Subthalamic beta peak power ratio as an electrophysiological marker for deep brain stimulation contact selection in Parkinson's disease.

BACKGROUND: Previous studies have demonstrated that patients with Parkinson's disease (PD) exhibit pathologically increased beta band activity (12-35 Hz) in the basal ganglia, which peaks at an individual frequency and correlates with symptom severity. The purpose of this study was to determine whether different beta peak measures can serve as predictors for deep brain stimulation (DBS) contact selection. METHODS: Subthalamic local field potentials were acquired from 27 patients with PD (8 female, 59.0 ± 8.9 years) with (ON) and without (OFF) dopaminergic medication. Peak amplitudes and frequencies were detected in the low (12-20 Hz) and high beta band (21-35 Hz), and their predictive value for the motor symptom improvement, the therapeutic window and the optimal stimulation contact were analyzed. RESULTS: In particular, the power ratio of the highest low beta peak ON versus OFF medication explained 23.7% of the variance in the therapeutic window. CONCLUSION: Our results demonstrate that beta peak measures can serve as valuable markers to estimate contact selection to achieve an optimal DBS outcome in patients with PD. TRIAL REGISTRATION: Not applicable.