Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
Clin Neurophysiol. 2011 Dec;122(12):2505-11. doi: 10.1016/j.clinph.2011.04.021. Epub 2011 May 25.
Human studies have shown that electrical impedance myography (EIM), a technique based on the surface application of high-frequency, low-intensity electrical current to localized areas of muscle, is sensitive to muscle denervation. In this study, we examined the role of EIM as a potential biomarker for assessing ALS disease progression in the SOD1 transgenic rat by comparing it to motor unit number estimation (MUNE).
Multi-frequency EIM and MUNE were performed twice weekly in 16 rats from approximately 10 weeks of age onward. Four different EIM measures were evaluated, including the previously studied 50 kHz phase and three condensed multi-frequency parameters.
The rate of deterioration in the multi-frequency phase data from 100-500 kHz had the strongest correlation to survival (ρ=0.79, p<0.001), surpassing that of MUNE (ρ=0.57, p=0.020). These two measures were also strongly correlated (ρ=-0.94, p<0.001) to one another.
These findings support that EIM is an effective tool for assessing disease progression in the ALS rat.
Given its ease of application and ability to assess virtually any superficial muscle, EIM deserves further study as a biomarker in human ALS clinical therapeutic trials.
人体研究表明，基于向肌肉局部区域施加高频、低强度电流的表面应用的电阻抗肌描记术（EIM）对肌肉失神经支配敏感。在这项研究中，我们通过将其与运动单位数量估计（MUNE）进行比较，检查 EIM 作为评估 SOD1 转基因大鼠 ALS 疾病进展的潜在生物标志物的作用。
从大约 10 周龄开始，每周两次对 16 只大鼠进行多频 EIM 和 MUNE 检查。评估了四种不同的 EIM 测量方法，包括之前研究的 50 kHz 相位和三种浓缩多频参数。
100-500 kHz 多频相位数据的恶化率与生存率的相关性最强（ρ=0.79，p<0.001），超过了 MUNE（ρ=0.57，p=0.020）。这两个指标彼此之间也具有很强的相关性（ρ=-0.94，p<0.001）。
这些发现支持 EIM 是评估 ALS 大鼠疾病进展的有效工具。
鉴于其易于应用和评估几乎任何表浅肌肉的能力，EIM 值得进一步研究作为人类 ALS 临床治疗试验中的生物标志物。
