Nandedkar S D, Barkhaus P E, Sanders D B, Stålberg E V
Division of Neurology, Duke University Medical Center, Durham, NC 27710.
Electroencephalogr Clin Neurophysiol. 1988 Jun;69(6):561-7. doi: 10.1016/0013-4694(88)90168-x.
Computer simulations indicate that measurements of the area of motor unit action potentials (MUAPs) recorded with a concentric needle electrode could be useful in differentiating between neuropathy and myopathy. However, MUAP area varies markedly when the position of the recording electrode is changed only slightly within the motor unit territory, mainly because of the changes in the MUAP amplitude produced by only slight electrode movements. The ratio of MUAP area to amplitude is much less affected by changes in electrode position and measures the 'thickness' of the MUAP wave form. We found that the MUAP area:amplitude ratio was reduced in myopathy even when the MUAP amplitude was normal or increased. In patients with neuropathy, the MUAP amplitude and area both tend to be increased while their ratio is normal or increased. The diagnostic yield obtained from MUAP area, amplitude and their ratio in combination was similar to that obtained using measurements of MUAP duration. Unlike the MUAP duration, the MUAP area, amplitude and area:amplitude ratio are robust features of the MUAP in that they are less sensitive to the signal-to-noise ratio and inter-operator differences in signal selection.
计算机模拟表明，用同心针电极记录的运动单位动作电位（MUAPs）面积测量值可能有助于区分神经病变和肌病。然而，当记录电极在运动单位区域内仅轻微改变位置时，MUAP面积会有显著变化，这主要是由于电极的轻微移动仅产生MUAP波幅的变化。MUAP面积与波幅的比值受电极位置变化的影响小得多，并且可测量MUAP波形的“厚度”。我们发现，即使MUAP波幅正常或增加，在肌病中MUAP面积与波幅的比值仍会降低。在神经病变患者中，MUAP波幅和面积往往都增加，而它们的比值正常或增加。联合使用MUAP面积、波幅及其比值所获得的诊断率与使用MUAP时限测量值所获得的诊断率相似。与MUAP时限不同，MUAP面积、波幅以及面积与波幅的比值是MUAP的稳定特征，因为它们对信噪比和信号选择时操作者间的差异不太敏感。
