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.
方法:这项多中心研究在美国7个地点进行。共纳入43例完成经皮商业SCS试验的腰腿痛患者。在移除之前,通过试验引线递送测试刺激约90分钟。SCS参数,包括振幅,频率,脉冲宽度(PW),电极配置,骑自行车,和多频刺激在测试过程中变化。感觉异常阈值(PT),舒适度(CL),感知覆盖区域,和感觉异常质量(通过患者选择关键词)被收集。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确定,对恒定频率刺激的频率不敏感(范围:20Hz-10kHz;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。被描述为舒适和刺痛的感觉对于60Hz和2.4kHz之间的频率是最常见的;不愉快的感觉通常在该范围之外更常见。有源电极之间的距离从7毫米增加到14毫米,或以1Hz的频率循环SCS波形,PT降低(p<0.0001)。最后,低频刺激的PT(即,60Hz)不受与亚PT高频刺激混合的影响。
结论:与以前研究较窄范围的工作相比,PW主要影响PT,独立于频率。感觉异常质量主要受脉冲频率的影响。这些发现促进了我们对SCS治疗的理解,并可用于改善未来的新型神经调节范例。