Adaptive current-flow models of ECT: Explaining individual static impedance, dynamic impedance, and brain current density

Abstract

The physical properties of the Electroconvulsive Therapy (ECT) stimulus markedly effect both efficacy and cognitive side effects. Combining records of clinical ECT, device measurements, and MRI-derived FEM computational head models, we consider the sources and relationship between static impedance, dynamic impedance, and current delivered to the brain. To this end, we develop the first adaptive models of transcranial Electrical Stimulation, where local tissue conductivity is modulated by electric field. The models predict subject-specific static impedance and dynamic impedance, provide insight into their relationship, and predicts how ECT shapes tissue conductance and so how current reaches the brain.