Sedal L, Ghabriel M N, He F, Allt G, Le Quesne P M, Harrison M J
J Neurol Sci. 1983 Aug;60(2):293-306. doi: 10.1016/0022-510x(83)90070-9.
The reliability of the electrophysiological criterion of conduction block in determining the presence of focal demyelination in a peripheral nerve has been studied in an animal model. Demyelination was produced in the rat tibial nerve by one or two closely spaced microinjections of lysophosphatidylcholine (LPC). Histological and electrophysiological data were obtained on the acute lesion (up to 6 days), and during recovery (up to 11 weeks). Single LPC injections produced a lesion of very variable severity. Double injections more reliably produced a severe lesion with marked conduction block. Slight axonal damage was occasionally seen in nerves showing severe demyelination. The ratio of amplitude of muscle action potentials evoked by stimuli proximal and distal to the sites of nerve injection was calculated to detect the development of conduction block. The post injection ratio was more than 2 standard deviations below the control mean in 86% of nerves showing signs of demyelination. No control saline injected nerves showed such evidence of conduction block. The severity of the electrophysiological abnormality did not prove a reliable indicator of the severity of the histological lesion, however. The possible reasons for this variability are discussed and it is argued that caution should be exercised when interpreting this particular electrophysiological finding in clinical practice.
在一个动物模型中，研究了传导阻滞的电生理标准在确定周围神经局灶性脱髓鞘存在方面的可靠性。通过一两次紧密间隔的微量注射溶血磷脂酰胆碱（LPC）在大鼠胫神经中产生脱髓鞘。在急性损伤期（长达6天）和恢复期间（长达11周）获取了组织学和电生理数据。单次LPC注射产生的损伤严重程度差异很大。两次注射更可靠地产生了伴有明显传导阻滞的严重损伤。在显示严重脱髓鞘的神经中偶尔可见轻微的轴突损伤。计算神经注射部位近端和远端刺激诱发的肌肉动作电位幅度之比，以检测传导阻滞的发展。在86%显示脱髓鞘迹象的神经中，注射后比值比对照平均值低超过2个标准差。注射对照生理盐水的神经未显示出这种传导阻滞的证据。然而，电生理异常的严重程度并不是组织学损伤严重程度的可靠指标。讨论了这种变异性的可能原因，并认为在临床实践中解释这一特定的电生理发现时应谨慎。
