Deep brain stimulation (DBS) has become an important tool in the management of a wide spectrum of diseases in neurology and psychiatry. Target selection is a vital aspect of DBS so that only the desired areas are stimulated. Segmented leads and current steering have been shown to be a promising addition to DBS technology enabling better control of the stimulating electric field. Recently introduced orientation selective DBS (OS-DBS) is a related development permitting sensitization of the stimulus to axonal pathways with different orientations by freely controlling the primary direction of the electric field using multiple contacts. Here, we used OS-DBS to stimulate the subthalamic nucleus (STN) in healthy rats while simultaneously monitoring the induced brain activity with fMRI. Maximal activation of the sensorimotor and basal ganglia-thalamocortical networks was observed when the electric field was aligned with the STN pointing laterally in the mediolateral direction, while no cortical activation was observed with the electric field pointing medially to the opposite direction. Such findings are consistent with mediolateral main direction of the STN fibers, as seen with high resolution diffusion imaging and histology. The asymmetry of the OS-DBS dipolar field distribution using three contacts along with the potential stimulation of the internal capsule, are also discussed. We conclude that OS-DBS offers an additional degree of flexibility for optimization of DBS of the STN which may enable a better treatment response.

中文翻译：

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大鼠丘脑底核定向选择性脑深部刺激

深部脑刺激 (DBS) 已成为管理神经病学和精神病学中广泛疾病的重要工具。目标选择是 DBS 的一个重要方面，因此只刺激所需的区域。分段引线和电流控制已被证明是 DBS 技术的一个有前途的补充，能够更好地控制刺激电场。最近推出的定向选择性 DBS (OS-DBS) 是一项相关开发，通过使用多个接触自由控制电场的主要方向，允许刺激对不同方向的轴突通路敏感。在这里，我们使用 OS-DBS 刺激健康大鼠的丘脑底核 (STN)，同时用 fMRI 监测诱导的大脑活动。当电场与指向中外侧方向的 STN 对齐时，观察到感觉运动和基底神经节 - 丘脑皮质网络的最大激活，而在内侧指向相反方向的电场时未观察到皮质激活。这些发现与 STN 纤维的内侧主方向一致，如高分辨率扩散成像和组织学所见。还讨论了使用三个接触以及内囊的潜在刺激的 OS-DBS 偶极场分布的不对称性。我们得出结论，OS-DBS 为优化 STN 的 DBS 提供了额外的灵活性，这可以实现更好的治疗反应。