A mechanism of seizure induction by electricity and its clinical implications

Abstract

A model of ECT seizure induction by rapid kindling is described. The electrical stimulus as a series of pulses progressively disrupts neuronal cell membranes, with corresponding progressive increases in intracellular concentrations of sodium, calcium, and voltage. Eventually, the intracellular voltage rises to trigger neuronal firing in waves from seizure foci. The quantity of seizure foci produced is expressed by the stimulus charge multiplied by the current cubed. Differences in implications are described between this model and the traditional model that extrapolates from an isolated single neuron undergoing immediate electrical depolarization by a single pulse. Total brain exposure to seizure neurotransmitter release in ECT is analogous to body exposure to medication in drug therapy and may be expressed by a physiological measurement such as electroencephalographic postictal suppression or peak seizure heart rate.