Cornblath D R, Kuncl R W, Mellits E D, Quaskey S A, Clawson L, Pestronk A, Drachman D B
Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Muscle Nerve. 1992 Oct;15(10):1111-5. doi: 10.1002/mus.880151009.
Nerve conduction studies (NCS) are an integral part of the evaluation of amyotrophic lateral sclerosis (ALS) patients and are useful in distinguishing ALS from disorders that mimic it. The question often arises whether in the presence of severe atrophy and reduction of the compound muscle action potential amplitude, abnormal conduction velocity (CV), distal latency (DL), or F-wave latency (F) exceeds what can be expected from ALS alone. To determine the limits of abnormality in classic ALS, we prospectively evaluated NCS data from 61 patients who met a strict clinical definition of ALS. We related CV, DL, and F to distal evoked amplitude (AMP) in peroneal (n = 63 observations), median (n = 50), and ulnar (n = 52) nerves. In nerves with reduced AMP, CV rarely fell to less than 80% of the lower limit of normal, and DL and F rarely exceeded 1.25 times the upper limit of normal. Utilizing the entire data set and regression analyses, 95% confidence limits for expected values for CV, F, and DL as a function of AMP were calculated. These limits thus derived suggest criteria for NCS abnormalities in ALS and may be useful in differentiating ALS from other illnesses.
神经传导研究（NCS）是评估肌萎缩侧索硬化症（ALS）患者不可或缺的一部分，有助于将ALS与类似疾病区分开来。经常会出现这样的问题：在存在严重萎缩以及复合肌肉动作电位幅度降低的情况下，异常的传导速度（CV）、远端潜伏期（DL）或F波潜伏期（F）是否超过了仅由ALS所预期的范围。为了确定经典ALS中异常的限度，我们前瞻性地评估了61例符合严格ALS临床定义患者的NCS数据。我们将腓总神经（n = 63次观察）、正中神经（n = 50次）和尺神经（n = 52次）的CV、DL和F与远端诱发电位幅度（AMP）进行关联。在AMP降低的神经中，CV很少降至正常下限的80%以下，DL和F很少超过正常上限的1.25倍。利用整个数据集和回归分析，计算出了作为AMP函数的CV、F和DL预期值的95%置信区间。由此得出的这些限度为ALS中NCS异常提供了标准，可能有助于将ALS与其他疾病区分开来。
