Departments of Anesthesiology and Critical Care Medicine and Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, Baltimore, MD 21029, USA.
BMJ. 2014 Feb 5;348:f7656. doi: 10.1136/bmj.f7656.
Neuropathic pain can develop after nerve injury, when deleterious changes occur in injured neurons and along nociceptive and descending modulatory pathways in the central nervous system. The myriad neurotransmitters and other substances involved in the development and maintenance of neuropathic pain also play a part in other neurobiological disorders. This might partly explain the high comorbidity rates for chronic pain, sleep disorders, and psychological conditions such as depression, and why drugs that are effective for one condition may benefit others. Neuropathic pain can be distinguished from non-neuropathic pain by two factors. Firstly, in neuropathic pain there is no transduction (conversion of a nociceptive stimulus into an electrical impulse). Secondly, the prognosis is worse: injury to major nerves is more likely than injury to non-nervous tissue to result in chronic pain. In addition, neuropathic pain tends to be more refractory than non-neuropathic pain to conventional analgesics, such as non-steroidal anti-inflammatory drugs and opioids. However, because of the considerable overlap between neuropathic and nociceptive pain in terms of mechanisms and treatment modalities, it might be more constructive to view these entities as different points on the same continuum. This review focuses on the mechanisms of neuropathic pain, with special emphasis on clinical implications.
神经病理性疼痛可在神经损伤后发生，此时损伤神经元以及中枢神经系统中的伤害性和下行调制通路上发生有害变化。在神经病理性疼痛的发生和维持中涉及的众多神经递质和其他物质也在其他神经生物学疾病中发挥作用。这可能部分解释了慢性疼痛、睡眠障碍和心理状况（如抑郁）的高共病率，以及为什么对一种疾病有效的药物可能对其他疾病有益。神经病理性疼痛可通过两个因素与非神经病理性疼痛区分开来。首先，在神经病理性疼痛中没有换能（将伤害性刺激转换为电脉冲）。其次，预后更差：大神经的损伤比非神经组织的损伤更有可能导致慢性疼痛。此外，与非甾体抗炎药和阿片类药物等传统镇痛药相比，神经病理性疼痛往往更难治疗。然而，由于在机制和治疗方式方面，神经病理性疼痛和伤害性疼痛之间存在相当大的重叠，因此将这些实体视为同一连续体上的不同点可能更具建设性。本篇综述重点介绍神经病理性疼痛的机制，并特别强调其临床意义。
