Duration of the Distal Compound Muscle Action Potential for Diagnosis of Chronic Inflammatory Demyelinating Polyneuropathy: Effects of Low-Cut Filters

作者：Isose Sagiri^*; Misawa Sonoko; Sonoo Masahiro; Shimuzu Toshio; Oishi Chizuko; Shibuya Kazumoto; Nasu Saiko; Sekiguchi Yukari; Mitsuma Satsuki; Beppu Minako; Omori Shigeki; Komori Tetsuo; Kokubun Norito; Inaba Akira; Hirashima Fumiko; Kuwabara Satoshi

来源：Journal of Clinical Neurophysiology, 2014, 31(5): 441-443.

DOI：10.1097/WNP.0000000000000045

• Chronic inflammatory demyelinating polyneuropathy
• Compound muscle action potential
• CMAP duration

Purpose:In current electrodiagnostic criteria for chronic inflammatory demyelinating polyneuropathy, the cutoff values of distal compound muscle action potential (DCMAP) duration are defined using electromyogram low-cut filter setting of 20 Hz. We aimed to assess effects of low-cut filter on DCMAP duration (10 vs. 20 Hz).Methods:We prospectively measured DCMAP duration in 130 normal controls and 42 patients, fulfilling diagnostic criteria for typical chronic inflammatory demyelinating polyneuropathy by European Federation of Neurological Societies/Peripheral Nerve Society.Results:Distal compound muscle action potential duration was significantly shortened with 20-Hz than 10-Hz filtering. When the cutoff values were defined as the upper limit of normal (ULN, mean + 2.5SD), the sensitivity/specificity was 67%/95% in 10-Hz recordings, and 69%/95% in 20-Hz recordings. This diagnostic accuracy was similar to that defined by receiver operating characteristic analyses.Conclusions:Distal compound muscle action potential duration significantly affected by the low-cut electromyogram filter setting, but with at least 10 and 20 Hz, the diagnostic accuracy is similar.

• 出版日期2014-10