Department of Neurology, Graduate School of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, Japan.
Clin Neurophysiol. 2011 May;122(5):1032-41. doi: 10.1016/j.clinph.2010.08.012.
To establish a non-invasive and quantitative analysis method using single-channel surface EMG (SEMG) for diagnosing neurogenic and myopathic changes.
The subjects consisted of 66 healthy controls, 12 patients with neurogenic diseases, and 18 patients with myopathic diseases. The tibialis anterior muscle was examined using a belly to the adjacent bone lead. From each subject, 20-40 signals of 1 s length were collected of various strengths. A new parameter, the "Clustering Index (CI)", was developed to quantify the uneven distribution of the SEMG signal, and was plotted against the SEMG area. The results were expressed as the Z-score of each subject calculated using linear regression from the normative data.
When ±2.5 was used as the cut-off value of the Z-score, the specificity was 95%, whereas the sensitivity was 92% (11/12) and 61% (11/18) for the neurogenic and myopathic patients, respectively. There was no overlap of the Z-score values between the neurogenic and myopathic groups.
The CI method achieved a reasonably high diagnostic yield in detecting neurogenic or myopathic changes.
This is a new simple and quantitative analysis method using SEMG with good reproducibility, and is promising as a non-invasive complement to needle EMG.
建立一种使用单通道表面肌电图（sEMG）进行神经源性和肌源性病变诊断的无创、定量分析方法。
研究对象包括 66 名健康对照者、12 名神经源性疾病患者和 18 名肌源性疾病患者。采用腹部到相邻骨骼导联对胫骨前肌进行检查。从每位受试者中采集 20-40 个 1 秒长度、不同强度的信号。开发了一个新参数“聚类指数（CI）”来量化 sEMG 信号的不均匀分布，并将其与 sEMG 面积进行关联。结果以每个受试者的 Z 分数表示，通过对正常数据进行线性回归计算得出。
当将 Z 分数的±2.5 作为截断值时，特异性为 95%，而对于神经源性和肌源性患者，其敏感性分别为 92%（11/12）和 61%（11/18）。神经源性和肌源性组之间的 Z 分数值没有重叠。
CI 方法在检测神经源性或肌源性变化方面具有较高的诊断收益。
这是一种使用 sEMG 的新的简单、定量分析方法，具有良好的可重复性，有望成为一种有前途的非侵入性补充针肌电图。
