Repetitive transcranial magnetic stimulation:: the introduction of a new therapeutic tool in psychiatry

Transcranial magnetic stimulation (TMS) is a technique used for investigation of the tics, when repeatedly applied, has a therapeutic potential, notably in psychiatry, The physiological and neuroendocrine effects induced by repeated TMS treatment in an animal model are similar to those caused by antidepressants in man. In particular. TMS appears to modify the release of neuromediators (serotonin, dopamine) involved in depressive states. Because of these properties, repeated TMS has been proposed as a potential treatment for depression. Several randomized studies have now evaluated its effects in this regard and for the most part show statistically significant results. although the findings are sometimes modest at the clinical level. However, the therapeutic effects depend on various parameters which are generally not taken into account, such as cortical excitability and regional cerebral metabolism, Apart from depression, the trials focus on a limited number of disorders. In schizophrenia. the use of TMS has permitted abnormalities in cortical excitability to be demonstated and an improvement of the symptomatology, e,g, by suppressing the perception of auditory hallucinations. Parkinson's disease. nervous twitch and Gilles de la Tourette syndome. obsessive-compulsive disorders and mania have also been the focus of promising albeit preliminary trials. Wider randomized studies should now assess the different parameters involved in the therapeutic effects, so that the treatment procedure can be optimized and the physiopathology of various neuropsychiatric disorders better understood. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.