主动控制和刺激的组合方式对经皮神经电刺激镇痛效果的影响及其机制研究

发布时间：2018-09-13 15:23

【摘要】：理论及临床研究均表明经皮神经电刺激(TENS)具有镇痛作用。上世纪70年代,TENS开始应用于临床,并在很多临床疼痛治疗中取得了良好的疗效。如TENS在缓解术后痛、慢性疼痛、女性痛经和分娩痛以及其他疼痛性疾病上均发挥了重要作用。TENS的镇痛效果受到众多自身及其他外界因素的影响。很多研究证明了TENS电极的安放位置、脉冲参数(包括电流强度、电流频率、脉宽、治疗时间及使用频率)、个体差异等都会影响TENS的镇痛效果。除了上述影响因素外,研究者们发现将不同脉冲参数的电针刺激(均引发痛觉)结合可以起到更好的镇痛效果,并且结合的方式不同,镇痛效果也有差异。本研究的实验一首次将触觉刺激和痛觉刺激以两种不同的方式结合起来,探讨这两种结合方式在镇痛效果上的差异。另外,当感觉刺激是由自发的行为所触发时,对刺激的感知会有所减弱,这一现象已广为人知。预期行为效应的正向模型和实际感觉反馈之间的一致性可以解释这种现象。特别地,运动过程和触觉感知之间的连接所引发的大脑状态可以通过自上而下的控制来选通伤害性信息,从而起到抑制功能。因为大脑状态能随意影响对随后不同感觉模态刺激的感知,所以我们假设在自发的触觉刺激之后给予伤害性刺激以及在非自发的触觉刺激之后给予伤害性刺激,前者所诱发的疼痛要明显低于后者。因此本研究的实验二将比较TENS由患者自行控制来给予刺激和由外部决定来给予刺激这两种情况下TENS的镇痛效果。实验一考察了以两种方式结合的TENS的镇痛效果。实验中4Hz和100Hz的电刺激有两种结合方式:(1)这两种频率的刺激波由一对电极交替给予,形成疏密波;(2)这两种频率的刺激波由两对电极同时给予,形成同时波。结果表明以这两种方式结合的TENS的镇痛效果(强度的减弱,不愉悦感的下降)没有差异。实验结果与预期及前人研究不一致,可能的原因有本研究“以触镇痛”和“以痛镇痛”的TENS的结合不同于前人“以痛镇痛”和“以痛镇痛”的电针刺激的结合。另外,本研究以人为实验对象,不同于前人以老鼠为实验对象;最后本研究的结果在统计学上没有差异,但是从描述统计上来看,疏密波的镇痛效果有优于同时波的镇痛效果的趋势,但是可能由于被试量比较少,这种趋势在统计学上不显著。未来研究可以增加被试进一步对两种结合方式的镇痛效果进行研究。实验二考察了被试在两种不同的条件下(自主控制触觉刺激/非自主控制触觉刺激)接受相同的伤害性激光刺激所产生的心理物理以及神经生理反应。这两种条件分别是:自发的触觉条件(Self-initiated Tactile Sensation,STS)以及非自发的触觉条件(Non Self-initiated Tactile Sensation,N-STS)。我们观察到在STS条件下疼痛的强度和不愉悦度,以及激光诱发的脑响应相较于N-STS条件下有了显著的下降。除此之外,在STS条件下激光刺激开始之前的alpha和beta响应的大小要显著大于N-STS条件下的响应的大小。这些结果证实了当被试可以按照自己的意愿选择何时触发触觉刺激时,那么对疼痛的感知以及与疼痛相关的脑响应都会减弱,并且该研究利用神经响应来反映运动过程和感觉反馈之间的连接。因此,我们的研究不仅详细阐述了我们对这样一种根本的神经机制的理解,即触觉诱发镇痛作用的自上而下的调节的神经机制,而且也为如何在各种临床应用中更好地发挥镇痛作用提供了理论依据。
[Abstract]:Theoretical and clinical studies have shown that transcutaneous electrical nerve stimulation (TENS) has analgesic effects. In the 1970s, TENS began to be used in clinic and achieved good results in many clinical pain treatments. For example, TENS has played an important role in relieving postoperative pain, chronic pain, female dysmenorrhea, labor pain and other pain diseases. Many studies have shown that the placement of TENS electrodes, pulse parameters (including current intensity, current frequency, pulse width, treatment time and frequency), and individual differences all affect the analgesic effect of TENS. The combination of electroacupuncture stimulation with impulse parameters (both triggering pain) can have better analgesic effect, and the analgesic effect is different in different ways. In the first experiment of this study, tactile stimulation and pain stimulation were combined in two different ways to explore the difference of analgesic effect between the two methods. It is well known that when stimuli are triggered by spontaneous behavior, the perception of stimuli decreases. Consistency between the forward model of expected behavioral effects and actual sensory feedback can explain this phenomenon. In particular, the connection between motor processes and tactile perception can trigger brain states from top to bottom. Because the state of the brain can arbitrarily affect perception of subsequent sensory modality stimuli, we assume that nociceptive stimuli are given after spontaneous tactile stimuli, and nociceptive stimuli are given after non-spontaneous tactile stimuli, with the former causing significant pain. The analgesic effect of TENS was compared between the patient-controlled stimulation and the externally determined stimulation. Experiment 1 examined the analgesic effect of TENS combined in two ways. The results showed that there was no difference in the analgesic effect of TENS with the combination of the two methods (the decrease of intensity, the decrease of unpleasant feeling). The experimental results were inconsistent with the expectations and previous studies, and the possible reasons were as follows. In this study, the combination of "touch analgesia" and "pain analgesia" TENS was different from the combination of "pain analgesia" and "pain analgesia" electroacupuncture stimulation. In conclusion, the analgesic effect of dense wave is superior to that of simultaneous wave, but this trend is not statistically significant because the number of subjects is relatively small. Future studies may increase the study of analgesic effect of the two combination methods. The psychophysiological and neurophysiological responses to the same noxious laser stimulation are controlled tactile stimulation/uncontrolled tactile stimulation. The two conditions are: spontaneous self-initiated Tactile Sensation (STS) and non-spontaneous tactile sensation (N-STS). In addition, the alpha and beta responses before the onset of laser stimulation in STS were significantly greater than those under N-STS. These results confirm that the subjects can respond according to the experimental data. Choosing when to trigger a tactile stimulus according to one's own preference weakens both pain perception and pain-related brain responses, and this study uses neural responses to reflect the connections between motor processes and sensory feedback. Solution, that is, the neural mechanism of top-down regulation of tactile-induced analgesia, also provides a theoretical basis for how to play a better analgesic role in various clinical applications.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：B845

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