Central mechanisms of chronic trigeminal pain

描述(申请人提供)：颞颌关节紊乱病(TMD)影响约7-17%的美国成年人口。启动和维持TMD的机制尚不清楚；然而，最近的研究表明，TMD与内分泌、自主神经和中枢神经系统功能有关。这项建议将结合功能磁共振成像(FMRI)结合疼痛测试程序的最新进展来评估人类TMD患者中枢神经系统的病理生理变化以及这些变化与肌肉疼痛的关系。目标1将使用独特的疼痛测试程序，提供对痛苦、焦虑和其他心理因素的有效控制措施，以评估为什么TMD患者面部的敏感性是区域性的，即如何以及为什么肌肉中的某些部位高度敏感，而其他肌肉部位在疼痛反应谱中相对“正常”。目标2涉及开发一种用于功能磁共振成像环境的三叉神经疼痛测试方法。整个中枢疼痛通路的神经活动，特别是三叉神经中央柱内的神经活动，将与诱发疼痛一起研究，以检验中枢回路以特定症状的方式敏化的假设。将特别注意相对无痛部位、相对疼痛部位和具有疼痛转诊模式的触发点部位之间的差异。这项拟议的研究将首次对TMD患者的三叉神经通路进行系统的神经成像。这些研究可能从根本上改变对这类患者的评估和治疗方式。这些结果将有助于为诊断、选择治疗方法和评估治疗效果的机械驱动、非侵入性疼痛测试程序提供必要的知识库。这些方法也将有助于TMD生物学基础的基础研究，例如，未来的工作可以使用诱发疼痛测试和神经成像方法来研究内分泌、性激素、遗传和其他可能与TMD的病因和病理生理有关的生物学机制。

DESCRIPTION (provided by applicant): Temporomandibular disorders (TMD) affect ~ 7- 17% of the American adult population. The mechanisms that initiate and maintain TMD are not well understood; however, recent work suggests links to endocrine, autonomic and central nervous system function. This proposal will use recent advances in pain testing procedures in conjunction with functional magnetic resonance imaging (fMRI) to evaluate pathophysiological changes in the central nervous systems of human TMD patients and the association of these changes with muscle pain. Aim 1 will use unique pain testing procedures, which offer a proven measure of control over distress, anxiety and other psychological factors, to evaluate why sensitivity in the faces of TMD sufferers is regional, i.e., how and why are some sites in muscles hypersensitive whereas other muscle sites are relatively 'normal' in pain response profiles. Aim 2 involves developing a trigeminal pain testing methodology for use within the fMRI environment. Neural activity throughout central pain pathways in general and within the central trigeminal columns in particular will be studied in association with evoked pain to test the hypothesis that central circuitry is sensitized in symptomatically-specific ways. Particular attention will be paid to differences between relatively pain-free sites, relatively painful sites, and trigger point sites with pain referral patterns. The proposed studies will provide the first systematic neural imaging of trigeminal pathways in TMD sufferers. These studies could fundamentally change how such patients are evaluated and treated. The results will contribute to the knowledge base necessary for mechanistically-driven, non-invasive pain testing procedures for diagnosis, selection of treatments, and evaluation of treatment efficacy. These methods will also be useful in basic investigations of the biological basis of TMD, e.g., future work can use the evoked pain testing and neural imaging methods to study endocrine, sex hormone, genetic and other biological mechanisms that likely contribute to the etiology and pathophysiology of TMD.