ZONA INCERTA EXHIBITS ATTENUATED BETA ACTIVITY: IMPLICATIONS FOR ADAPTIVE DEEP BRAIN STIMULATION IN PARKINSON'S DISEASE

Adaptive deep brain stimulation (aDBS) algorithms adjust stimulation delivery to the spectral power of the subthalamic nucleus (STN), thus adapting the stimulation to the motor state of patient with Parkinson´s disease (PD). To this end, a reliable estimate of STN spectral power in the beta frequency band is essential. However, STN beta-power estimates are constrained by common mode rejection, which can attenuate relevant beta signals when both recording contacts capture similar neural activity. In this context, profiling the neural activity of STN and neighboring structures may improve STN beta-power computation. We retrospectively analyzed neural activity (141 BrainSense Survey files) recorded in 24 medicated PD patients implanted with bilateral STN-DBS between 2019 and 2025. Pair contacts were anatomically localized using patient-specific MRI-CT reconstructions and classified as STN, Zona incerta (ZI), Substantia Nigra (SN), or border zones. Neural recordings were processed using a custom MATLAB pipeline to compute normalized power spectral densities in the theta, alpha, beta, and gamma frequency bands. Regional differences were assessed using linear mixed-effects models. The STN exhibited the highest beta power across regions, whereas the ZI showed significantly lower beta power and higher theta power. No difference was found in beta power between the SN and the STN. Our findings provide the first electrophysiological profiling of the subthalamic region in PD patients and suggest that ZI-referenced sensing may enhance STN beta estimation, supporting contact selection and adaptive stimulation strategies.