Effect of collateral branching on excitation threshold of dorsal column nerve fibers in spinal cord stimulation

In this paper we present the effect of epidural spinal cord stimulation on myelinated dorsal column nerve fibers. An important feature of these fibers is the presence of collaterals perpendicular to the main fibers. In order to investigate the behavior of these fibers in spinal cord stimulation, we first calulated the potential field in the spinal cord, using a realistic volume conductor model. Second, this field was applied to an electrical network model of the fibers. It is concluded that both excitation threshold and blocking threshold of dorsal column nerve fibers are decreased by 30-503, compared to thresholds of simple straight fibers