Chronic pain after spine surgery(CPSS)is a complex disorder characterized by multifactorial pathogenesis that occurs in 8%–40%of patients undergoing lumbar spine surgery.We aimed to develop a rat model that mimics cl...Chronic pain after spine surgery(CPSS)is a complex disorder characterized by multifactorial pathogenesis that occurs in 8%–40%of patients undergoing lumbar spine surgery.We aimed to develop a rat model that mimics clinical CPSS conditions by taking two sequential surgical procedures.Step 1:A plastic rod was inserted into the left L5 intervertebral foramen to produce a steady compression on the dorsal root ganglion(DRG)and the spinal nerve,a common cause of low back pain(LBP).Step 2:The rod was removed after 7 days when rats exhibited mechanical and heat hypersensitivity in the ipsilateral hindpaw,followed by a full L5 laminectomy to mimic spine decompression surgery in LBP patients.The retention of the rod induced a prolonged LBP-like behavior but was quickly resolved after rod removal without laminectomy.However,rats that received laminectomy after rod removal developed heightened mechanical and heat sensitivity in the hindpaw,impaired gait,and reduced spontaneous exploration activity,indicating CPSS.Patch clamp recording revealed a significant augmentation in the intrinsic excitability of smalldiameter DRG neurons in CPSS rats.Administration of Dermorphin[D-Arg2,Lys4](1–4)amide(DALDA,5mg/kg,i.p.),a peripherally acting mu-opioid receptor(MOR)-preferred agonist,attenuated pain hypersensitivity,capsaicin-induced[Ca^(2+)]i rising and the increased intrinsic excitability of DRG neurons from CPSS rats.Our findings suggest that this new model,which mirrors the nature of CPSS developed in patients,may be useful for future studies of the underlying mechanisms.展开更多
In addition to restoration of bladder, bowel, and motor functions, alleviating the accompanying debilitating pain is equally important for improving the quality of life of patients with spinal cord injury(SCI). Curren...In addition to restoration of bladder, bowel, and motor functions, alleviating the accompanying debilitating pain is equally important for improving the quality of life of patients with spinal cord injury(SCI). Currently,however, the treatment of chronic pain after SCI remains a largely unmet need. Electrical spinal cord stimulation(SCS) has been used to manage a variety of chronic pain conditions that are refractory to pharmacotherapy. Yet, its efficacy, benefit profiles, and mechanisms of action in SCI pain remain elusive, due to limited research, methodological weaknesses in previous clinical studies, and a lack of mechanistic exploration of SCS for SCI pain control. We aim to review recent studies and outline the therapeutic potential of different SCS paradigms for traumatic SCI pain. We begin with an overview of its manifestations,classification, potential underlying etiology, and currentchallenges for its treatment. The clinical evidence for using SCS in SCI pain is then reviewed. Finally, future perspectives of pre-clinical research and clinical study of SCS for SCI pain treatment are discussed.展开更多
The field of research on pain originating from various bone diseases is expanding rapidly, with new mechanisms and targets asserting both peripheral and central sites of action. The scope of research is broadening fro...The field of research on pain originating from various bone diseases is expanding rapidly, with new mechanisms and targets asserting both peripheral and central sites of action. The scope of research is broadening from bone biology to neuroscience,neuroendocrinology, and immunology. In particular, the roles of primary sensory neurons and non-neuronal cells in the peripheral tissues as important targets for bone pain treatment are under extensive investigation in both pre-clinical and clinical settings. An understanding of the peripheral mechanisms underlying pain conditions associated with various bone diseases will aid in the appropriate application and development of optimal strategies for not only managing bone pain symptoms but also improving bone repairing and remodeling, which potentially cures the underlying etiology for long-term functional recovery. In this review, we focus on advances in important preclinical studies of significant bone pain conditions in the past 5 years that indicated new peripheral neuronal and non-neuronal mechanisms, novel targets for potential clinical interventions, and future directions of research.展开更多
基金supported by the Neurosurgery Pain Research Institute at Johns Hopkins University and by the Lehner Family Foundation.
文摘Chronic pain after spine surgery(CPSS)is a complex disorder characterized by multifactorial pathogenesis that occurs in 8%–40%of patients undergoing lumbar spine surgery.We aimed to develop a rat model that mimics clinical CPSS conditions by taking two sequential surgical procedures.Step 1:A plastic rod was inserted into the left L5 intervertebral foramen to produce a steady compression on the dorsal root ganglion(DRG)and the spinal nerve,a common cause of low back pain(LBP).Step 2:The rod was removed after 7 days when rats exhibited mechanical and heat hypersensitivity in the ipsilateral hindpaw,followed by a full L5 laminectomy to mimic spine decompression surgery in LBP patients.The retention of the rod induced a prolonged LBP-like behavior but was quickly resolved after rod removal without laminectomy.However,rats that received laminectomy after rod removal developed heightened mechanical and heat sensitivity in the hindpaw,impaired gait,and reduced spontaneous exploration activity,indicating CPSS.Patch clamp recording revealed a significant augmentation in the intrinsic excitability of smalldiameter DRG neurons in CPSS rats.Administration of Dermorphin[D-Arg2,Lys4](1–4)amide(DALDA,5mg/kg,i.p.),a peripherally acting mu-opioid receptor(MOR)-preferred agonist,attenuated pain hypersensitivity,capsaicin-induced[Ca^(2+)]i rising and the increased intrinsic excitability of DRG neurons from CPSS rats.Our findings suggest that this new model,which mirrors the nature of CPSS developed in patients,may be useful for future studies of the underlying mechanisms.
基金supported by grants from the National Institutes of Health, Bethesda, MD (R01NS70814 and R21NS99879 to YG)
文摘In addition to restoration of bladder, bowel, and motor functions, alleviating the accompanying debilitating pain is equally important for improving the quality of life of patients with spinal cord injury(SCI). Currently,however, the treatment of chronic pain after SCI remains a largely unmet need. Electrical spinal cord stimulation(SCS) has been used to manage a variety of chronic pain conditions that are refractory to pharmacotherapy. Yet, its efficacy, benefit profiles, and mechanisms of action in SCI pain remain elusive, due to limited research, methodological weaknesses in previous clinical studies, and a lack of mechanistic exploration of SCS for SCI pain control. We aim to review recent studies and outline the therapeutic potential of different SCS paradigms for traumatic SCI pain. We begin with an overview of its manifestations,classification, potential underlying etiology, and currentchallenges for its treatment. The clinical evidence for using SCS in SCI pain is then reviewed. Finally, future perspectives of pre-clinical research and clinical study of SCS for SCI pain treatment are discussed.
文摘The field of research on pain originating from various bone diseases is expanding rapidly, with new mechanisms and targets asserting both peripheral and central sites of action. The scope of research is broadening from bone biology to neuroscience,neuroendocrinology, and immunology. In particular, the roles of primary sensory neurons and non-neuronal cells in the peripheral tissues as important targets for bone pain treatment are under extensive investigation in both pre-clinical and clinical settings. An understanding of the peripheral mechanisms underlying pain conditions associated with various bone diseases will aid in the appropriate application and development of optimal strategies for not only managing bone pain symptoms but also improving bone repairing and remodeling, which potentially cures the underlying etiology for long-term functional recovery. In this review, we focus on advances in important preclinical studies of significant bone pain conditions in the past 5 years that indicated new peripheral neuronal and non-neuronal mechanisms, novel targets for potential clinical interventions, and future directions of research.
