Uchida Y, Sugioka Y
Department of Orthopedic Surgery, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Electromyogr Clin Neurophysiol. 1993 Jan-Feb;33(1):55-8.
We measured evoked mixed nerve action potentials (EMNAP) in the forearm segment of 108 hands as an indicator of retrograde degeneration in the carpal tunnel syndrome (CTS). This was made by recording at the elbow and stimulating the median nerve 4 cm proximal to the wrist crease. The amplitude of this EMNAP decreased in proportion to the prolongation of the motor terminal latency (MTL) or the decrease in the amplitude of the compound muscle action potential (CMAP) from the abductor pollicis brevis (APB) muscle. This suggests that retrograde degeneration progresses as the severity of CTS increases. This decrease was also in proportion to the decrease in the motor nerve conduction velocity (MNCV) in the forearm. Both MNCV in the forearm and EMNAP can indicate retrograde degeneration in CTS, but the MNCV cannot be measured when muscle atrophy is severe and the CMAP cannot be elicited. Therefore, we believe that EMNAP is a more useful measure of the retrograde changes in CTS.
我们测量了108只手前臂段的诱发混合神经动作电位（EMNAP），作为腕管综合征（CTS）中逆行性退变的指标。这是通过在肘部记录并在腕横纹近端4厘米处刺激正中神经来完成的。该EMNAP的振幅与运动终末潜伏期（MTL）的延长或拇短展肌（APB）复合肌肉动作电位（CMAP）振幅的降低成比例下降。这表明逆行性退变随着CTS严重程度的增加而进展。这种下降也与前臂运动神经传导速度（MNCV）的降低成比例。前臂的MNCV和EMNAP都可以指示CTS中的逆行性退变，但当肌肉萎缩严重且无法引出CMAP时，无法测量MNCV。因此，我们认为EMNAP是CTS中逆行性变化更有用的测量指标。
