Noninvasive central modulation of pain follwing TMS inhibition of the secondary somatosensory cortex in healthy subjects

疼痛是看医生最常见的原因。它往往只能得到不适当的治疗，这一事实反映在与疼痛及其治疗相关的高昂的直接和间接成本上。因此，止痛治疗的新方法是医学上的需要。最具创新性的方法之一是对处理疼痛的大脑区域的活动进行非侵入性调节。因此，这个项目的基本假设是基于(I)发现次级躯体感觉皮质(S2)是处理疼痛强度感知的主要大脑区域，以及(Ii)通过经颅磁刺激(TMS)调节大脑浅层区域神经元活动的技术可能性。拟议的项目旨在评估通过TMS方法使S2失活是否阻碍了对没有TMS的疼痛刺激强度的区分，这些刺激被认为是明显不同的。这将确定S2在区分疼痛刺激强度方面所起的关键作用。在一项在30名健康志愿者中进行的四重交叉研究中，将比较钝化刺激(CTB)S2对伤害性刺激感知的影响，与已显示出痛觉调制效应的初级运动皮质(M1)的CTBS(阳性对照)，同时给予S2和M1的CTBS，以及S2和M1的假CTBS的影响。使用功能磁共振断层扫描，将分析CTBS刺激对疼痛基质内连通性的影响。该项目旨在建立非侵入性中枢(“自上而下”)治疗疼痛的神经科学基础。

Pain is the most common reason for seeing a doctor. It can often be treated only inadequately, a fact which is reflected in the high direct and indirect costs associated with pain and its therapy. Therefore, new approaches at analgesic treatment are a medical need. One of the most innovative approaches consists of the non-invasive modulation of the activity of pain-processing brain regions. Therefore, the underlying hypothesis of this project is based on (i) findings that the secondary somatosensory cortex (S2) is a major brain area processing the perception of pain intensity, and (ii) on the technical possibility to modulate the neuronal activity in superficial brain regions by means of transcranial magnetic stimulation (TMS). The proposed project aims at assessing whether inactivation of S2 by means of TMS impedes the distinction of the intensity of pain stimuli that without TMS were perceived as clearly distinct. This would establish the key role of S2 plays in differentiating pain stimulus intensities. In a four-fold crossover study in 30 healthy volunteers, the effects of an inactivating stimulation (cTBS) of S2 on the perception of nociceptive stimuli will be compared with those of a cTBS of the primary motor cortex (M1) where pain modulatory effects have been shown (positive control), with those of a simultaneous cTBS of S2 and M1, and those of a sham cTBS of S2 and M1. Using functional magnet resonance tomography, the effects of cTBS stimulation on the connectivity within the pain matrix will be analyzed. The project aims at establishing the neuroscientific bases of a non-invasive central ("top-down") treatment of pain.