Bramlett Helen M, Dietrich W Dalton
Department of Neurological Surgery, Neurotrauma Research Center, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Miami, FL 33136, USA.
Prog Brain Res. 2007;161:125-41. doi: 10.1016/S0079-6123(06)61009-1.
The pathophysiology of brain and spinal cord injury (SCI) is complex and involves multiple injury mechanisms that are spatially and temporally specific. It is now appreciated that many of these injury mechanisms remain active days to weeks after a primary insult. Long-term survival studies in clinically relevant experimental studies have documented the structural changes that continue at the level of the insult as well as in remote brain structures. After traumatic brain injury (TBI), progressive atrophy of both gray and white matter structures continues up to 1 year post-trauma. Progressive changes may therefore underlie some of the long-term functional deficits observed in this patient population. After SCI, similar features of progressive injury are observed including delayed cell death of neurons and oligodendrocytes, axonal demyelination of intact fiber tracts and retrograde tract degeneration. SCI also leads to supraspinal changes in cell survival and remote brain circuitry. The progressive changes in multiple structures after brain and SCI are important because of their potential consequences on chronic or developing neurological deficits associated with these insults. In addition, the better understanding of these injury cascades may one day allow new treatments to be developed that can inhibit these responses to injury and hopefully promote recovery. This chapter summarizes some of the recent data regarding progressive damage after CNS trauma and mechanisms underlying these changes.
脑和脊髓损伤（SCI）的病理生理学很复杂，涉及多种在空间和时间上具有特异性的损伤机制。现在人们认识到，许多这些损伤机制在原发性损伤后的数天至数周内仍处于活跃状态。临床相关实验研究中的长期存活研究记录了损伤部位以及远处脑结构持续发生的结构变化。创伤性脑损伤（TBI）后，灰质和白质结构的渐进性萎缩会持续到创伤后1年。因此，渐进性变化可能是该患者群体中观察到的一些长期功能缺陷的基础。SCI后，也观察到类似的渐进性损伤特征，包括神经元和少突胶质细胞的延迟性细胞死亡、完整纤维束的轴突脱髓鞘以及逆行束变性。SCI还会导致脊髓以上部位的细胞存活和远处脑回路发生变化。脑和SCI后多个结构的渐进性变化很重要，因为它们可能对与这些损伤相关的慢性或进展性神经功能缺损产生潜在影响。此外，对这些损伤级联反应的更好理解可能有朝一日会促使开发出新的治疗方法，能够抑制对损伤的这些反应，并有望促进恢复。本章总结了一些关于中枢神经系统创伤后渐进性损伤以及这些变化背后机制的最新数据。
