Dewald J P, Given J D, Rymer W Z
Sensory-Motor Performance Program, Rehabilitation Institute of Chicago, IL, USA.
IEEE Trans Rehabil Eng. 1996 Dec;4(4):231-42. doi: 10.1109/86.547923.
We studied the effects of electrical stimulation of the skin on upper extremity spasticity in nine hemiparetic stroke subjects. The effects were quantified by comparing reflex torque responses elicited during ramp and hold angular perturbations of the elbow recorded before and after low-intensity skin stimulation. Electrical stimulation was applied to skin over the biceps muscle for a period of ten minutes at a 20 Hz frequency, pulse duration 0.1 ms, with an intensity level below motor threshold but above sensory threshold. In seven of the nine subjects, stimulation of skin over spastic muscle reduced peak torque responses in both flexors and extensors for at least 30 min. In these seven subjects there were significant increases in mean threshold angle for the onset of reflex torque so that a greater angular rotation was required to initiate the stretch reflex response. This shift occurred without change in reflex impedance. The origins of these long-term changes in reflex torque are unclear, but may reflect synaptic plasticity of spinal circuitry outside the stretch reflex loop.
我们研究了对9名偏瘫性中风患者进行皮肤电刺激对上肢痉挛的影响。通过比较在低强度皮肤刺激前后记录的肘部斜坡和保持角度扰动期间引发的反射扭矩反应来量化这些影响。以20Hz的频率、0.1ms的脉冲持续时间，对肱二头肌上方的皮肤进行电刺激，持续10分钟，强度水平低于运动阈值但高于感觉阈值。在9名受试者中的7名中，对痉挛肌肉上方的皮肤进行刺激可使屈肌和伸肌的峰值扭矩反应至少降低30分钟。在这7名受试者中，反射扭矩开始的平均阈值角度显著增加，因此需要更大的角度旋转来引发牵张反射反应。这种变化在反射阻抗不变的情况下发生。这些反射扭矩长期变化的起源尚不清楚，但可能反映了牵张反射回路外脊髓神经回路的突触可塑性。
