Machado Andre G, Gopalakrishnan Raghavan, Plow Ela B, Burgess Richard C, Mosher John C
Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, Cleveland, Ohio; Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio; and
Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, Cleveland, Ohio;
J Neurophysiol. 2014 Jul 15;112(2):276-86. doi: 10.1152/jn.00193.2014. Epub 2014 Apr 30.
Anticipating pain is important for avoiding injury; however, in chronic pain patients, anticipatory behavior can become maladaptive, leading to sensitization and limiting function. Knowledge of networks involved in pain anticipation and conditioning over time could help devise novel, better-targeted therapies. With the use of magnetoencephalography, we evaluated in 10 healthy subjects the neural processing of pain anticipation. Anticipatory cortical activity elicited by consecutive visual cues that signified imminent painful stimulus was compared with cues signifying nonpainful and no stimulus. We found that the neural processing of visually evoked pain anticipation involves the primary visual cortex along with cingulate and frontal regions. Visual cortex could quickly and independently encode and discriminate between visual cues associated with pain anticipation and no pain during preconscious phases following object presentation. When evaluating the effect of task repetition on participating cortical areas, we found that activity of prefrontal and cingulate regions was mostly prominent early on when subjects were still naive to a cue's contextual meaning. Visual cortical activity was significant throughout later phases. Although visual cortex may precisely and time efficiently decode cues anticipating pain or no pain, prefrontal areas establish the context associated with each cue. These findings have important implications toward processes involved in pain anticipation and maladaptive pain conditioning.
预期疼痛对于避免受伤很重要；然而，在慢性疼痛患者中，预期行为可能会变得适应不良，导致敏化并限制功能。了解随着时间推移参与疼痛预期和条件作用的神经网络，有助于设计新的、更有针对性的治疗方法。通过使用脑磁图，我们对10名健康受试者进行了疼痛预期的神经处理评估。将连续视觉线索引发的预期皮层活动（这些线索表示即将到来的疼痛刺激）与表示非疼痛和无刺激的线索进行比较。我们发现，视觉诱发疼痛预期的神经处理涉及初级视觉皮层以及扣带回和额叶区域。在物体呈现后的前意识阶段，视觉皮层能够快速且独立地编码并区分与疼痛预期相关的视觉线索和无疼痛的视觉线索。在评估任务重复对参与皮层区域的影响时，我们发现，当受试者对线索的上下文含义仍不了解时，前额叶和扣带回区域的活动在早期最为显著。视觉皮层活动在后期各阶段均很显著。尽管视觉皮层可能精确且高效地解码预期疼痛或无疼痛的线索，但前额叶区域会建立与每个线索相关的情境。这些发现对于疼痛预期和适应不良性疼痛条件作用所涉及的过程具有重要意义。
