Zakutansky Donald W, Kitano Koichi, Wallace Janet P, Koceja David M
Clinical Exercise Physiology Laboratory, Indiana University, Bloomington, Indiana 47405, USA.
J Clin Neurophysiol. 2005 Jun;22(3):210-5.
The authors examined the effect of acute ischemia on peripheral nerve function in healthy subjects. It was hypothesized that acute ischemia would interfere with the ability of sensory and motor nerves to propagate an impulse. Twelve young, apparently healthy adults participated in the study. Soleus H-reflex and motor recruitment curves were determined for subjects during a control condition, after 5 minutes of ischemia by femoral artery occlusion, and after a 5-minute recovery. During ischemia, the stimulus intensity required to evoke an H-reflex or M-wave was reduced by 18.3% and 18.4%, respectively. Hmax/Mmax ratios were significantly reduced with acute ischemia (mean +/- standard error) 66.29% +/- 5.4% and 58.81% +/- 6.7% for control and ischemia, respectively, owing to a decrease in Hmax during acute ischemia with no change in Mmax. After ischemia, the Hmax/Mmax returned to control values, as did the M-threshold. However, although the H-threshold slightly recovered, it failed to return to control threshold after 5 minutes of recovery. The results suggest that acute ischemia decreases motor and H-reflex thresholds in healthy individuals with a longer lasting effect for the H-reflex. In addition, a decrease in Hmax/Mmax ratio was observed, suggesting that acute ischemia has differential effects on sensory nerve propagation and synapse transmission.
作者研究了急性缺血对健康受试者外周神经功能的影响。研究假设急性缺血会干扰感觉神经和运动神经传导冲动的能力。12名年轻、看似健康的成年人参与了该研究。在对照状态下、股动脉闭塞5分钟缺血后以及5分钟恢复后，测定了受试者的比目鱼肌H反射和运动募集曲线。在缺血期间，诱发H反射或M波所需的刺激强度分别降低了18.3%和18.4%。急性缺血时Hmax/Mmax比值显著降低（平均值±标准误差），对照和缺血时分别为66.29%±5.4%和58.81%±6.7%，这是由于急性缺血期间Hmax降低而Mmax无变化。缺血后，Hmax/Mmax恢复到对照值，M阈值也恢复到对照值。然而，尽管H阈值略有恢复，但在恢复5分钟后未能恢复到对照阈值。结果表明，急性缺血会降低健康个体的运动和H反射阈值，对H反射的影响持续时间更长。此外，观察到Hmax/Mmax比值降低，表明急性缺血对感觉神经传导和突触传递有不同影响。
