Prefrontal repetitive transcranial magnetic stimulation as add on treatment in depression.

Abstract

A growing number of studies report antidepressant effects of repetitive transcranial magnetic stimulation (rTMS) in patients with major depression. The hypothesis that high frequency (20 Hz) rTMS (HF-rTMS) may speed up and strengthen the therapeutic response to sertraline in MD was tested. Twenty eight patients who had not yet received medication for the present depressive episode (n=12) or had failed a single trial of an antidepressant medication (n=16) were started on sertraline and randomised to receive either real of sham HF-rTMS. HF-rTMS was applied to the left dorsolateral prefrontal area in daily sessions (30 trains of 2 s, 20-40 s intertrain interval, at 90% motor threshold) on 10 consecutive working days. The results suggest that in this patient population, HF-rTMS does not add efficacy over the use of standard antidepressant medication.

(J Neurol Neurosurg Psychiatry 2001;71:546-548)

Keywords: major depression; transcranial magnetic stimulation; sertraline; prefrontal area

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive method of inducing a fairly localised current in the cortex of the human brain. A time varying magnetic field is generated by a brief current pulse passed through a stimulation coil held over the subject's scalp. The magnetic field penetrates the scalp and skull unattenuated. The rapid change of the magnetic field induces a current strong enough to depolarise neurons and thus modify the activity in the targeted cortical area and trans-synaptically in functionally connected brain structures. [1 2] If appropriate guidelines are followed rTMS is safe and has minimal side effects. [3]

Most of a growing number of studies on rTMS in depression report antidepressant effects applying high frequency stimulation (HF-rTMS; [greater than]1 Hz) over the left prefrontal cortex, whereas others have employed low frequency rTMS (LF-rTMS; [less than]1 Hz) over the right prefrontal cortex (for reviews see George et al, [1] Reid et al, [4] and Menkes et al [5]). Nevertheless, few controlled studies …