双重刺激脊髓反射及其对颈神经根损害的评定

双重刺激中的第二刺激能消除阈上刺激所兴奋的F波。这样就可利用双重刺激来探讨在消除F波情况下的H反射成分。本试验研究拇短展肌和小指展肌，单个刺激时，观察F波出现率为9．84％，双重刺激时F波消失。利用平均叠加技术，在消除F波时，H反射在健康人均可清晰引出。用此方法对30例颈神经根损害患者测试，发现有不同程度H反射潜伏时延长、波幅降低或引不出来。用双重刺激消除F波，为在不严格控制刺激强度的条件下清晰地引出H反射提供了简单、快捷和可靠的方法。

Double Stimulation Spinal Reflex and Its Assessment to Cervical Root Disorder

Single F wave evoked by stimulation with above threshold intensity are canceled by a second shock. Thus double stimulation of any intensity makes it possible to detect H reflex component in the spinal response by elimination of the F wave. F wave and H reflex were studied in the abductor pollicis brevis. The probability of F wave evoked by single stimulation was 9. 84%. But F wave was canceled by double stimulation. When F wave was canceled by double stimulation, H reflex was recorded clearly with average and sum.Using this technique, it was found that H renex in 30 patients with cervical root disorder was abnormal, including prolonged latency, decreased amplitude, even absence of response in the serious cases. For any intensity of stimulation eliciting an H response, the double stimulation is an easily quick and safe procedure to evoke H reflex by elimination of the F wave.