Differential Effects of Subthalamic Nucleus and Globus Pallidus Internus Deep Brain Stimulation on Motor Subtypes in Parkinson's Disease

Abstract

To investigate differences in motor symptom change outcomes following bilateral subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation (DBS) in well-defined motor subtypes of Parkinson's disease (PD) to improve clinical decision making. We included 114 patients undergoing STN-DBS and 65 patients undergoing GPi-DBS. The patients were classified as akinetic-rigid type (ART), tremor-dominant type (TD), and mixed type (MT) based on the preoperative the Movement Disorder Society Unified Parkinson's Disease Rating Scale Part-Ⅲ (MDS-UPDRS-III) scores in the medication-off state. Outcome measures included the med-off MDS-UPDRS-III and its subscores changes at the last follow-up after surgery. Outcomes were compared among different motor subtypes and between STN-DBS and GPi-DBS. At the last follow-up (14.92 ± 8.35 months), TD patients had greater median overall motor improvement in med-off MDS-UPDRS-III scores compared with ART patients (62.90% vs 46.67%, P < 0.001), regardless of stimulation target. ART patients showed greater improvement after STN-DBS compared with GPi-DBS (54.44% vs 37.21%, P < 0.001), with improvement in rigidity, akinesia, and posture and gait disorders accounting for this difference. Our results suggest that the different PD motor subtypes show differential responses to STN-DBS and GPi-DBS, that TD patients have greater improvement than ART patients, and STN-DBS has a better effect in ART patients than GPi-DBS. Besides, different motor symptoms among different motor subtypes may respond differently to STN-DBS vs GPi-DBS. All above may reflect the heterogeneity of PD. Longer-term outcomes across different motor subtypes and stimulation targets should be further studied.