Farmer Adam D, Aziz Qasim
Centre for Digestive Diseases, Blizard Institute, Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine & Dentistry, Queen Mary University of London, London E1 2AJ, UK.
Scand J Pain. 2014 Apr 1;5(2):51-60. doi: 10.1016/j.sjpain.2014.01.002.
Background and aims Chronic visceral pain is common both in patients with identifiable organic disease and also in those without any structural, biochemical or immunological abnormality such as in the functional gastrointestinal disorders (FGIDs). We aim to provide a contemporaneous summary of pathways involved in visceral nociception and how a variety of mechanisms may influence an individual's experience of visceral pain. Methods In this narrative review, we have brought together evidence through a detailed search of Medline in addition to using our experience and exposure to recent research developments from ourselves and other research groups. Results FGIDs are a heterogeneous group of disorders whose aetiology largely remains an enigma. The germane hypothesis for the genesis and maintenance of chronic visceral pain in FGIDs is the concept of visceral hypersensitivity. A number of peripheral and central mechanisms have been proposed to account for this epiphenomenon. In the periphery, inflammatory mediators activate and sensitize nociceptive afferent nerves by reducing their transduction thresholds and by inducing the expression and recruitment of hitherto silent nociceptors culminating in an increase in pain sensitivity at the site of injury known as primary hyperalgesia. Centrally, secondary hyperalgesia, defined as an increase in pain sensitivity in anatomically distinct sites, occurs at the level of the spinal dorsal horn. Moreover, the stress responsive physiological systems, genetic and psychological factors may modulate the experience of visceral pain. We also address some novel aetiological concepts in FGIDs, namely the gastrointestinal microbiota, connective tissue abnormalities and the gastrointestinal neuromuscular disorders. Firstly, the gastrointestinal microbiota is a diverse and dynamic ecosystem, that safeguards the host from external pathogens, aids in the metabolism of polysaccharides and lipids, modulates intestinal motility, in addition to modulating visceral perception. Secondly, connective tissue disorders, which traditionally have been considered to be confined largely to the musculoskeletal system, have an increasing evidence base demonstrating the presence of visceral manifestations. Since the sensorimotor apparatus of the GI tract is embedded within connective tissue it should not be surprising that such disorder may result in visceral pain and abnormal gut motility. Thirdly, gastrointestinal neuromuscular diseases refer to a heterogeneous group of disorders in which symptoms arise from impaired GI motor activity often manifesting as abnormal transit with or without radiological evidence of transient or persistent dilation of the viscera. Although a number of these are readily recognizable, such as achalasia or Hirschsprung's disease, the cause in a number of patients is not. An international working group has recently addressed this "gap", providing a comprehensive morphologically based diagnostic criteria. Conclusions/implications Although marked advances have been made in understanding the mechanisms that contribute to the development and maintenance of visceral pain, many interventions have failed to produce tangible improvement in patient outcomes. In the last part of this review we highlight an emerging approach that has allowed the definition and delineation of temporally stable visceral pain clusters, which may improve participant homogeneity in future studies, potentially facilitate stratification of treatment in FGID and lead to improvements in diagnostic criteria and outcomes.
背景与目的 慢性内脏痛在患有可识别器质性疾病的患者中很常见,在那些没有任何结构、生化或免疫异常的患者中也很常见,比如功能性胃肠病(FGIDs)患者。我们旨在对内脏痛觉感受所涉及的通路以及多种机制如何影响个体的内脏痛体验进行同步总结。方法 在本叙述性综述中,除了运用我们自身以及其他研究团队的经验和对近期研究进展的了解外,我们还通过详细检索Medline汇集了相关证据。结果 FGIDs是一组异质性疾病,其病因在很大程度上仍是个谜。FGIDs中慢性内脏痛发生和维持的相关假说是内脏高敏性概念。已经提出了一些外周和中枢机制来解释这一现象。在外周,炎症介质通过降低伤害性传入神经的转导阈值、诱导原本沉默的伤害感受器的表达和募集,从而激活并致敏伤害性传入神经,最终导致损伤部位的疼痛敏感性增加,即原发性痛觉过敏。在中枢,继发性痛觉过敏定义为解剖学上不同部位的疼痛敏感性增加,发生在脊髓背角水平。此外,应激反应生理系统、遗传和心理因素可能会调节内脏痛体验。我们还探讨了FGIDs中的一些新的病因学概念,即胃肠道微生物群、结缔组织异常和胃肠神经肌肉疾病。首先,胃肠道微生物群是一个多样且动态的生态系统,它保护宿主免受外部病原体侵害,有助于多糖和脂质的代谢,调节肠道蠕动,还能调节内脏感觉。其次,结缔组织疾病传统上主要被认为局限于肌肉骨骼系统,但越来越多的证据表明存在内脏表现。由于胃肠道的感觉运动装置嵌入结缔组织中,因此这种疾病可能导致内脏痛和肠道运动异常也就不足为奇了。第三,胃肠神经肌肉疾病是一组异质性疾病,其症状源于胃肠运动活动受损,常表现为转运异常,伴有或不伴有内脏短暂或持续扩张的影像学证据。虽然其中一些疾病很容易识别,如贲门失弛缓症或先天性巨结肠,但许多患者的病因并不明确。一个国际工作组最近解决了这一“空白”,提供了基于形态学的综合诊断标准。结论/启示 尽管在理解导致内脏痛发生和维持的机制方面取得了显著进展,但许多干预措施未能在患者预后方面产生切实改善。在本综述的最后部分,我们强调了一种新出现的方法,该方法能够定义和描绘时间上稳定的内脏痛集群,这可能会提高未来研究中参与者的同质性,潜在地促进FGID治疗的分层,并改善诊断标准和预后。
Scand J Pain. 2014-4-1
Br J Pain. 2013-2
Br Med Bull. 2009-7-19
Brain Behav Immun. 2010-11-20
Best Pract Res Clin Gastroenterol. 2002-12
J Med Life. 2019
Scand J Pain. 2017-10
Am J Physiol Gastrointest Liver Physiol. 2017-6-1
Nat Rev Rheumatol. 2024-11
Rev Assoc Med Bras (1992). 2023-6-2
Therap Adv Gastroenterol. 2023-3-3
Acta Clin Croat. 2021-12
Nat Rev Dis Primers. 2020-1-6