1The Miami Project to Cure Paralysis, and Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida; and.
2Belford Center for Spinal Cord Injury, The Ohio State Neurological Institute, Department of Neurology, The Ohio State University, Columbus, Ohio.
J Neurosurg Spine. 2021 Nov 12;36(4):653-659. doi: 10.3171/2021.7.SPINE21546. Print 2022 Apr 1.
The corticospinal tract (CST) is the preeminent voluntary motor pathway that controls human movements. Consequently, long-standing interest has focused on CST location and function in order to understand both loss and recovery of neurological function after incomplete cervical spinal cord injury, such as traumatic central cord syndrome. The hallmark clinical finding is paresis of the hands and upper-extremity function with retention of lower-extremity movements, which has been attributed to injury and the sparing of specific CST fibers. In contrast to historical concepts that proposed somatotopic (laminar) CST organization, the current narrative summarizes the accumulated evidence that 1) there is no somatotopic organization of the corticospinal tract within the spinal cord in humans and 2) the CST is critically important for hand function. The evidence includes data from 1) tract-tracing studies of the central nervous system and in vivo MRI studies of both humans and nonhuman primates, 2) selective ablative studies of the CST in primates, 3) evolutionary assessments of the CST in mammals, and 4) neuropathological examinations of patients after incomplete cervical spinal cord injury involving the CST and prominent arm and hand dysfunction. Acute traumatic central cord syndrome is characterized by prominent upper-extremity dysfunction, which has been falsely predicated on pinpoint injury to an assumed CST layer that specifically innervates the hand muscles. Given the evidence surveyed herein, the pathophysiological mechanism is most likely related to diffuse injury to the CST that plays a critically important role in hand function.
皮质脊髓束（CST）是控制人类运动的首要自主运动通路。因此，长期以来，人们一直关注 CST 的位置和功能，以了解不完全性颈脊髓损伤（如创伤性中央索综合征）后神经功能的丧失和恢复。标志性的临床发现是手部和上肢功能无力，下肢运动保留，这归因于损伤和特定 CST 纤维的保留。与提出躯体感觉（层状）CST 组织的历史概念相反，目前的叙述总结了累积的证据，即 1）在人类脊髓中没有 CST 的躯体感觉组织，2）CST 对手部功能至关重要。证据包括：1）中枢神经系统的束追踪研究和人类和非人类灵长类动物的活体 MRI 研究，2）灵长类动物 CST 的选择性消融研究，3）哺乳动物 CST 的进化评估，以及 4）涉及 CST 和明显手臂和手部功能障碍的不完全颈脊髓损伤患者的神经病理学检查。急性创伤性中央索综合征的特征是明显的上肢功能障碍，这是基于对手部肌肉进行特定神经支配的 CST 层的点状损伤的错误预测。鉴于本文综述的证据，病理生理学机制很可能与 CST 的弥漫性损伤有关，CST 在手部功能中起着至关重要的作用。
