Department of Neurological Sciences, Neuromuscular Investigation Laboratory, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, São Paulo, Brazil.
Muscle Nerve. 2011 Dec;44(6):912-8. doi: 10.1002/mus.22203.
Our objective was to study jitter parameters using a concentric needle electrode (CNE) in the extensor digitorum (ED) and frontalis (FR) muscles.
Twenty myasthenia gravis (MG) patients, mean age 44.5 years, were studied. Percutaneous (FR) and intramuscular needle (ED) stimulation approaches were used. Jitter was expressed as the mean consecutive difference (MCD). The filter settings were from 1000 HZ to 10 kHZ.
Abnormal MCD was found in 85% for both ED and FR and in 90% when combining the two muscles. An abnormal percentage of outliers was found in 90% for ED and 85% for FR. The mean MCD did not show a difference for ED and FR, but the percentage of outliers and blocking were higher in FR. Abnormality was found in 93.7% (generalized) and in 75% (ocular) of MG cases. For ED outliers abnormality was greater than the MCD.
CNE jitter is reliable for investigation of MG, although borderline findings should be judged with caution.
我们的目的是使用同心针电极（CNE）研究伸肌（ED）和额肌（FR）中的抖动参数。
研究了 20 例重症肌无力（MG）患者，平均年龄 44.5 岁。采用经皮（FR）和肌内针（ED）刺激方法。抖动表示为连续差异的平均值（MCD）。滤波器设置为 1000 HZ 至 10 kHZ。
ED 和 FR 两种肌肉的异常 MCD 均发现 85%，两种肌肉结合后发现 90%。ED 的异常离群率为 90%，FR 为 85%。ED 和 FR 的平均 MCD 没有差异，但 FR 的离群率和阻滞率较高。93.7%（全身性）和 75%（眼肌型）MG 病例存在异常。对于 ED 离群值异常大于 MCD。
CNE 抖动对于 MG 的检查是可靠的，尽管边界发现应谨慎判断。
