Deep brain stimulation effects on cortical activity across frequency bands and contact locations

Abstract Deep brain stimulation is an effective treatment for Parkinson’s disease, but clinical programming remains subjective and time-consuming. Neurophysiological biomarkers may offer an objective and scalable approach to guide stimulation settings. To examine whether cortical oscillations—particularly in alpha, beta, and narrowband gamma bands—reflect deep brain stimulation parameter changes and their dependency on the stimulating contact location. Thirteen Parkinson’s patients with subthalamic deep brain stimulation (21 hemispheres) underwent electroencephalography during routine programming sessions. Arm-task segments across multiple stimulation amplitudes were analysed. Alpha (8–12 Hz), beta (13–30 Hz), and narrowband gamma (60–90 Hz) power and burst features were extracted from the ipsilateral motor cortex. Volumes of tissue activated were computed and overlapped with the motor subthalamic nucleus to assess stimulation targeting. Relationships between neurophysiological features, stimulation amplitude, motor subthalamic-nucleus overlap, and active contact location were evaluated. Cortical alpha burst amplitude and duration significantly decreased with stimulation amplitude—but only when active contacts were located within the motor subthalamic-nucleus. Cortical beta-band features showed no significant modulation across amplitudes or locations. Cortical narrowband gamma power and burst rate increased with stimulation amplitude, especially when stimulation overlapped with the motor subthalamic-nucleus, though effects were less spatially specific than for alpha. Cortical alpha and narrowband gamma oscillations provide sensitive and complementary physiomarkers of deep brain stimulation parameter change. Alpha dynamics reflect spatially precise stimulation within the motor subthalamic-nucleus, while narrowband gamma scales with amplitude. These features may support EEG-guided programming and future adaptive deep brain stimulation strategies. Competing Interest Statement The authors have declared no competing interest. Funding Statement This study did not receive any funding Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: London - Harrow Research Ethics Committee gave ethical approval for this work I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability Data produced in the present study are available upon reasonable request to the authors