Spatial steering of deep brain stimulation volumes using a novel lead design

Objective: To investigate steering the volume of activated tissue (VTA) with deep brain stimulation (DBS) using a novel high spatial-resolution lead design. Methods: We examined the effect of asymmetric current-injection across the DBS-array on the VTA. These predictions were then evaluated acutely in a non-human primate implanted with the DBS-array, using motor side-effect thresholds as the metric for estimating VTA asymmetries. Results: Simulations show the DBS-array, with electrodes arranged together in a cylindrical configuration, can generate field distributions equivalent to commercial DBS leads, and these field distributions can be modulated using field-steering methods. Stimulation with implanted DBS-arrays showed directionally-selective muscle activation, presumably through spread of stimulation fields into portions of the corticospinal tract lying in the internal capsule. Conclusions: Our computational and experimental studies demonstrate that the DBS-array is capable of spatially selective stimulation. Displacing VTAs away from the lead's axis can be achieved using a single simple and intuitive control parameter. Significance: Optimal DBS likely requires non-uniform VTAs that may differentially affect a nucleus or fiber pathway. The DBS-array allows positioning VTAs with sub-millimeter precision, which is especially relevant for those patients with DBS leads placed in sub-optimal locations. This may present clinicians with an additional degree of freedom to optimize the DBS therapy. (c) 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.