Figure 1
From: Simulating epileptic seizures using the bidomain model
Computational geometries (a) An idealised two-dimensional model of a slice of the head with, from the top, scalp (orange), skull (yellow/pale green), cerebrospinal fluid (blue), grey matter (dark grey and red), and white matter (two shades of light grey). The central grey matter (red) is modelled by an unstable neuronal model, Model B, while the rest of the grey matter (dark grey) is modelled by a stable neuronal model, model A. The conductivity is isotropic, except in the white matter. The anisotropic conductivity tensor in the white matter is oriented vertically in the left part and horizontally in the right part. The simulated electric potential is measured at locations marked by black dots (b) The three-dimensional patient specific head model. The colours are the same as in (a), however, the ventricles are marked dark blue, and the right hippocampus is marked in red. Note that the ventricles are modelled the same way as the cerebrospinal fluid. As in (a), the grey matter is modelled by Model A, while the right hippocampus is modelled by Model B. (c) A slice of the head model in (b). The simulated electric potential is measured at locations marked by the black dots. (d) The mean diffusivity is highest in the ventricles and the cerebrospinal fluid, both showing up in red. The mean diffusivity is \(1/3~Tr{(M)}\), where \(M\) is the conductivity tensor. The conductivities are measured in \(\text {mS}/\text {cm}\).
