General principles for clinical use of repetitive transcranial magnetic stimulation (rTMS).

Repetitive transcranial magnetic stimulation (rTMS), a non-invasive technique allowing stimulating neurons in the cerebral cortex, is able to modify durably local as well as distant neuronal activity. Results obtained by stimulation of the primary motor cortex and measurements of induced muscle responses suggest that effects on cortical excitability depend on stimulation frequency and intensity, as well as of pulse-train duration. Such data, as well as results of animal studies have brought a physiological basis for the use of rTMS for treatment of various neurological and psychiatric disorders, and particularly depression. Nevertheless, as long as large randomized studies have not been conducted, rTMS should not replace other existing and validated therapies.