COMPUTER MODELING OF SPINAL-CORD STIMULATION AND ITS CONTRIBUTION TO THERAPEUTIC EFFICACY

An overview of computer models developed since the late seventies, whi ch enable the simulation of the primary effects of spinal cord stimula tion (SCS) on nerve fibres, is presented. These models consist of a 3- dimensional volume conductor model, representing anatomical structures and their electrical conductivities, and cable models representing th e electrical behaviour of nerve fibres. The characteristics of these m odels and their relation to anatomy and physiology, as well as the cal culation of stimulation-induced electrical fields and their effect on nerve fibre models, are reviewed. It is shown that most characteristic s of SCS as predicted by computer modelling correspond well with empir ical data. Accordingly, a theoretical framework describing the relatio ns between relevant parameters in SCS is presented. Finally, it is sho wn how theory and computer modeling are applied to improve the efficac y of SCS by the optimization of its technique, primarily by the design of new epidural electrodes.