Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, UCL, Queen Square, London WC1N 3BG, UK.
Brain. 2011 Jun;134(Pt 6):1610-22. doi: 10.1093/brain/awr093. Epub 2011 May 17.
The impact of traumatic spinal cord injury on structural integrity, cortical reorganization and ensuing disability is variable and may depend on a dynamic interaction between the severity of local damage and the capacity of the brain for plastic reorganization. We investigated trauma-induced anatomical changes in the spinal cord and brain, and explored their relationship to functional changes in sensorimotor cortex. Structural changes were assessed using cross-sectional cord area, voxel-based morphometry and voxel-based cortical thickness of T1-weighted images in 10 subjects with cervical spinal cord injury and 16 controls. Cortical activation in response to right-sided (i) handgrip; and (ii) median and tibial nerve stimulation were assessed using functional magnetic resonance imaging. Regression analyses explored associations between cord area, grey and white matter volume, cortical activations and thickness, and disability. Subjects with spinal cord injury had impaired upper and lower limb function bilaterally, a 30% reduced cord area, smaller white matter volume in the pyramids and left cerebellar peduncle, and smaller grey matter volume and cortical thinning in the leg area of the primary motor and sensory cortex compared with controls. Functional magnetic resonance imaging revealed increased activation in the left primary motor cortex leg area during handgrip and the left primary sensory cortex face area during median nerve stimulation in subjects with spinal cord injury compared with controls, but no increased activation following tibial nerve stimulation. A smaller cervical cord area was associated with impaired upper limb function and increased activations with handgrip and median nerve stimulation, but reduced activations with tibial nerve stimulation. Increased sensory deficits were associated with increased activations in the left primary sensory cortex face area due to median nerve stimulation. In conclusion, spinal cord injury leads to cord atrophy, cortical atrophy of primary motor and sensory cortex, and cortical reorganization of the sensorimotor system. The degree of cortical reorganization is predicted by spinal atrophy and is associated with significant disability.
创伤性脊髓损伤对结构完整性、皮质重组以及随之而来的残疾的影响是可变的，可能取决于局部损伤的严重程度和大脑的可塑性重组能力之间的动态相互作用。我们研究了脊髓和大脑的创伤性解剖结构变化，并探讨了它们与感觉运动皮层功能变化的关系。在 10 名颈脊髓损伤患者和 16 名对照者中，使用 T1 加权图像的脊髓横截面积、基于体素的形态测量学和基于体素的皮质厚度来评估结构变化。使用功能磁共振成像评估对右侧（i）手抓握；以及（ii）正中神经和胫后神经刺激的皮质激活。回归分析探讨了脊髓面积、灰质和白质体积、皮质激活和厚度以及残疾之间的关联。脊髓损伤患者双侧上肢和下肢功能受损，脊髓面积减少 30%，锥体和左侧小脑脚的白质体积减小，初级运动和感觉皮层腿部的灰质体积和皮质变薄。功能磁共振成像显示，与对照组相比，脊髓损伤患者在手抓握时左侧初级运动皮层腿部区域和正中神经刺激时左侧初级感觉皮层面部区域的激活增加，但胫后神经刺激时无激活增加。颈脊髓面积较小与上肢功能障碍有关，与手抓握和正中神经刺激相关的激活增加，但与胫后神经刺激相关的激活减少。感觉缺陷增加与由于正中神经刺激导致左侧初级感觉皮层面部区域的激活增加有关。总之，脊髓损伤导致脊髓萎缩、初级运动和感觉皮层皮质萎缩以及感觉运动系统的皮质重组。皮质重组的程度由脊髓萎缩预测，并与显著的残疾有关。
