Lupu Vitalie D, Mora Carlos A, Dambrosia Jim, Meer Jacob, Dalakas Marinos, Floeter Mary Kay
EMG Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.
Muscle Nerve. 2007 Feb;35(2):196-202. doi: 10.1002/mus.20678.
Neuropathy with antibodies against myelin-associated glycoproteins (MAG/SGPG-N) and hereditary sensorimotor neuropathy type 1 (HMSN1) are characterized by chronic demyelination with little conduction block. Electrodiagnostic studies suggest that in HMSN1 conduction slowing occurs uniformly along the nerve, whereas in MAG/SGPG-N it is predominantly distal. Some but not all previous reports have shown that the terminal latency index (TLI) was useful to distinguish MAG/SGPG-N from chronic idiopathic demyelinating polyneuropathy. We compared median TLI from 21 patients with MAG/SGPG-N with those obtained from 26 patients with HMSN1, 20 with HMSN2, and 12 healthy volunteers. All patients with TLI <0.26 had MAG/SGPG-N, and all patients with TLI > or =0.32 had HMSN1. In the remaining patients with intermediate TLI values, ulnar distal motor latency (DML) aided in differentiation between MAG/SGPG-N and HMSN1 with an overall sensitivity of 100% and specificity of 98%. In conclusion, median TLI in combination with ulnar DML can further guide the demyelinating neuropathy evaluation toward hereditary or autoimmune causes.
抗髓鞘相关糖蛋白（MAG/SGPG-N）性神经病和遗传性感觉运动神经病1型（HMSN1）的特征是慢性脱髓鞘，传导阻滞较少。电诊断研究表明，在HMSN1中，神经传导减慢沿神经均匀发生，而在MAG/SGPG-N中，主要是远端传导减慢。一些（但不是所有）先前的报告表明，终末潜伏期指数（TLI）有助于将MAG/SGPG-N与慢性特发性脱髓鞘性多发性神经病区分开来。我们比较了21例MAG/SGPG-N患者的正中神经TLI与26例HMSN1患者、20例HMSN2患者和12名健康志愿者的正中神经TLI。所有TLI<0.26的患者患有MAG/SGPG-N，所有TLI≥0.32的患者患有HMSN1。在其余TLI值处于中间范围的患者中，尺神经远端运动潜伏期（DML）有助于区分MAG/SGPG-N和HMSN1，总体敏感性为100%，特异性为98%。总之，正中神经TLI与尺神经DML相结合可以进一步指导对脱髓鞘性神经病的评估，以区分其遗传或自身免疫病因。
