Houle John D, Tessler Alan
Department of Anatomy and Neurobiology, University of Arkansas for Medical Science, Little Rock, AR 72205, USA.
Exp Neurol. 2003 Aug;182(2):247-60. doi: 10.1016/s0014-4886(03)00029-3.
Advances in medical and rehabilitative care now allow the 10-12,000 individuals who suffer spinal cord injuries each year in the United States to lead productive lives of nearly normal life expectancy, so that the numbers of those with chronic injuries will approximate 300,000 at the end of the next decade. This signals an urgent need for new treatments that will improve repair and recovery after longstanding injuries. In the present report we consider the characteristics of the chronically injured spinal cord that make it an even more challenging setting in which to elicit regeneration than the acutely injured spinal cord and review the treatments that have been designed to enhance axon growth. When applied in the first 2 weeks after experimental spinal cord injury, transplants, usually in combination with supplementary neurotrophic factors, and possibly modifications of the inhibitory central nervous system environment, have produced limited long-distance axon regeneration and behavioral recovery. When applied to injuries older than 4 weeks, the same treatments have almost invariably failed to overcome the obstacles posed by the neurons' diminished capacity for regeneration and by the increasing hostility to growth of the terrain at and beyond the injury site. Novel treatments that have stimulated regeneration after acute injuries have not yet been applied to chronic injuries. A therapeutic strategy that combines rehabilitation training and pharmacological modulation of neurotransmitters appears to be a particularly promising approach to increasing recovery after longstanding injury. Identifying patients with no hope of useful recovery in the early days after injury will allow these treatments to be administered as early as possible.
医学和康复护理的进步，如今已使美国每年10000至12000名脊髓损伤患者能够过上接近正常预期寿命的有意义生活，因此到下一个十年末，慢性损伤患者数量将接近30万。这表明迫切需要新的治疗方法，以改善长期损伤后的修复和恢复情况。在本报告中，我们探讨了慢性脊髓损伤的特点，这些特点使其比急性脊髓损伤更具挑战性，难以诱导再生，并回顾了旨在促进轴突生长的治疗方法。在实验性脊髓损伤后的前两周内应用时，移植（通常与补充神经营养因子联合使用）以及可能对抑制性中枢神经系统环境的改变，已产生了有限的长距离轴突再生和行为恢复。当应用于4周以上的损伤时，同样的治疗方法几乎总是无法克服神经元再生能力下降以及损伤部位及其周围对生长的敌意增加所带来的障碍。在急性损伤后刺激再生的新治疗方法尚未应用于慢性损伤。将康复训练与神经递质的药理学调节相结合的治疗策略，似乎是一种特别有前景的方法，可促进长期损伤后的恢复。在损伤后的早期识别出没有希望获得有效恢复的患者，将使这些治疗能够尽早实施。
