Distinct subthalamic and pallidal beta dynamics in Parkinson’s disease

Despite the clinical use as a Deep Brain Stimulation (DBS) target in Parkinson’s disease (PD) and recent approval for adaptive stimulation, beta dynamics in the Globus Pallidus internus (GPi) remain poorly defined compared to the Subthalamic Nucleus (STN). We investigated target-specific beta activity in Local Field Potentials recorded in PD patients implanted with sensing-enabled STN- or GPi-DBS and examined differential modulation by L-Dopa and stimulation and relationship with motor symptoms. In the untreated state, spectral profiles were comparable between targets. L-Dopa selectively reduced low-beta power and burst durations in the STN, while suppressing high-beta activity in the GPi. DBS induced broadband beta suppression and burst shortening in the STN, whereas attenuated pallidal high-beta oscillations. Clinical improvement correlated with low-beta modulation in STN patients and high-beta modulation in GPi patients. Low- and high-beta sub-bands exhibit distinct target-specific pathophysiological behaviour and responsiveness. These findings provide a physiological framework for frequency-tailored adaptive DBS.