Tashjian E A, Ellenberg M R, Gross N, Chodoroff G, Honet J C
Arch Phys Med Rehabil. 1987 Sep;68(9):549-52.
The measurement of sensory nerve action potential (SNAP) latency and amplitude is often necessary to accurately diagnose disorders of peripheral nerves. The sensory evoked response can be obtained using either the antidromic (AD) or orthodromic (OD) technique. In a previous study we demonstrated that in healthy subjects the AD SNAP distal latency of median and ulnar nerves at 14 cm distance is approximately 0.2 msec slower than the OD SNAP distal latency at 32C. The AD SNAP amplitude was also two times greater than the OD SNAP amplitude. In this study we observed that these differences between the AD and OD SNAP latency and amplitude varied significantly as temperature changed. The AD median nerve SNAP distal latency was delayed by .06 msec/degree with cooling. The OD median nerve SNAP distal latency was delayed by .03 msec/degree with cooling. These values represent less of a slowing per degree centigrade cooling than has been previously noted in the literature. The median nerve SNAP amplitude was found to increase with upper extremity cooling with the AD and OD technique by 3.5 microV and 0.5 microV per degree, respectively. For accurate interpretation of SNAP latency and amplitude, the electromyographer must be familiar with the technique used and the differing effect of the temperature with each technique.
测量感觉神经动作电位（SNAP）的潜伏期和波幅对于准确诊断周围神经疾病常常是必要的。感觉诱发电位可通过逆向（AD）或顺向（OD）技术获得。在先前的一项研究中，我们证明，在健康受试者中，在32℃时，正中神经和尺神经在14厘米距离处的AD SNAP远端潜伏期比OD SNAP远端潜伏期约慢0.2毫秒。AD SNAP波幅也比OD SNAP波幅大两倍。在本研究中，我们观察到，随着温度变化，AD和OD SNAP潜伏期及波幅之间的这些差异有显著变化。冷却时，AD正中神经SNAP远端潜伏期每度延迟0.06毫秒。冷却时，OD正中神经SNAP远端潜伏期每度延迟0.03毫秒。这些值表示每摄氏度冷却时的减慢程度比先前文献中所指出的要小。发现正中神经SNAP波幅在使用AD和OD技术使上肢冷却时分别以每度3.5微伏和0.5微伏的幅度增加。为了准确解释SNAP潜伏期和波幅，肌电图检查者必须熟悉所使用的技术以及每种技术中温度的不同影响。
