Respiratory applications of magnetic stimulation

A. Provoking a bilateral contraction of the diaphragm is a useful way to obtain information about the intrinsic contractile properties of the diaphragm, main agonist of inspiration. This is currently done using transcutaneous electrical stimulation of the phrenic nerves in the neck. The relative painfulness of this procedure limits its use. Magnetic stimulation, applied at the cervical level, stimulates both phrenic nerves, therefore giving non invasiveiy access to the same diaphragm information. B. The control of breathing is classically considered an automatic phenomenon!, depending on brainstem mechanisms. However, cortical projections to the diaphragm exist and allow temporary disruptions of the automatic control. Cortical magnetic stimulation is a simple way to obtain valuable data about the localization of these projections, and their function in the control of breathing.