Havton Leif A, Hotson John R, Kellerth Jan-Olof
Department of Neurology and Brain Research Institute, David Geffen School of Medicine at UCLA, University of California-Los Angeles, 710 Westwood Plaza, Los Angeles, CA 90095-1769, USA.
Clin Neurophysiol. 2007 Apr;118(4):781-5. doi: 10.1016/j.clinph.2006.12.011. Epub 2007 Feb 16.
Median nerve entrapment neuropathy at the wrist can be accompanied by slowed motor conduction within the forearm. Existing studies conflict regarding a correlation between the severity of the entrapment neuropathy in carpal tunnel syndrome (CTS) and slowing of median motor nerve conduction velocity (MNCV) in the forearm. Here, it was asked if there is a correlation between markers of CTS severity and median forearm MNCV, and if there is an explanation for the preceding conflicting results.
Median MNCV in the forearm was correlated with neurophysiologic markers of severity of a median neuropathy at the wrist in 91 hands from 64 patients with clinical and electrodiagnostic evidence of CTS.
Median MNCV within the forearm segment was negatively correlated with the median nerve distal motor latency (r=-0.64, P<0.001, n=91) and positively correlated with the CMAP amplitude of the abductor pollicis brevis muscle (r=0.45, P<0.001, n=91). These correlations only occurred in patients with a prolonged median distal motor latency. Previous investigations that failed to find such correlations used variable or non-standardized methods or analyzed smaller numbers of patients.
Slowing of median MNCV in the forearm is related to the severity of the entrapment of median motor fibers at the wrist.
Slowed forearm median MNCV can be a marker of motor nerve injury at the wrist.
腕部正中神经卡压性神经病可能伴有前臂运动传导减慢。关于腕管综合征（CTS）中卡压性神经病的严重程度与前臂正中运动神经传导速度（MNCV）减慢之间的相关性，现有研究存在冲突。在此，研究人员探讨了CTS严重程度标志物与前臂正中MNCV之间是否存在相关性，以及能否解释之前相互矛盾的结果。
对64例有临床和电诊断证据的CTS患者的91只手进行研究，将前臂正中MNCV与腕部正中神经病严重程度的神经生理学标志物进行相关性分析。
前臂段正中MNCV与正中神经远端运动潜伏期呈负相关（r = -0.64，P < 0.001，n = 91），与拇短展肌的复合肌肉动作电位（CMAP）波幅呈正相关（r = 0.45，P < 0.001，n = 91）。这些相关性仅出现在正中远端运动潜伏期延长的患者中。之前未能发现此类相关性的研究采用了可变或非标准化的方法，或者分析的患者数量较少。
前臂正中MNCV减慢与腕部正中运动纤维的卡压严重程度有关。
前臂正中MNCV减慢可能是腕部运动神经损伤的一个标志。
