Impact of Preoperative Cognition on Motor Improvement in Bilateral Subthalamic Nucleus-Deep Brain Stimulation for Parkinson's Disease

Neuromodulation. 2024 Sep 28:S1094-7159(24)00672-X. doi: 10.1016/j.neurom.2024.07.011. Online ahead of print.

Abstract

Objective: This study aimed to assess the influence of preoperative cognition on postoperative motor and nonmotor outcomes in patients with Parkinson disease (PD) after deep brain stimulation (DBS).

Materials and methods: A retrospective study was performed in subjects with PD with bilateral subthalamic DBS. Preoperative cognition was indexed by Parkinson's Disease-Cognitive Rating Scale (PD-CRS) and global neuropsychological evaluation (NPE) scores. The primary outcome was change from baseline to postoperative off-drug Movement Disorders Society Unified Parkinson Disease Rating Scale (MDS-UPDRS) part 3 score. Secondary outcomes included change from baseline to postoperative MDS-UPDRS part 1 subscores.

Results: The study included 226 subjects; 176 patients (77.9%) had normal cognition (PD-NC); 48 (21.2%) had mild cognitive impairment (MCI), and two (0.9%) had PD dementia. Proportional change (-41.4% vs -52.2%, p = 0.013) in off-drug MDS-UPDRS part 3 score was smaller in PD-MCI than in PD-NC. PD-CRS (Pearson's r = 0.236, p < 0.001) and NPE (Pearson's r = 0.219, p < 0.001) scores displayed a positive correlation with proportional change in off-drug MDS-UPDRS part 3 score. Worse PD-CRS scores were related to larger improvements in MDS-UPDRS part 1.2 (hallucinations) (Pearson's r = 0.135, p = 0.045).

Conclusions: DBS induces a clinically meaningful motor improvement in patients with cognitive impairment and PD, but the improvement may be smaller than in patients who are not cognitively affected. Further research into the risk-benefit balance of DBS in people with PD and cognitive dysfunction is warranted.

Keywords: Cognition; Parkinson disease; deep brain stimulation; motor improvement.