Chronic Dual Target Continuous and Distributed, Adaptive Deep Brain Stimulation with Summit RC+S Are Equally Effective for Motor Symptom Control in Parkinson Disease

Introduction: We quantified the motor effects of novel, combined subthalamic nucleus (STN) plus globus pallidus (GP) continuous deep brain stimulation (cDBS) in Parkinson disease (PD), compared to an innovative, external, adaptive DBS (aDBS) control approach using local field potentials (LFPs).

Methods: We enrolled six PD subjects prospectively (NIH UH3 NS103468) following Duke IRB, FDA IDE, and Medtronic approval. The participants underwent bilateral STN + GP lead placement connected to a single Medtronic Summit RC+S. Subjects were programmed for each cDBS condition (STN alone, GP alone, STN + GP), then randomly evaluated both OFF and ON meds at one year postop, with both raters and subjects blinded. We concurrently developed a novel proportional plus integral (PI) external aDBS control program, using beta frequency LFPs. A “setpoint” decision value was initialized and refined by patient symptom control. We then compared cDBS to aDBS during research clinic sessions.

Results: UPDRS improved in all conditions both OFF and ON meds compared to OFF stimulation, improving from OFF [median (interquartile range)] [35.5 (21.2,43.4)] to STN only [22 (13.8,27.2)], GP only [24.8 (14.8,33.2)], and STN + GP [16.5 (11.1,23.4)]. Daily levodopa equivalent dosing (milligrams) was reduced from preop [1027.5 (700,1203.5)] to 1-year [240 (125,295)]. Percent of waking ON time per day without troublesome dyskinesia improved from preop [32.1% (5.4%,43.8%)] to 1-year [95.8% (89.7%,100%)]. aDBS showed similar UPDRS III scores to combined STN+GP cDBS but > 15% improvement in energy efficiency. We also compared chronic at-home cDBS to aDBS using additional outcome measures.

Conclusion : Dual STN + GP cDBS stimulation is feasible and shows improved efficacy compared to either site alone. We demonstrate a promising, external distributed approach to aDBS control possible in the Medtronic Summit RC+S, which demonstrates maintained clinical efficacy with reduced stimulation energy.