets over 36 months, while quality‑of‑life gains waned and neurocognitive decline was faster in STN patients. Neurology 2012;79:55–65.

Abstract

<h3>Objectives:</h3> Our objective was to compare long-term outcomes of deep brain stimulation (DBS) of the globus pallidus interna (GPi) and subthalamic nucleus (STN) for patients with Parkinson disease (PD) in a multicenter randomized controlled trial. <h3>Methods:</h3> Patients randomly assigned to GPi (n = 89) or STN DBS (n = 70) were followed for 36 months. The primary outcome was motor function on stimulation/off medication using the Unified Parkinson9s Disease Rating Scale motor subscale. Secondary outcomes included quality of life and neurocognitive function. <h3>Results:</h3> Motor function improved between baseline and 36 months for GPi (41.1 to 27.1; 95% confidence interval [CI] −16.4 to −10.8; <i>p</i> &lt; 0.001) and STN (42.5 to 29.7; 95% CI −15.8 to −9.4; <i>p</i> &lt; 0.001); improvements were similar between targets and stable over time (<i>p</i> = 0.59). Health-related quality of life improved at 6 months on all subscales (all <i>p</i> values significant), but improvement diminished over time. Mattis Dementia Rating Scale scores declined faster for STN than GPi patients (<i>p</i> = 0.01); other neurocognitive measures showed gradual decline overall. <h3>Conclusions:</h3> The beneficial effect of DBS on motor function was stable and comparable by target over 36 months. Slight declines in quality of life following initial gains and gradual decline in neurocognitive function likely reflect underlying disease progression and highlight the importance of nonmotor symptoms in determining quality of life. <h3>Classification of Evidence:</h3> This study provides Class III evidence that improvement of motor symptoms of PD by DBS remains stable over 3 years and does not differ by surgical target. <i>Neurology</i>® 2012;79:55–65