Image-based biophysical modeling predicts cortical potentials evoked with subthalamic deep brain stimulation

• Authors: Bryan Howell, Case Western Reserve University; Faical Isbaine, Emory University; Jon Willie, Emory University; Enrico Opri, Emory University; Robert Gross, Emory University; Coralie De Hemptinne, University of Florida; Philip A Starr, University of California San Francisco; Cameron C McIntyre, Case Western Reserve University; Svjetlana Miocinovic, Emory University
• Journal Title: BRAIN STIMULATION
• Volume: Volume 14, Number 3
• Publisher: ELSEVIER SCIENCE INC | 2021-03-27, Pages 549-563
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1016/j.brs.2021.03.009
• Subjects: Engineering, Biomedical; Health Sciences, Medicine and Surgery
• Keywords: Science & Technology; Life Sciences & Biomedicine; Clinical Neurology; Neurosciences; Neurosciences & Neurology; Deep brain stimulation; Subthalamic nucleus; Electrocorticography; Evoked potentials; Biophysical modeling; Parkinson' s disease& nbsp; PATIENT-SPECIFIC MODELS; PARKINSONS-DISEASE; ELECTRICAL-STIMULATION; MOVEMENT-DISORDERS; NERVE-FIBERS; CELL-BODIES; ACTIVATION; NUCLEUS; TISSUE; REGISTRATION

Abstract

Background: Subthalamic deep brain stimulation (DBS) is an effective surgical treatment for Parkinson's disease and continues to advance technologically with an enormous parameter space. As such, in-silico DBS modeling systems have become common tools for research and development, but their underlying methods have yet to be standardized and validated. Objective: Evaluate the accuracy of patient-specific estimates of neural pathway activations in the subthalamic region against intracranial, cortical evoked potential (EP) recordings. Methods: Pathway activations were modeled in eleven patients using the latest advances in connectomic modeling of subthalamic DBS, focusing on the hyperdirect pathway (HDP) and corticospinal/bulbar tract (CSBT) for their relevance in human research studies. Correlations between pathway activations and respective EP amplitudes were quantified. Results: Good model performance required accurate lead localization and image fusions, as well as appropriate selection of fiber diameter in the biophysical model. While optimal model parameters varied across patients, good performance could be achieved using a global set of parameters that explained 60% and 73% of electrophysiologic activations of CSBT and HDP, respectively. Moreover, restricted models fit to only EP amplitudes of eight standard (monopolar and bipolar) electrode configurations were able to extrapolate variation in EP amplitudes across other directional electrode configurations and stimulation parameters, with no significant reduction in model performance across the cohort. Conclusions: Our findings demonstrate that connectomic models of DBS with sufficient anatomical and electrical details can predict recruitment dynamics of white matter. These results will help to define connectomic modeling standards for preoperative surgical targeting and postoperative patient programming applications.