Monocentric Pilot Study, for a Randomized, Crossover, Blinded Trial: Comparison of the Therapeutic Efficacy of Low Frequency Repeated Transcranial Magnetic Stimulation on Cortical Area 9 Compared to Brodmann Area 46 in the Treatment of Depressive Disorders.

Repetitive transcranial magnetic stimulation (rTMS) is a new therapeutic tool used in psychiatry. Non-invasive, well tolerated and requiring no premedication, it is performed on an outpatient basis. The principle of this technique is to stimulate the cerebral cortex from an electromagnetic coil placed on the scalp. Unlike electroconvulsive therapy, rTMS induces an electrical current on a well-defined region of the cerebral cortex.

In psychiatry, this technique is mainly considered in the treatment of depressive disorders resistant to antidepressant medication. The brain target, obtained from brain imaging data in depressed patients, is the dorsolateral prefrontal cortex (DLPFC). The Food and Drug Administration (FDA) has recognized the interest of rTMS for treating depressive disorders (October 7, 2008).

However, some stimulation parameters still need to be optimized before rTMS can be considered a therapeutic method in its own right and used routinely. Indeed, its effectiveness over time has not yet been evaluated, and rTMS has shown a lack of reproducibility between subjects [Foucher, 2007]. Finally, the therapeutic results of rTMS are very modest whatever the study [Daskalakis, 2008]. Additional studies are therefore needed to optimize stimulation parameters.