臂丛损伤健侧C7神经移位术后大脑运动皮质远期功能重组

目的:运用功能磁共振成像方法研究臂丛根性撕脱伤并行健侧C7神经移位术后大脑运动功能的远期变化。方法:8例经临床检查和手术证实一侧全臂丛根性撕脱伤男性患者(健侧C7术后两年以上)以及9名健康男性被试接受磁共振扫描。运动任务为单侧手的抓握运动。结果:健康对照组单侧手运动时所有被试均主要激活对侧初级运动区和辅助运动区而且偏侧化系数均大于0。组分析结果同样显示单侧手运动主要激活对侧大脑半球运动脑区。患者患肢运动激活双侧运动皮质,但偏侧化系数大于0,提示患肢运动主要激活对侧运动皮质(M1和SMA)。5例右侧臂丛损伤患者组分析结果显示患肢运动主要激活对侧运动皮质。3例左侧臂丛损伤患者单个被试偏侧化系数分析及激活图像显示患肢运动主要激活脑区位于对侧运动皮质。结论:健侧C7神经移位术后,大脑会试图利用原躯体运动区对患肢运动进行控制。

Long-range Cerebral Plasticity of the Human Brain after Contralateral C7 Nerve Transfer

Purpose: To assess the characteristics of long-range cerebral plasticity of the human brain cortex after the seventh contralateral cervical nerve transfer by using functional MRI(fMRI).Methods: Nine healthy male volunteers and 8 male patients with total brachial plexus traction injuries(more than 2 years after contralateral C7 nerve transfer) were studied by using fMRI.Functional brain images were acquired under the condition of hand grasping of unilateral hand.Results: All healthy volunteers’ unilateral hand movement generated strong signal change in the contralateral sensorimotor cortex and the laterality index of every healthy control was positive.Group analysis of the control group showed the same result as single subject analysis.Movement of the affected hand of patient was associated with a bilateral network activation,but the laterality index was positive,which implied that the main activated areas were located in the contralateral cortex.Group analysis of the 5 right brachial plexus injury patients and single subject analysis of the 3 left brachial plexus injury patients revealed the same results.Conclusion: The brain may try to restore the control of an injured limb to its original cortex after the seventh contralateral cervical nerve transfer.