Parry G J, Aminoff M J
Neurology. 1987 Feb;37(2):313-6. doi: 10.1212/wnl.37.2.313.
We recorded somatosensory evoked potentials (SEPs) over the scalp in eight patients with chronic acquired demyelinating peripheral neuropathy. They were obtained from 15 nerves in which sensory nerve action potentials (SNAPs) were absent or not more than 1 microV, but from which motor responses could be elicited. Motor and sensory (SEP-derived) conduction velocity was determined from the difference in response latency with wrist and elbow stimulation. In 11 nerves, afferent conduction velocity was slowed. In 10, there was relatively equal slowing in sensory and motor axons, whereas in 1 there was disproportionate slowing in afferent fibers. In four nerves, afferent conduction velocity was within the normal range despite slowing of motor conduction. We conclude that SEPs may be useful in evaluating peripheral sensory conduction in the absence of SNAPs, but can provide misleadingly normal data, presumably because of central amplification of an attenuated response arising from a few axons that conduct normally.
我们记录了8例慢性获得性脱髓鞘性周围神经病患者头皮上的体感诱发电位（SEP）。这些电位来自15条神经，其中感觉神经动作电位（SNAP）缺失或不超过1微伏，但能引出运动反应。运动和感觉（源自SEP）传导速度由手腕和肘部刺激时反应潜伏期的差异确定。在11条神经中，传入传导速度减慢。在10条神经中，感觉和运动轴突的减慢相对相等，而在1条神经中，传入纤维的减慢不成比例。在4条神经中，尽管运动传导减慢，但传入传导速度仍在正常范围内。我们得出结论，在没有SNAP的情况下，SEP可能有助于评估周围感觉传导，但可能会提供误导性的正常数据，推测这是由于少数正常传导轴突产生的衰减反应在中枢放大所致。
