Department of Neurology, Chiba University Hospital, Chiba, Japan.
J Peripher Nerv Syst. 2009 Sep;14(3):151-8. doi: 10.1111/j.1529-8027.2009.00226.x.
To assess the significance of distal compound muscle action potential (CMAP) duration for diagnosis of demyelinating neuropathies, electrophysiologic data were reviewed from 471 subjects, including 145 normal controls, 60 patients with chronic inflammatory demyelinating polyneuropathy (CIDP), 205 with other neuropathy, and 61 with amyotrophic lateral sclerosis (ALS). The duration of distally evoked CMAP was measured in the median, ulnar, tibial, and peroneal nerves. Optimal cut-off values were calculated with receiver-operating characteristic (ROC) curves. In comparison of normal controls and CIDP patients, ROC analyses showed the sufficient area under the curves (82-93%). When the cut-off values in the detection of demyelination were determined as the point with 98% specificity vs. normal on the ROC curves (median, 6.6 ms; ulnar, 6.7 ms; peroneal, 7.6 ms; tibial, 8.8 ms), the sensitivity was 77% for CIDP, with a specificity of 90% vs. ALS and 95% vs. diabetic neuropathy. The distal CMAP duration is a useful index for the detection of distal demyelination. We suggest the above cut-off values for each nerve as one of the electrodiagnostic criteria for demyelinating neuropathies, preferentially affecting the distal nerve terminals, such as CIDP.
为了评估远端复合肌肉动作电位（CMAP）持续时间对脱髓鞘神经病的诊断意义，回顾了来自 471 名受试者的电生理数据，包括 145 名正常对照者、60 名慢性炎症性脱髓鞘性多发性神经病（CIDP）患者、205 名其他神经病患者和 61 名肌萎缩侧索硬化症（ALS）患者。在正中神经、尺神经、胫神经和腓总神经中测量了远端诱发 CMAP 的持续时间。使用受试者工作特征（ROC）曲线计算最佳截断值。与正常对照组和 CIDP 患者比较，ROC 分析显示曲线下面积足够（82-93%）。当将 ROC 曲线上 98%特异性（相对于正常）的脱髓鞘检测截断值确定为切点时（正中神经，6.6ms；尺神经，6.7ms；腓总神经，7.6ms；胫神经，8.8ms），CIDP 的敏感性为 77%，特异性为 90%，与 ALS 相比，特异性为 95%，与糖尿病性神经病相比。远端 CMAP 持续时间是检测远端脱髓鞘的有用指标。我们建议将每个神经的上述截断值作为脱髓鞘神经病的电诊断标准之一，优先影响远端神经末梢，如 CIDP。
