Magnetic stimulation of the peripheral nervous system: influence of the induced transverse electric field on the nervous activation mechanism

Between the components of the induced electric field E, the gradient of the component parallel to the nerve is considered as the activation mechanism of peripheral nerves in magnetic stimulation. Hence, activation occurs only for coil orientation which are capable of inducing such a component. However, there is experimental evidence that coil orientation which are not capable of inducing such a component yield high-amplitude muscle responses. Here, the contribution to the activating function of the component of E perpendicular to the nerve is discussed