The interference of experimental pain and cognition in patients suffering from chronic pain

急性疼痛是我们身体的一个重要警告信号。它发出组织损伤的信号，并允许从危险源中快速撤退，以保护我们自己。因此，疼痛感知和疼痛处理优先于其他不太相关的认知过程，从而导致疼痛处理和认知之间的干扰。这种所谓的疼痛中断功能在急性疼痛中是生理上有益的，但在慢性疼痛中失去了其保护功能。然而，患有慢性疼痛的患者经常报告疼痛引起的认知障碍，特别是注意力和记忆力缺陷，这损害了他们的生活质量。迄今为止，疼痛的中断功能几乎完全在健康样本中进行了研究，首次深入了解疼痛和认知干扰的神经机制。不幸的是，缺乏关于慢性疼痛患者疼痛有害影响的良好实验研究。因此，计划研究的目的是调查慢性腰痛患者和慢性偏头痛患者的实验性疼痛的中断作用，并将其与健康对照组进行比较。我们的目的是确定心理和神经元的预测增强或减少疼痛和认知的干扰。将使用视觉分类任务和记忆任务研究疼痛的中断效应，其中疼痛的电刺激将同时施加到下背部和前额以呈现中性图像。我们预计，患有慢性疼痛的患者将表现出更大的不利影响，由于疼痛系统的不断激活，以及由此产生的心理变化（例如注意力偏差，疼痛相关的焦虑）和神经处理的同时疼痛刺激的任务性能。在这里，我们想调查疼痛患者是否表现出增强的中断功能的疼痛一般或实验性疼痛的影响是否增加在身体部位（下背部或头部），这是受慢性疼痛条件。除了行为和生理数据外，我们还将使用（功能性）磁共振成像（fMRI;形态学和静息状态连接）获取神经数据，以识别对疼痛有害影响的高度脆弱性的心理和/或神经生物学标记。从长远来看，这些标记物可以用于识别容易受到疼痛中断影响的患者，并在多模式疼痛治疗中优化其治疗。

Acute pain is an important warning signal for our body. It signals tissue damage and allows the rapid withdrawal from the source of danger to protect ourselves. Pain perception and pain processing are therefore prioritized over other, less relevant cognitive processes, thus leading to an interference between pain processing and cognition. This so called interruptive function of pain is physiologically beneficial in acute pain, but has lost its protective function in chronic pain. However, patients suffering from chronic pain frequently report pain-induced cognitive disturbances, particularly attention and memory deficits, that impair their quality of life. To date, the interruptive function of pain has been almost entirely investigated in healthy samples, giving first insights into the neural mechanisms underlying the interference of pain and cognition. Unfortunately, well-conducted, experimental studies about the detrimental effects of pain in patients suffering from chronic pain are lacking. It is therefore the aim of the planned study to investigate the interruptive effect of experimental pain in patients suffering from chronic low back pain and patients suffering from chronic migraine and to compare them to healthy controls. We aim to identify psychological and neuronal predictors of enhanced or decreased interference of pain and cognition. The interruptive effect of pain will be investigated using a visual categorization task and a memory task, in which painful electrical stimuli will be applied to the lower back and the forehead concurrently to the presentation of neutral images. We expect that patients suffering from chronic pain will show greater detrimental effects of concurrent painful stimulation on task performance due to the constant activation of the pain system and the resulting changes in psychological (e.g. attentional biases, pain-related anxiety) and neural processing. Here, we want to investigate whether pain patients show an enhanced interruptive function of pain in general or whether the effects of experimental pain are augmented at the body site (lower back or head) that is affected by the chronic pain condition. In addition to behavioral and physiological data, we will acquire neural data using (functional) magnetic resonance imaging (fMRI; morphology and resting state connectivity) to identify psychological and/or neurobiological markers of a heightened vulnerability to the detrimental effects of pain. Such markers could, in the long-term, be used to identify patients prone to the interruptive effect of pain and to optimize their therapeutic treatment within a multimodal pain therapy.