García-González María, Ardizone-García Ignacio, Jiménez-Ortega Laura
Neuroscience of Emotion Cognition and Nociception Group (NeuroCEN Group), Faculty of Odontology, Complutense University of Madrid, 28040 Madrid, Spain.
Department of Clinical Dentistry, Faculty of Biomedical Sciences, European University of Madrid, 28670 Madrid, Spain.
J Oral Facial Pain Headache. 2024 Dec;38(4):61-75. doi: 10.22514/jofph.2024.039. Epub 2024 Dec 12.
The aims of the study are to analyze the influence of pain and no pain expectations on the physiological (electromyography (EMG) and pupillometry) and cognitive (Numerical Rating Scale (NRS)) response to pain. Pain expectation and no pain expectation situations were induced by employing instructional videos. The induction of pain was performed by palpating the masseter with an algometer in a sample of 2 groups: 30 healthy participants (control group) and 30 patients (Temporomandibular disorders (TMD) group) with chronic myofascial pain with referral in the masseter muscle (Diagnostic Criteria for Temporomandibular Dissorders (DC/TMD)). Used a mixed design all participants were exposed to pain and no pain conditions in the same session, but the order of the presentation was counterbalanced across participants to control its possible influence. A significantly larger pupillary diameter was observed in the pain expectation relative to the no pain expectation condition in both groups. The TMD group presented larger EMG activity and larger scores in anxiety, somatization, catastrophizing and central sensitization than the control group. In the NRS, the TMD group also showed a significantly higher score than the control group. The TMD group presented similar NRS scores in the expectation condition compared to the no pain expectation condition, while the control group presented higher scores for pain expectation than for no pain expectation. Pain expectation modulated the pain cognitive pain assessment and pupil diameter in controls. The cognitive pain assessment was altered in the TMD group compared to the control group, particularly in the no pain expectation condition, this may be due to a negative reappraisal of pain due to past experiences, as pointed out by the observed level of catastrophizing. Pain expectations did not influence the EMG, significantly higher EMG activity was found in the TMD group compared to the control group regardless of expectation type.
本研究的目的是分析疼痛预期和无疼痛预期对疼痛的生理（肌电图（EMG）和瞳孔测量）和认知（数字评定量表（NRS））反应的影响。通过使用教学视频诱导产生疼痛预期和无疼痛预期的情境。在两组样本中通过用压痛计触压咬肌来诱导疼痛：30名健康参与者（对照组）和30名患有慢性肌筋膜疼痛且咬肌有牵涉痛的患者（颞下颌关节紊乱（TMD）组）（颞下颌关节紊乱诊断标准（DC/TMD））。采用混合设计，所有参与者在同一会话中暴露于疼痛和无疼痛条件下，但呈现顺序在参与者之间进行了平衡，以控制其可能的影响。与无疼痛预期条件相比，两组在疼痛预期时均观察到瞳孔直径显著增大。TMD组比对照组表现出更大的肌电活动，在焦虑、躯体化、灾难化和中枢敏化方面得分更高。在NRS中，TMD组的得分也显著高于对照组。与无疼痛预期条件相比，TMD组在预期条件下的NRS得分相似，而对照组在疼痛预期时的得分高于无疼痛预期时。疼痛预期调节了对照组的疼痛认知评估和瞳孔直径。与对照组相比，TMD组的认知疼痛评估发生了改变，特别是在无疼痛预期条件下，这可能是由于过去经历对疼痛的负面重新评估，如观察到的灾难化水平所指出的那样。疼痛预期并未影响肌电图，无论预期类型如何，TMD组的肌电活动均显著高于对照组。
