Neuromodulation with electromagnetic stimulation for seizure suppression: From electrode to magnetic coil

Highlights • Electrode-generated currents exhibit several limitations when used to suppress seizure in clinical practice. • Magnetic stimulation provides enhanced biocompatibility, efficiency, and consistency over implanted electrode. • Clinical cases that utilize magnetic fields for epilepsy treatment are effective and relatively safe. • Current understanding of the cellular mechanisms underlying magnetic control of epileptic circuitry is insufficient. • In vivo and in vitro animal models are developed for neurological studies pertaining to the magnetic suppression of seizure.
Non-invasive brain tissue stimulation with a magnetic coil provides several irreplaceable advantages over that with an implanted electrode, in altering neural activities under pathological situations. We reviewed clinical cases that utilized time-varying magnetic fields for the treatment of epilepsy, and the safety issues related to this practice. Animal models have been developed to foster understanding of the cellular/molecular mechanisms underlying magnetic control of epileptic activity. These mechanisms include (but are not limited to) (1) direct membrane polarization by the magnetic field, (2) depolarization blockade by the deactivation of ion channels, (3) alteration in synaptic transmission, and (4) interruption of ephaptic interaction and cellular synchronization. Clinical translation of this technology could be improved through the advancement of magnetic design, optimization of stimulation protocols, and evaluation of the long-term safety. Cellular and molecular studies focusing on the mechanisms of magnetic stimulation are of great value in facilitating this translation.