腕管综合征术中神经电生理检测与手术疗效评价的初步探讨

Preliminary observation of the relationship between intraoperative electrophysiologic testing and surgical outcome of carpal tunnel release

目的通过对腕管综合征术前、术中正中神经．拇短展肌复合肌肉动作电位（compound muscle action potential，CMAP）变化的观察，寻求检测手术效果的可靠指标和时机。方法对15例腕管综合征行腕管切开正中神经松解术的患者，分别于术前（臂丛神经阻滞麻醉后）、正中神经松解术毕松止血带后即刻及1、3、5、7min检测正中神经．拇短展肌CMAP潜伏期和波幅的动态变化，并与术前检测值进行统计学分析。结果正中神经松解术毕松止血带后即刻至5min，正中神经一拇短展肌CMAP的潜伏期和波幅随时间变化而有显著改变（P〈0．05），5min以后的变化差异无统计学意义（P〉0．05）。正中神经．拇短展肌CMAP的潜伏期比术前缩短，差异有统计学意义（P〈0．05），但波幅与术前相比差异有明显统计学意义（P〈0．01）。结论对腕管综合征行神经松解术后，拇短展肌CMAP的波幅比其潜伏期更能体现神经松解的疗效，而在松止血带5min后进行神经电生理检测来评价手术效果更为可靠。

Objective To explore a reliable predicator of surgical outcomes of carpal tunnel release （CTR） by exploring the changes of pre-and intraopemtive median nerve-abductor pollicis brevis compound muscle action potential （CMAP）. Methods Fifteen patients with carpal tunnel syndrome were involved in the study. Electrophysiologic examination was carried out to record CMAP of abductor pollicis brevis muscle at following moments： before CTR right after brachial plexus block, immediate after CTR and tourniquet release, 1 minute, 3 minutes, 5 minutes and 7 minutes after tourniquet release. Statistics analysis was done to compare these parameters with preoperative values. Results There were statistically significant changes in both amplitude and latency of the CMAP within 5 minutes after tourniquet release （ P 〈 0.05 ）, while not much difference was seen after 5 minutes. While both the latency and amplitude of CMAP were greatly improved （ P 〈 0.05）, the improvement of amplitude had more statistical significance （ P 〈 0.01 ）. Conclusion CMAP amplitude is a better predictor than CMAP latency to evaluate the effectiveness of median nerve decompression. It is more reliable to carry out electrophysiologic examination at least 5 minutes after tourniquet release.