Nukada H, Pollock M, Allpress S
Brain. 1981 Dec;104(Pt 4):779-811. doi: 10.1093/brain/104.4.779.
Focal non-freezing injury to rat sciatic nerve resulted in nerve conduction block and cessation of axoplasmic transport. Rats showed early functional recovery but subsequently developed a slowly progressive sciatic nerve paralysis. Horseradish peroxidase studies revealed prominent nerve oedema with early enhanced pinocytosis and later, passive leakage through damaged endoneurial capillaries. Detailed microscopy indicated a striking selective vulnerability to cold based on nerve fibre diameter. Unmyelinated fibres were spared while large myelinated nerve fibres showed severe axonal degeneration. Paranodal and segmental demyelination were infrequent findings and may have resulted from early axonal swelling. Possible pathogenic mechanisms to explain the degeneration of myelinated fibres in hypothermic injury are discussed. It is concluded that the gradient of clinical severity seen in limb hypothermic injuries has a pathological correlate in peripheral nerve.
大鼠坐骨神经局灶性非冻结性损伤导致神经传导阻滞和轴浆运输停止。大鼠早期功能恢复，但随后出现缓慢进展的坐骨神经麻痹。辣根过氧化物酶研究显示，早期有明显的神经水肿，伴有胞饮作用增强，后期则通过受损的神经内膜毛细血管出现被动渗漏。详细的显微镜检查表明，根据神经纤维直径，对寒冷存在显著的选择性易损性。无髓纤维未受影响，而大的有髓神经纤维则出现严重的轴突变性。结旁和节段性脱髓鞘是少见的发现，可能是早期轴突肿胀所致。文中讨论了解释低温损伤中有髓纤维变性的可能致病机制。得出的结论是，肢体低温损伤中所见的临床严重程度梯度在外周神经中有病理相关性。
