Meulders Ann, Meulders Michel, Stouten Iris, De Bie Jozef, Vlaeyen Johan W S
Research Group Health Psychology, KU Leuven University, Leuven, Belgium; Center for Excellence on Generalization Research in Health and Psychopathology, KU Leuven University, Leuven, Belgium.
Center for Information Management, Modeling and Simulation, KU Leuven University, Leuven, Belgium; Research Group on Quantitative Psychology and Individual Differences, KU Leuven University, Leuven, Belgium.
J Pain. 2017 Jan;18(1):79-95. doi: 10.1016/j.jpain.2016.10.004. Epub 2016 Oct 22.
Fear learning deficiencies might contribute to the development and maintenance of chronic pain disability. Fear is often not restricted to movements (conditioned stimulus [CS+]) originally associated with pain (unconditioned stimulus), but expands to similar movements (generalization stimuli [GSs]). This spreading of fear becomes dysfunctional when overgeneralization to safe stimuli occurs. More importantly, persistence of pain-related fear to GSs despite corrective feedback might even be more debilitating and maintain long-term chronic pain disability. Yet, research on this topic is lacking. Using a voluntary joystick movement paradigm, we examined (extinction of) pain-related fear generalization in fibromyalgia patients (FM) and healthy control participants (HC). During acquisition, one movement (CS+) predicted pain; another did not (CS-). We tested (extinction of) fear generalization to 5 GSs varying in similarity with the CS+ and CS-. Results revealed flatter pain expectancy generalization gradients in FM than in HC due to elevated responses to GSs more similar to the CS-; the fear generalization gradients did not differ. Although pain-related fear and expectancy to the GSs decreased during extinction, responses to the GSs remained higher for FM than HC, suggesting that extinction of generalization is impaired in chronic pain patients. Persistence of excessive protective responses may contribute to maintaining long-term chronic pain disability.
Pain-related fear and expectancy to movements-varying in similarity with the original painful and nonpainful movement-decrease during extinction in HC and FM. Yet, conditioned responses remain elevated in patients despite corrective feedback, indicating impaired extinction of generalization. Persistent excessive protective responses may contribute to preserving pain disability.
恐惧学习缺陷可能导致慢性疼痛残疾的发展和维持。恐惧通常不仅限于最初与疼痛（无条件刺激）相关的动作（条件刺激[CS+]），还会扩展到类似的动作（泛化刺激[GSs]）。当过度泛化到安全刺激时，这种恐惧的扩散就会变得功能失调。更重要的是，尽管有纠正反馈，与疼痛相关的恐惧对GSs的持续存在甚至可能更使人衰弱，并维持长期的慢性疼痛残疾。然而，关于这个主题的研究却很缺乏。我们使用自愿操纵杆运动范式，研究了纤维肌痛患者（FM）和健康对照参与者（HC）中与疼痛相关的恐惧泛化（的消退情况）。在习得过程中，一种动作（CS+）预示着疼痛；另一种则不会（CS-）。我们测试了对5种与CS+和CS-相似度不同的GSs的恐惧泛化（的消退情况）。结果显示，由于对与CS-更相似的GSs反应增强，FM患者的疼痛预期泛化梯度比HC患者更平缓；恐惧泛化梯度没有差异。尽管在消退过程中，与疼痛相关的恐惧和对GSs的预期有所下降，但FM患者对GSs的反应仍高于HC患者，这表明慢性疼痛患者的泛化消退受损。过度保护反应的持续存在可能有助于维持长期的慢性疼痛残疾。
与疼痛相关的恐惧和对与最初疼痛和非疼痛动作相似度不同的动作的预期，在HC和FM患者的消退过程中都会降低。然而，尽管有纠正反馈，患者的条件反应仍然升高，表明泛化消退受损。持续的过度保护反应可能有助于维持疼痛残疾。
