Struijk J J, Holsheimer J, Boom H B
Department of Electrical Engineering, University of Twente, Enschede, The Netherlands.
IEEE Trans Biomed Eng. 1993 Jul;40(7):632-9. doi: 10.1109/10.237693.
In epidural spinal cord stimulation it is likely that not only dorsal column fibers are activated, but that dorsal root fibers will be involved as well. In this investigation a volume conductor model of the spinal cord was used and dorsal root fibers were modeled by an electrical network including fiber excitation. The effects of varying some geometrical fiber characteristics, as well as the influence of the dorsal cerebrospinal fluid layer and the electrode configuration on the threshold stimulus for their excitation, were assessed. The threshold values were compared with those of dorsal column fibers. The results of this modeling study predict that, besides the well known influence of fiber diameter, the curvature of the dorsal root fibers and the angle between these fibers and the spinal cord axis were of major influence on their threshold values. Because of these effects, threshold stimuli of dorsal root fibers were relatively low as compared to dorsal column fibers. Excitation of the dorsal root fibers occurred near the entry point of the fibers.
在硬膜外脊髓刺激中，很可能不仅背柱纤维会被激活，背根纤维也会参与其中。在本研究中，使用了脊髓的容积导体模型，背根纤维通过包含纤维兴奋的电网络进行建模。评估了改变一些几何纤维特征的影响，以及背侧脑脊液层和电极配置对其兴奋阈值刺激的影响。将阈值与背柱纤维的阈值进行了比较。该建模研究的结果预测，除了众所周知的纤维直径影响外，背根纤维的曲率以及这些纤维与脊髓轴之间的角度对其阈值有主要影响。由于这些影响，与背柱纤维相比，背根纤维的阈值刺激相对较低。背根纤维的兴奋发生在纤维的入口点附近。
