多灶性运动神经病电生理诊断的初步研究

Electrophysiological Diagnosis of Multifocal Motor Neuropathy

目的探讨多灶性运动神经病(MIVEN)的电生理诊断特点。方法对6例临床诊断为MMN的患者进行电生理检查,MCV测定采用自近端至远端分段刺激,记录各段刺激引发CMAP的波幅、时限、面积,并判定CB和TD。结果6例患者所有受累运动神经至少有一条出现CB,正中神经和尺神经最易出现,其中腕至肘、腋至Erb′点为好发部位。其它脱鞘样电生理表现也可常见,部分神经可出现轻度轴索样改变。结论 MMN是一种脱鞘为主的周围神经病,表现为运动神经的传导阻滞,CB为MMN特征性的诊断依据。

Objective To study the electrophysiological characteristic of multifocal motor neuropathy(MMN). Methods Detailed electrophysiologic studies were performed on 6 cases with clinically defined MMN. The items included motor conduction velocity (MCV), sensory conduction velocity (SCV) and F waves. MCV studies were done segmentally by stimulating the nerve distally as well as proximally and recording compound muscle action potentials (CMAP). The values obtained from the distal and proximal ends were compared to ascertain the presence of conduction block (CB) and temporal dispersion (TD). Results All 6 patients showed CB in at least one motor nerve, CB was detected frequently in median and ulnar nerves in the wrist to elbow and axilla to Erb's point segments. In addition, other features including focal slowing of conduction velocity, TD and abnormal F wave responses invariably occurred in nerves of MMN patients. Conclusion The study demonstrated that MMN is a demyelinating motor neuropathy with highly characteristic electrophysiological features, with CB in motor nerves as an important electrodiagnostic hallmark, which is consistent with pathologic results.