神经根牵拉损伤机制的研究进展

摘要

背景：生理状态下神经根会随肢体和脊柱运动而受到牵拉，但是病理状态下神经根出现牵拉损伤机制以及引起损伤后神经功能异常的机制尚不清楚。　　目的：综述不同状态下神经根牵拉损伤的原因，并从生物力学、病理学和神经生理学层面分析影响神经功能的机制。　　方法：由第一作者检索1990至2012年Pubmed数据库有关神经根损伤研究和神经牵拉损伤研究方面的文献，英文检索词为“nerve root, nerve, stretch injury”，检索文献量总计391篇。纳入神经根解剖学研究和生物力学研究，神经根牵拉损伤后病理学研究和神经生理学研究，共44篇进入结果分析。　　结果与结论：随四肢或脊柱的运动，神经根会承受一定的牵拉作用。而当发生病变或外伤后，引起神经根病理性牵拉出现神经功能异常的症状。神经根容易受牵拉作用的影响与其解剖和组织结构有关。牵拉的机械损伤机制包括外周机制(外周神经传导应力)和中枢机制(脊髓内容物发生位移)。病理学研究认为由于神经根内缺少淋巴系统，当损伤发生后，渗出的血清蛋白清除困难最终引起局部纤维化。纤维化会造成神经根缺血，影响神经功能并且使神经根生物力学特性发生改变。神经根损伤还会造成内部神经轴突发生原发性和继发性损伤，这也是引起损伤后神经功能异常的重要原因。%BACKGROUND:Under physiological conditions, nerve roots can move along with the movement of limbs and spine. However, the mechanisms of nerve root stretch injury under physiological conditions and the neurological dysfunction after injury are unclear. OBJECTIVE:To review the reason of nerve root stretch injury, and to analyze the mechanism of nerve function from biomechanics, pathology and neurophysiology. METHODS:A computer-based online search of PubMed database was undertaken by the first author to identify the articles related to the research of nerve root injury and nerve stretch injury between 1990 and 2012, with the key words of“nerve root, nerve, stretch injury”. A total of 391 articles were screened out. The articles on the anatomy and biomechanics research of nerve root were included, as wel as the pathology and neurophysiology research after nerve root stretch injury. Final y, 44 articles were included for review. RESULTS AND CONCLUSION:Nerve root can be stretched along with limbs and spine movement. However, diseases or trauma may cause pathological nerve root stretch, and thus leading neurological dysfunction. The nerve root is often influenced stretch because of its anatomical and tissue structure. Mechanical injury mechanism of stretch composes of peripheral (peripheral nerve conduction stress) and central mechanism (displacement of spinal cord content). Pathological studies found that the local fibrosis is caused by the extracted serum protein that difficult to remove after injury, and this is because of the shortage of lymphatic system in nerve roots. Fibrosis can cause nerve root ischemia, affect the nerve function, and change the biomechanical properties of nerve root. Nerve root injury can cause primary and secondary injury of internal axons, and this is the main reason for neurological dysfunction after injury.