Eldred E, Perlmutter S I
Department of Anatomy, UCLA School of Medicine 90024.
Am J Phys Med. 1987 Oct;66(5):287-97.
Previously the application of stimuli of 600 Hz at adjustable strength applied to a muscle's nerve has been proposed as a means of reducing the muscle's contraction in spastic conditions, or when combined with a second tetanic stimulation, of limiting contraction to smaller, physiologically more relevant motor units in the paralyzed state. The side-effects on muscle spindles of such stimuli as seen in the cat's gastrocnemius are reported. During stimulation axonal impulses followed faithfully for periods running into minutes. After stimulation, a pause in ongoing firing with a duration dependent on stimulus-train length and a two-phased recovery occurred. Responses to dynamic stretch of the muscle were affected as well. The contractions of intrafusal fibers activated in several ways was seen to strongly offset the depression. In a clinical application, nevertheless, short-lived depression of all proprioceptive modalities following stimulation should be expected, with corresponding disturbance on sensory perception and reflex effects.
此前有人提出，将强度可调的600赫兹刺激施加于肌肉神经，可作为一种减少痉挛状态下肌肉收缩的方法，或者在与第二次强直刺激相结合时，在瘫痪状态下将收缩限制在更小的、生理上更相关的运动单位。本文报道了此类刺激对猫腓肠肌肌梭的副作用。在刺激过程中，轴突冲动会忠实地持续跟随数分钟。刺激后，持续放电出现暂停，其持续时间取决于刺激串的长度，并出现两阶段恢复。对肌肉动态拉伸的反应也受到了影响。以多种方式激活的肌梭内纤维的收缩被发现能强烈抵消这种抑制。然而，在临床应用中，预计刺激后所有本体感觉模式都会出现短暂抑制，并对感觉知觉和反射效应产生相应干扰。
