Objectives

Recent developments in spinal cord stimulation (SCS) programming have initiated new modalities of imperceptible stimulation. However, the boundaries of sensory perception are not well defined. The BEnchtop NEuromodulation Following endIng of Trial study aimed to create a map of perceptual threshold responses across a broad range of SCS parameters and programming to inform subperception therapy design.

Materials and Methods

This multicenter study was conducted at seven US sites. A total of 43 patients with low back and/or leg pain who completed a percutaneous commercial SCS trial were enrolled. Test stimulation was delivered through trial leads for approximately 90 minutes before removal. SCS parameters, including amplitude, frequency, pulse width (PW), electrode configuration, cycling, and multifrequency stimulation were varied during testing. Paresthesia threshold (PT), comfort level (CL), perceptual coverage area, and paresthesia quality (through patient selection of keywords) were collected. Differences were evaluated with analysis of variance followed by post hoc multiple comparisons using t-tests with Bonferroni correction.

Results

PT was primarily determined by PW and was insensitive to frequency for constant frequency stimulation (range: 20 Hz–10 kHz; F(1284) = 69.58, p < 0.0001). For all tests, CL was approximately 25% higher than PT. The dominant variable that influenced paresthesia quality was frequency. Sensations described as comfortable and tingling were most common for frequencies between 60 Hz and 2.4 kHz; unpleasant sensations were generally more common outside this range. Increasing distance between active electrodes from 7 mm to 14 mm, or cycling the SCS waveform at 1 Hz, decreased PT (p < 0.0001). Finally, PT for a low-frequency stimulus (ie, 60 Hz) was unaffected by mixing with a sub-PT high-frequency stimulus.

Conclusions

In contrast to previous work investigating narrower ranges, PW primarily influenced PT, independently of frequency. Paresthesia quality was primarily influenced by pulse frequency. These findings advance our understanding of SCS therapy and may be used to improve future novel neuromodulation paradigms.

中文翻译：

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定义脊髓刺激编程中患者感知的界限

目标

脊髓刺激（SCS）编程的最新发展开创了新的难以察觉的刺激方式。然而，感官知觉的界限尚未明确界定。试验结束后的 BEnchtop 神经调节研究旨在创建一系列 SCS 参数和编程的知觉阈值反应图，为亚知觉治疗设计提供信息。

材料和方法

这项多中心研究在美国七个地点进行。共有 43 名腰痛和/或腿部疼痛的患者完成了经皮商业 SCS 试验。在移除之前，通过试验引线传递测试刺激约 90 分钟。SCS 参数，包括振幅、频率、脉冲宽度 (PW)、电极配置、循环和多频刺激在测试过程中发生变化。收集感觉异常阈值（PT）、舒适度（CL）、知觉覆盖面积和感觉异常质量（通过患者选择关键词）。通过方差分析评估差异，然后使用带有 Bonferroni 校正的t检验进行事后多重比较。

结果

PT 主要由 PW 决定，对恒定频率刺激的频率不敏感（范围：20 Hz–10 kHz；F(1284) = 69.58，p  < 0.0001）。对于所有测试，CL 比 PT 高约 25%。影响感觉异常质量的主要变量是频率。频率在 60 Hz 到 2.4 kHz 之间时，最常见的感觉是舒适和刺痛感；在此范围之外，不愉快的感觉通常更常见。将有源电极之间的距离从 7 mm 增加到 14 mm，或以 1 Hz 循环 SCS 波形，会降低 PT ( p  < 0.0001)。最后，低频刺激（即 60 Hz）的 PT 不受与亚 PT 高频刺激混合的影响。

结论

与之前研究更窄范围的工作相比，PW 主要影响 PT，与频率无关。感觉异常质量主要受脉冲频率的影响。这些发现增进了我们对 SCS 疗法的理解，并可用于改进未来的新型神经调节范例。