Temperatures and Voltages From the Electroconvulsive Therapy Stimulus

Abstract

Introduction Brain voltage and temperature during electroconvulsive therapy (ECT) are not widely understood but are commonly mischaracterized as resembling a blast. Method To better understand brain voltage and temperature during ECT, basic mathematical structural models were constructed and calculations were made. In addition, thermographic images were recorded before and after ECT stimuli were applied to a pork shoulder. Results A basic structural voltage model indicates that the voltage drop across single brain neurons is about 6 mV, with a gradient of 0.6 V/cm. This is an order of magnitude smaller than the action potential. Basic structural temperature models indicate that 100 joules raises skin temperature underneath ECT electrodes no more than 1°C, and within the brain by much less. The average temperature increase at each electrode was 0.70 to 0.94°C. Conclusions Voltage gradients and temperatures in the brain during the ECT stimulus are well within the range of ordinary physiological functioning. These results are consistent with previous reports that only a small fraction of the electrical stimulus enters the brain.