Manola Ljubomir, Holsheimer Jan, Veltink Peter, Buitenweg Jan R
Biomedical Signals and Systems Group, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands.
Clin Neurophysiol. 2007 Feb;118(2):464-74. doi: 10.1016/j.clinph.2006.09.012. Epub 2006 Dec 5.
To explore the effects of electrical stimulation performed by an anode, a cathode or a bipole positioned over the motor cortex for chronic pain management.
A realistic 3D volume conductor model of the human precentral gyrus (motor cortex) was used to calculate the stimulus-induced electrical field. The subsequent response of neural elements in the precentral gyrus and in the anterior wall and lip of the central sulcus was simulated using compartmental neuron models including the axon, soma and dendritic trunk.
While neural elements perpendicular to the electrode surface are preferentially excited by anodal stimulation, cathodal stimulation excites those with a direction component parallel to its surface. When stimulating bipolarly, the excitation of neural elements parallel to the bipole axis is additionally facilitated. The polarity of the contact over the precentral gyrus determines the predominant response. Inclusion of the soma-dendritic model generally reduces the excitation threshold as compared to simple axon model.
Electrode polarity and electrode position over the precentral gyrus and central sulcus have a large and distinct influence on the response of cortical neural elements to stimuli.
Modeling studies like this can help to identify the effects of electrical stimulation on cortical neural tissue, elucidate mechanisms of action and ultimately to optimize the therapy.
探讨将阳极、阴极或双极电极置于运动皮层上进行电刺激对慢性疼痛管理的效果。
使用逼真的人类中央前回（运动皮层）三维容积导体模型来计算刺激诱发的电场。随后，使用包含轴突、胞体和树突干的房室神经元模型模拟中央前回以及中央沟前壁和唇缘中神经元件的反应。
垂直于电极表面的神经元件优先被阳极刺激所兴奋，而阴极刺激则兴奋那些具有与其表面平行方向分量的神经元件。双极刺激时，平行于双极轴的神经元件的兴奋会进一步得到促进。中央前回上接触点的极性决定了主要反应。与简单的轴突模型相比，纳入胞体 - 树突模型通常会降低兴奋阈值。
电极极性以及中央前回和中央沟上的电极位置对皮层神经元件对刺激的反应有巨大且明显的影响。
这样的建模研究有助于确定电刺激对皮层神经组织的影响，阐明作用机制，并最终优化治疗方法。
