Paffi Alessandra, Camera Francesca, Apollonio Francesca, d'Inzeo Guglielmo, Liberti Micaela
Department of Information Engineering, Electronics and Telecommunications (DIET), Sapienza University of Rome Rome, Italy.
Front Comput Neurosci. 2015 Feb 19;9:2. doi: 10.3389/fncom.2015.00002. eCollection 2015.
An intraoperative electrode (microelectrode) is used in the deep brain stimulation (DBS) technique to pinpoint the brain target and to choose the best parameters for the electrical stimulus. However, when the intraoperative electrode is replaced with the chronic one (macroelectrode), the observed effects do not always coincide with predictions. To investigate the causes of such discrepancies, a 3D model of the basal ganglia has been considered and realistic models of both intraoperative and chronic electrodes have been developed and numerically solved. Results of simulations of the electric potential (V) and the activating function (AF) along neuronal fibers show that the different geometries and sizes of the two electrodes do not change the distributions and polarities of these functions, but rather the amplitudes. This effect is similar to the one produced by the presence of different tissue layers (edema or glial tissue) in the peri-electrode space. Conversely, an inaccurate positioning of the chronic electrode with respect to the intraoperative one (electric centers not coincident) may induce a completely different electric stimulation in some groups of fibers.
在深部脑刺激（DBS）技术中，术中电极（微电极）用于精确确定脑靶点并为电刺激选择最佳参数。然而，当术中电极被长期电极（宏电极）取代时，观察到的效果并不总是与预测相符。为了研究这种差异的原因，我们考虑了基底神经节的三维模型，并开发了术中电极和长期电极的真实模型并进行了数值求解。沿神经纤维的电势（V）和激活函数（AF）的模拟结果表明，两种电极不同的几何形状和尺寸不会改变这些函数的分布和极性，而是改变其幅度。这种效应类似于电极周围空间中存在不同组织层（水肿或胶质组织）所产生的效应。相反，长期电极相对于术中电极的定位不准确（电中心不重合）可能会在某些纤维组中引起完全不同的电刺激。
