Shefner Jeremy M, Rutkove Seward B, Caress James B, Benatar Michael, David William S, Cartwright Michael S, Macklin Eric A, Bohorquez Jose L
a Department of Neurology , Barrow Neurological Institute , Phoenix , AZ , USA.
b Department of Neurology , Beth Israel Deaconess Medical Center and Harvard Medical School , Boston , MA , USA.
Amyotroph Lateral Scler Frontotemporal Degener. 2018 Nov;19(7-8):555-561. doi: 10.1080/21678421.2018.1510008. Epub 2018 Sep 28.
In this longitudinal multicenter cohort study, we evaluated the potential of a dedicated electrical impedance myography (EIM) device to assess ALS progression and the system's basic reproducibility and diagnostic accuracy.
Forty-six ALS patients underwent up to five sequential measurements of multiple muscles over a period of 8 months at 2-month intervals using the mView EIM device (Myolex, Inc., San Francisco, CA). Standard measures of disease status were also obtained. A group of 30 healthy volunteers and 30 ALS-mimics were evaluated once to determine if the technique could assist with initial diagnosis. Several electrode arrays and EIM outcomes were assessed.
EIM tracked ALS progression; power analyses suggested a 5.2-fold reduction in sample size requirements compared to ALSFRS-R by utilizing 50 kHz phase value from the muscle with the greatest EIM decline in each subject. This progression rate correlated to total ALSFRS-R progression, with R = 0.371, p = 0.021. Reproducibility was high, with both intra- and inter-rater intraclass correlation coefficients for individual muscles mostly greater than 0.90. The mean 50 kHz phase distinguished between ALS patients and healthy controls (area-under-curve 0.78, 95% confidence intervals (CIs) 0.68, 0.89), but not between mimics and ALS patients (area-under-curve 0.60, 95% CIs 0.47, 0.73).
While limited in its specificity to identify ALS versus disease mimics, these results support the hypothesis that single-muscle EIM can serve as a convenient, repeatable, and powerful outcome measure in ALS clinical trials.
在这项纵向多中心队列研究中，我们评估了专用电阻抗肌电图（EIM）设备评估肌萎缩侧索硬化症（ALS）进展的潜力以及该系统的基本可重复性和诊断准确性。
46例ALS患者使用mView EIM设备（Myolex公司，加利福尼亚州旧金山）在8个月内每隔2个月对多块肌肉进行多达5次连续测量。还获取了疾病状态的标准测量值。对30名健康志愿者和30名ALS模拟患者进行了一次评估，以确定该技术是否有助于初步诊断。评估了几种电极阵列和EIM结果。
EIM跟踪了ALS的进展；功效分析表明，通过利用每个受试者中EIM下降最大的肌肉的50kHz相位值，与ALSFRS-R相比，样本量要求降低了5.2倍。这种进展率与总的ALSFRS-R进展相关，R = 0.371，p = 0.021。可重复性很高，个体肌肉的评分者内和评分者间组内相关系数大多大于0.90。平均50kHz相位能够区分ALS患者和健康对照（曲线下面积0.78，95%置信区间（CI）0.68，0.89），但不能区分模拟患者和ALS患者（曲线下面积0.60，95%CI 0.47，0.73）。
虽然在识别ALS与疾病模拟方面特异性有限，但这些结果支持以下假设，即单肌肉EIM可作为ALS临床试验中一种方便、可重复且有力的结果测量方法。
