Subthalamic high-beta oscillation informs the outcome of deep brain stimulation in patients with Parkinson's disease

Background The therapeutic effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) for Parkinson's disease (PD) is related to the modulation of pathological neural activities, particularly the synchronization in the beta band (13-35 Hz). However, whether the local beta activity in the STN region can directly predict the stimulation outcome remains unclear. Objective We tested the hypothesis that low-beta (13-20 Hz) and/or high-beta (20-35 Hz) band activities recorded from the STN region can predict DBS efficacy. Methods Local field potentials (LFPs) were recorded in 26 patients undergoing deep brain stimulation surgery in the subthalamic nucleus area. Recordings were made after the implantation of the DBS electrode prior to its connection to a stimulator. The maximum normalized powers in the theta (4-7 Hz), alpha (7-13 Hz), low-beta (13-20 Hz), high-beta (20-35 Hz), and low-gamma (40-55 Hz) subbands in the postoperatively recorded LFP were correlated with the stimulation-induced improvement in contralateral tremor or bradykinesia-rigidity. The distance between the contact selected for stimulation and the contact with the maximum subband power was correlated with the stimulation efficacy. Following the identification of the potential predictors by the significant correlations, a multiple regression analysis was performed to evaluate their effect on the outcome. Results The maximum high-beta power was positively correlated with bradykinesia-rigidity improvement (r(s) = 0.549, p < 0.0001). The distance to the contact with maximum high- power was negatively correlated with bradykinesia-rigidity improvement (r(s) = -0.452, p < 0.001). No significant correlation was observed with low- power. The maximum high-beta power and the distance to the contact with maximum high-beta power were both significant predictors for bradykinesia-rigidity improvement in the multiple regression analysis, explaining 37.4% of the variance altogether. Tremor improvement was not significantly correlated with any frequency. Conclusion High-beta oscillations, but not low-beta oscillations, recorded from the STN region with the DBS lead can inform stimulation-induced improvement in contralateral bradykinesia-rigidity in patients with PD. High-beta oscillations can help refine electrode targeting and inform contact selection for DBS therapy.