Brooke J D, Staines W R, Cheng J, Misiaszek J E
Human Neurophysiology Laboratory, School of Human Biology, University of Guelph, Ontario.
Electromyogr Clin Neurophysiol. 1997 Nov-Dec;37(8):451-61.
The magnitudes of cerebral somatosensory evoked potentials (SEPs), following stimulation of cutaneous or muscle afferents in the upper limb, are reduced during active and passive movements of the fingers. The generalizability of such a movement effect was tested for lower limb events. We measured SEP magnitudes following activation of cutaneous (sural) and mixed (tibial) nerves during the flexion phase of active and passive rhythmic movements of the human lower limb. In eight volunteers, 150 SEPs per condition were recorded from Cz' referenced to Fpz'. Compared to stationary controls, both active and passive movements significantly depressed the early SEP components (P1-N1) [mean values, to 12.8%, 9.9% respectively for tibial nerve and to 29.6%, 25.6% for sural nerve stimulation, p < 0.05]. The attenuation was still observed when only one leg was moved and with stimulation at an earlier point in the flexion phase of movement. Visual fixation did not significantly affect P1-N1 amplitudes, compared to eyes closed. As previously shown, soleus H reflexes with stable M waves were significantly depressed during the movements (p < 0.05). The general construct may be that centripetal flow initiated from somatosensory receptors during limb movement leads to modulation of both spinal and cortical responses following large diameter cutaneous or muscle afferent activation.
在上肢皮肤或肌肉传入神经受到刺激后，大脑体感诱发电位（SEP）的幅度在手指主动和被动运动期间会降低。针对下肢情况测试了这种运动效应的普遍性。我们在人类下肢主动和被动节律性运动的屈曲阶段，测量了激活皮肤（腓肠神经）和混合（胫神经）神经后的SEP幅度。在8名志愿者中，每种情况下从Cz'记录150个SEP，参考电极置于Fpz'。与静止对照组相比，主动和被动运动均显著压低了早期SEP成分（P1 - N1）[平均值，胫神经刺激分别降至12.8%、9.9%，腓肠神经刺激降至29.6%、25.6%，p < 0.05]。当仅移动一条腿且在运动屈曲阶段的较早点进行刺激时，仍观察到衰减。与闭眼相比，视觉注视对P1 - N1振幅没有显著影响。如先前所示，在运动期间比目鱼肌H反射与稳定的M波相比显著降低（p < 0.05）。一般的机制可能是，肢体运动期间从体感感受器起始的向心信息流，在大直径皮肤或肌肉传入神经激活后，会导致脊髓和皮层反应的调制。
