正中神经压迫试验对腕管综合征神经传导速度的影响

目的比较正中神经压迫试验对腕管综合征（carpal tunnel syndrome,CTS）患者正中神经传导速度的影响。方法设置CTS组和对照组两个组别,共29例受试者纳入研究。CTS组为14例CTS患者,对照组为15例健康受试者。神经传导速度测定包括正中神经和尺神经的感觉传导末端潜伏期（distal sensory latency,DSL）、感觉神经动作电位（sensory nerve action potential,SNAP）、跨腕关节感觉传导速度（sensory conduction velocity,SCV）、运动传导末端潜伏期（distal motor latency,DML）及复合肌肉动作电位（compound muscle action potential,CMAP）。先测感觉传导,再测运动传导。正中神经压迫试验5min后再次测量上述指标。结果正中神经压迫试验前后电生理检查考虑诊断CTS分别为22侧和24侧。压迫正中神经后,CTS组正中神经DSL较压迫前显著延长（P〈0.05）。CTS组尺神经和对照组正中神经及尺神经的各参数在压迫前后均无显著改变（P〉0.05）。与对照组相比,在压迫试验前后CTS组的正中神经DSL和DML均明显延长（P〈0.05）,尺神经DSL和DML均无显著改变（P〉0.05）。结论正中神经压迫试验5min能使CTS患者正中神经的感觉传导末端潜伏时明显延长,有助于提高神经传导测定对早期CTS的诊断率。

Effect of Median Nerve Compression Test on the Nerve Conduction Speed in Carpal Tunnel Syndrome

Objective To determine the effect of median nerve compression on median nerve conduction speed in patients with carpal tunnel syndrome（CTS）.Methods In this case-control study,29 subjects were enrolled.CTS group included 14 patients（22 hands） with CTS confirmed by electrodiagnostic studies,while the control group included 15 healthy subjects（30 hands）.The across wrist nerve conduction of median and ulnar nerve was measured when the wrist was in neutral position.Measured parameters included distal sensory latency（DSL）,sensory nerve action potential（SNAP）,sensory conduction velocity（SCV）,distal motor latency（DML） and compound muscle action potential（CMAP）.Sensory nerve conductions were tested first,and then the motor nerve conduction.The patients were asked to perform the median nerve compression test by flexing elbows,pronating forearm and pushing the dorsal surfaces of both hands together into maximum wrist flexion for 5 minutes.Then the above parameters were measured again.Results By electrodiagnostic studies,22 hands and 24 bands were diagnosed with CTS before and after the median nerve compression test,respectively.After the compression test,the median nerve DSL were significantly prolonged in CTS group（P0.05） but no significant differences were found in the median nerve DML（P0.05）.The parameters of ulnar nerve in group CTS and median nerve and ulnar nerve in control group failed to show any significant change（P0.05）.The CTS group had longer median nerve DSL and DML than the control groups（P0.05）,but the differences in ulnar nerve DSL and DML were not significantly between the two groups.Conclusion A 5-minute median nerve compression test may make the median nerve DSL prolonged and may be a helpful diagnosis of early CTS.