Holsheimer J, Nuttin B, King G W, Wesselink W A, Gybels J M, de Sutter P
Institute for Biomedical Technology, University of Twente, Enschede, The Netherlands.
Neurosurgery. 1998 Mar;42(3):541-7; discussion 547-9. doi: 10.1097/00006123-199803000-00022.
The goal was to evaluate, in a clinical study, the predicted performance of the transverse tripolar system for spinal cord stimulation, particularly the steering of paresthesia, paresthesia coverage, and the therapeutic range of stimulation.
Six transverse tripolar electrodes were implanted in the lower thoracic region in four patients experiencing chronic neuropathic pain. Electrode positions, relative to the spinal cord, were estimated from computed tomographic scans. A dual-channel stimulator was used for initial percutaneous tests, and an implanted single-channel stimulator was used for follow-up test sessions. Nine "balance" settings and several cathode-anode combinations were used with the dual-channel and single-channel stimulator, respectively. In each test, the increase of paresthesia coverage from the perception threshold to the discomfort threshold was registered on a body map and the corresponding voltages were recorded.
Paresthesia steering occurred in all but one patient. The normalized steering score, enabling quantitative comparisons of paresthesia steering among tests and patients, showed that maximum paresthesia steering occurred when the electrode was at least 3 mm dorsal to the spinal cord and centered <2 mm from its midline. Paresthesia coverage included 70 to 100% of the body up to the electrode level, unless the electrode migrated or had broken wires. The therapeutic range, defined as the discomfort/perception of paresthesia threshold ratio, varied from 1.6 to 4.0.
The clinical performance of transverse tripolar stimulation is in accordance with the characteristics predicted by computer modeling. It enables finer control of paresthesia than that achieved by polarity changes in conventional spinal cord stimulation systems.
在一项临床研究中评估横向三极系统用于脊髓刺激的预测性能，特别是感觉异常的引导、感觉异常覆盖范围以及刺激的治疗范围。
在4例慢性神经性疼痛患者的下胸部区域植入6个横向三极电极。根据计算机断层扫描估计电极相对于脊髓的位置。使用双通道刺激器进行初始经皮测试，并使用植入式单通道刺激器进行后续测试。双通道和单通道刺激器分别使用9种“平衡”设置和几种阴极 - 阳极组合。在每次测试中，在人体图上记录从感觉阈值到不适阈值的感觉异常覆盖范围的增加，并记录相应的电压。
除1例患者外，其余患者均出现感觉异常引导。标准化引导评分能够对测试和患者之间的感觉异常引导进行定量比较，结果显示当电极位于脊髓背侧至少3 mm且距脊髓中线中心<2 mm时，出现最大感觉异常引导。感觉异常覆盖范围包括电极水平以下身体的70%至100%，除非电极移位或导线断裂。治疗范围定义为不适/感觉异常阈值比，范围为1.6至4.0。
横向三极刺激的临床性能与计算机建模预测的特征相符。与传统脊髓刺激系统中通过极性变化实现的控制相比，它能够更精细地控制感觉异常。
