title: Relationship between neural activation and electric field distribution during deep brain stimulation.
abstract: Models and simulations are commonly used to study deep brain stimulation (DBS). Simulated stimulation fields are often defined and visualized by electric field isolevels or volumes of tissue activated (VTA). The aim of the present study was to evaluate the relationship between stimulation field strength as defined by the electric potential V, the electric field E, and the divergence of the electric field ∇(2) V, and neural activation. Axon cable models were developed and coupled to finite-element DBS models in three-dimensional (3-D). Field thresholds ( VT , ET, and ∇(2) VT ) were derived at the location of activation for various stimulation amplitudes (1 to 5 V), pulse widths (30 to 120 μs), and axon diameters (2.0 to 7.5 μm). Results showed that thresholds for VT and ∇(2) VT were highly dependent on the stimulation amplitude while ET were approximately independent of the amplitude for large axons. The activation field strength thresholds presented in this study may be used in future studies to approximate the VTA during model-based investigations of DBS without the need of computational axon models.
authors.affiliation: Department of Biomedical Engineering, Linköping University, Linköping, Sweden.
authors.forename: Mattias
authors.initials: M
authors.lastname: Astrom
authors.affiliation: Department of Biomedical Engineering, Linköping University, Linköping, Sweden.
authors.forename: Elin
authors.initials: E
authors.lastname: Diczfalusy
authors.affiliation: Sapiens Steering Brain Stimulation B.V., Eindhoven, The Netherlands.
authors.forename: Hubert
authors.initials: H
authors.lastname: Martens
authors.affiliation: Department of Biomedical Engineering, Linköping University, Linköping, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Wardell
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D001369:Axons / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D003198:Computer Simulation; D046690:Deep Brain Stimulation / Q000379:methods*; D005071:Evoked Potentials / Q000502:physiology*; D006801:Humans; D008959:Models, Neurological; D009431:Neural Conduction / Q000502:physiology