St. Jude Medical, Plano, TX, USA.
Neuromodulation. 2014 Jan;17(1):28-35; discussion 35-6. doi: 10.1111/ner.12085. Epub 2013 Jul 9.
Spinal cord stimulation (SCS) systems employ implantable pulse generators that use either a constant current (CC) or a constant voltage (CV) power source. CC power sources adjust voltage in response to resistance (impedance) to ensure that consistent current is delivered to the patient. CV power sources do not adjust voltage in response to impedance; therefore, current delivered to the patient will vary in response to changes in impedance. Both systems produce paresthesia and have been shown to treat chronic pain; however, it has been suggested that patients prefer CC stimulation over CV stimulation.
This Institutional Review Board-approved, randomized, double-blinded crossover study compared patient preference for the stimulation sensation elicited by a CC or CV neurostimulation system. Thirty patients completed a baseline evaluation prior to implantation of a percutaneous trial system and returned one-day postimplant for randomization and initiation of SCS. Three days later, patients were evaluated and crossed over into the alternate treatment group. Final evaluation of patient well-being, pain relief, satisfaction, quality of life, preference, and stimulation sensation occurred on Day 6. Patient preference was assessed using a one-sample Z-test. Treatment and group differences were explored using paired t-test for continuous and ordinal variables and chi-square of Fisher's exact test for categorical variables.
More patients (70%) preferred CC stimulation over CV stimulation (30%), and CC stimulation produced a significantly larger decrease in pain scores than CV stimulation. Interestingly, patients initially exposed to CC stimulation were less likely to be satisfied with CV stimulation.
The results from this study indicate that patients preferred and experienced greater satisfaction and pain relief with the CC system during an SCS trial period. Differences between the two systems following long-term use has yet to be compared. However, the benefits of the CC system seen with short-term use should be considered when selecting an SCS system.
脊髓刺激（SCS）系统采用可植入脉冲发生器，其使用恒流（CC）或恒压（CV）电源。CC 电源根据电阻（阻抗）调整电压，以确保向患者输送稳定的电流。CV 电源则不根据阻抗调整电压；因此，输送给患者的电流会随阻抗变化而变化。两种系统都能产生感觉异常，并已被证明可治疗慢性疼痛；然而，有人认为患者更喜欢 CC 刺激而非 CV 刺激。
这项经机构审查委员会批准的、随机、双盲交叉研究比较了患者对 CC 或 CV 神经刺激系统诱发的刺激感觉的偏好。30 名患者在植入经皮试验系统前完成基线评估，并在植入后一天返回进行随机分组和 SCS 启动。三天后，患者接受评估并交叉进入另一治疗组。第六天对患者的整体健康状况、疼痛缓解、满意度、生活质量、偏好和刺激感觉进行最终评估。使用单样本 Z 检验评估患者的偏好。使用配对 t 检验分析连续和有序变量以及卡方检验（Fisher 确切概率法）分析分类变量来探讨治疗和组间差异。
更多患者（70%）更喜欢 CC 刺激而非 CV 刺激（30%），CC 刺激使疼痛评分显著降低的幅度大于 CV 刺激。有趣的是，最初接触 CC 刺激的患者对 CV 刺激的满意度较低。
这项研究的结果表明，在 SCS 试验期间，患者更喜欢 CC 系统，并且体验到更大的满意度和疼痛缓解。长期使用两种系统后的差异尚未进行比较。然而，在选择 SCS 系统时，应考虑 CC 系统在短期使用中带来的好处。
