Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA ; Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China ; Department of Orthopedic Surgery, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.
Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, USA ; Department of Orthopedic Surgery, Wake Forest School of Medicine, Winston-Salem, NC, USA.
Neural Regen Res. 2014 Oct 15;9(20):1796-809. doi: 10.4103/1673-5374.143424.
The neuromuscular junction becomes progressively less receptive to regenerating axons if nerve repair is delayed for a long period of time. It is difficult to ascertain the denervated muscle's residual receptivity by time alone. Other sensitive markers that closely correlate with the extent of denervation should be found. After a denervated muscle develops a fibrillation potential, muscle fiber conduction velocity, muscle fiber diameter, muscle wet weight, and maximal isometric force all decrease; remodeling increases neuromuscular junction fragmentation and plantar area, and expression of myogenesis-related genes is initially up-regulated and then down-regulated. All these changes correlate with both the time course and degree of denervation. The nature and time course of these denervation changes in muscle are reviewed from the literature to explore their roles in assessing both the degree of detrimental changes and the potential success of a nerve repair. Fibrillation potential amplitude, muscle fiber conduction velocity, muscle fiber diameter, mRNA expression levels of myogenic regulatory factors and nicotinic acetylcholine receptor could all reflect the severity and length of denervation and the receptiveness of denervated muscle to regenerating axons, which could possibly offer an important clue for surgical choices and predict the outcomes of delayed nerve repair.
如果神经修复延迟很长时间，神经肌肉接头对再生轴突的接受能力会逐渐降低。仅通过时间很难确定去神经肌肉的剩余接受能力。应该找到其他与去神经支配程度密切相关的敏感标志物。去神经支配的肌肉出现纤颤电位后，肌肉纤维传导速度、肌纤维直径、肌肉湿重和最大等长力均降低；重塑增加神经肌肉接头的碎片化和足底面积，肌发生相关基因的表达最初上调，然后下调。所有这些变化都与去神经支配的时间过程和程度相关。本文从文献中综述了肌肉去神经支配变化的性质和时间过程，以探讨其在评估神经损伤的严重程度和神经修复的潜在成功中的作用。纤颤电位幅度、肌纤维传导速度、肌纤维直径、肌生成调节因子和烟碱型乙酰胆碱受体的 mRNA 表达水平均可反映去神经支配的严重程度和长度以及去神经支配肌肉对再生轴突的接受能力，这可能为手术选择提供重要线索，并预测延迟神经修复的结果。
