Neuronal correlates of pain controllability in chronic musculoskeletal pain patients

反复疼痛发作的不可控性是制约慢性疼痛患者生活质量的最大因素之一。可控性对疼痛的影响和潜在的脑调节机制在慢性疼痛患者中尚不清楚，到目前为止只在健康对照组(HC)中进行了研究。但对实验性疼痛过程中涉及疼痛可控性的潜在脑机制及其在慢性肌肉骨骼疼痛患者(如纤维肌痛综合征(FMS)患者)中的潜在干扰的了解有助于改进慢性疼痛的治疗。这一机制的知识可以在未来的研究中用于测试认知行为方法是否可以恢复这一大脑机制，并在必要时调整治疗方法。由于FMS组的疼痛可能比HC组更显著，因为他们有与疼痛相关的学习史，我们也将测量对不愉快音调的可控性，这将在两组中调整为同等显著，并且没有与之相关的学习史。我们想要检查可控性对FMS患者和30名HC患者的不愉快听觉刺激和痛觉的影响及其神经元相关性。样本描述的临床特征将通过问卷调查进行评估，以确保与现有出版物样本的可比性(抑郁、焦虑、疼痛、灾难、疼痛焦虑和控制点)。听觉刺激和疼痛刺激将分别在两种情况下使用：自我控制(受试者自己可以停止刺激)和外部控制(受试者认为计算机停止刺激)。刺激的长度将是平行的，出现的顺序将是随机的。这种设计以前被证明在调节可控性方面是有效的(Wiech等人。2006)。

The uncontrollability of repetitive pain attacks is one of the most restricting factors for life-quality in chronic pain patients. The influence of controllability on pain and the underlying modulating brain mechanisms are not known in chronic pain patients and have so far only been investigated in healthy controls (HC). But the understanding of the underlying brain mechanism involved in controllability of pain during experimental pain and its potential disturbance in chronic musculoskeletal pain patients (e.g. patients with fibromyalgia syndrome (FMS)) could help to improve chronic pain treatments. The knowledge of this mechanism could be used in future studies to test if cognitive behavioral approaches could retrieve this brain mechanism and if necessary adapt treatment approaches. As pain could be more salient in the FMS group compared to the HC, because of their learning history with pain, we will also measure controllability over an unpleasant tone, which will be adjusted as equal salient in both groups and has no learning history connected with it.We want to examine the effect of controllability on unpleasant auditory stimuli and pain perception and their neuronal correlates in 30 patients with FMS as well as 30 HC. Clinical characteristics for the description of the sample to ensure comparability with samples of existing publications (depression, anxiety, pain, catastrophizing, anxiety about pain, and locus of control) will be assessed by questionnaires. Auditory and painful stimuli will be applied under two conditions each: self-controlled (subjects themselves can stop the stimulation) and externally-controlled (subjects believe a computer stops the stimulation). The length of the stimulation will be parallelized and the order of appearance will be randomized. This design was previously shown to be effective in modulating controllability (Wiech et al. 2006).