Su Xin, Cutinella Matthew, Agran Jason E, Dinsmoor David A
Medtronic, Inc., Restorative Therapies Group, Research & Core Technology, Minneapolis, MN, USA.
Physiological Research Laboratories, Minneapolis, MN, USA.
Neuromodulation. 2017 Dec;20(8):799-806. doi: 10.1111/ner.12710. Epub 2017 Oct 24.
The goal of this study was to compare the motor response to sacral neuromodulation (SNM) with different pairs of stimulating electrodes in anesthetized and awake sheep.
Similar to SNM clinical use in humans, the InterStim quadripolar tined lead was implanted adjacent to the S3 nerve root in sheep and bipolar stimulation was configured with one electrode negative and one electrode positive on the four contacts (0 most distal to device, 1, 2, and 3 most proximal).
Electrode 3-cathode and electrode 0-anode (3-/0+) stimulation had the lowest visual response threshold (0.46 ± 0.14V, anesthetized, 0.56 ± 0.21V, conscious), representing the most sensitive stimulation. Stimulation on electrode 0 (0-/1+) had the highest response threshold among tested electrodes (2.70 ± 0.23V, anesthetized, 3.38 ± 0.96V, conscious). The order according to response threshold from low to high was 3 < 2 < 1 < 0. The triggered response by 3-/0+ stimulation solely occurred in the perineum, tail, or bellows. In contrast, the 0-/1+ stimulation frequently evoked response in gluteal and thigh regions. The electromyographic activities from the anus were sensitive to low intensities of stimulation on electrode 3 (e.g., 3-/0+, 3-/2+).
Objective motor responses to SNM as a functional indicator for optimal lead placement may be used to demonstrate that the contact which is most proximal to the foramen (electrode 3) is an optimal electrode to trigger an "on-target" response to lower intensity stimulation. Data from this preclinical work suggest that there are several principles that may be referenced to simplify and expedite the programming process in clinical practice.
本研究的目的是比较麻醉和清醒绵羊中不同刺激电极对骶神经调节（SNM）的运动反应。
与人类SNM临床应用类似，将InterStim四极带倒刺导线植入绵羊S3神经根附近，并在四个触点（最远端为0，最近端为1、2和3）上配置双极刺激，一个电极负极，一个电极正极。
电极3阴极和电极0阳极（3-/0+）刺激的视觉反应阈值最低（麻醉状态下为0.46±0.14V，清醒状态下为0.56±0.21V），代表最敏感的刺激。电极0（0-/1+）刺激在测试电极中反应阈值最高（麻醉状态下为2.70±0.23V，清醒状态下为3.38±0.96V）。按反应阈值由低到高的顺序为3＜2＜1＜0。3-/0+刺激引发的反应仅发生在会阴部、尾部或波纹管。相比之下，0-/1+刺激经常在臀部和大腿区域诱发反应。肛门的肌电图活动对电极3上的低强度刺激敏感（例如3-/0+、3-/2+）。
作为最佳导线放置功能指标的SNM客观运动反应可用于证明最靠近椎间孔的触点（电极3）是触发对较低强度刺激的“靶点”反应的最佳电极。这项临床前研究的数据表明，有几条原则可用于简化和加快临床实践中的编程过程。
