MIRA, Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
Neuromodulation. 2011 Sep-Oct;14(5):401-10; discussion 411. doi: 10.1111/j.1525-1403.2011.00383.x. Epub 2011 Aug 19.
In spinal cord stimulation, neurosurgeons increasingly tend to implant dual leads. Dual leads (longitudinal bipole/tripole) provide medio-lateral control over the recruited dorsal column (DC) area by steering the injected cathodal currents. However, the DC recruited area is suboptimal when dual aligned leads straddling the midline programmed as longitudinal guarded cathodes (+-+) are used instead of a single lead placed over the spinal cord midline with the same configuration. As a potential improvement, an additional third lead between the two aligned leads is modeled to maximize the medio-lateral extent of the DCs at the low-thoracic vertebral region (T10-T12).
The University of Twente Spinal Cord Stimulation software (UT-SCS) is used in this modeling study. Longitudinal guarded cathodes were modeled on the low-thoracic vertebral region (T10-T12) using percutaneous triple lead configurations. The central lead was modeled over the spinal cord midline and the two lateral leads were modeled at several transverse distances to the midline lead. Medio-lateral field steering was performed with the midline lead and the second lead on each side to achieve constant anodal current ratios and variable anodal current ratios.
Reducing the transverse lead separation resulted in increasing the depths and widths of the recruited DC area. The triple lead configuration with the least transverse separation had the largest DC recruited area and usage range. The maximum DC recruited area (in terms of both depth and width) was always found to be larger under variable anodal current ratio than constant anodal current ratio conditions.
Triple leads programmed to perform as longitudinal guarded cathodes provide more postoperative flexibility than single and dual leads in covering a larger width of the low-thoracic DCs. The transverse separation between the leads is a major determinant of the area and distribution of paresthesia.
在脊髓刺激中，神经外科医生越来越倾向于植入双导联。双导联（纵双极/三极）通过引导注入的阴极电流来控制募集的背柱（DC）区域的横向控制。然而，当使用横跨中线编程为纵向保护阴极（+-+）的双对齐导联而不是放置在脊髓中线上的相同配置的单个导联时，募集的 DC 区域不理想。作为一种潜在的改进，在两个对齐的导联之间增加了第三个导联，以最大限度地扩大低胸段（T10-T12）的 DC 的横向范围。
该模型研究使用了特温特大学脊髓刺激软件（UT-SCS）。使用经皮三导联配置在低胸段（T10-T12）上进行纵向保护阴极建模。中央导联放置在脊髓中线上，两个外侧导联放置在几个与中线导联的横向距离处。通过中线导联和每侧的第二导联进行横向场引导，以实现恒定的阳极电流比和可变的阳极电流比。
减小横向导联分离会增加募集的 DC 区域的深度和宽度。具有最小横向分离的三导联配置具有最大的募集 DC 区域和使用范围。在可变阳极电流比条件下，总是发现最大的募集 DC 区域（在深度和宽度方面）大于恒定阳极电流比条件。
编程为执行纵向保护阴极的三导联在覆盖低胸段 DC 更宽的宽度方面比单导联和双导联具有更大的术后灵活性。导联之间的横向分离是感觉异常区域和分布的主要决定因素。
