Following fMRI mapping (functional Magnetic Resonance Imaging), it consists in applying a magnetic impulse to the brain through the skull in a painless way by placing a coil on the surface of the head. We create a variable magnetic field by passing a well-controlled alternative electric current through a coil in an insulating girdle. When we place it near the head, the field triggers an electric activity in the cerebral cortex. The low frequency currents (< 1 Hz) reduce the activity and the high frequency currents increase it. Thanks to the passage of an electric current in a "coil" placed on the scalp, we create a perpendicularly oriented directed magnetic field; This magnetic field leads in turn in the neighboring tissues a parallel electric current - but of opposite direction- to the current of stimulation. In other words the SMT is an electric stimulation, but obtained without electrodes and having no major unwanted side effects.
These magnetic fields lead to an electric field which thus modifies the activity of neurones situated in the magnetic field of the TMS. The current use of the TMS is the repetitive stimulation (rTMS ) which consists in giving a series of impulses during an interval of time so as to modify appreciably the activity of the targeted region.
We can control the intensity of the stimulation, the cerebral region to be stimulated, the frequency of the trains of delivered impulses. A frequency lower than 1 Hz is supposed to have an inhibitive effect on the targeted neurons. If superior to 3 Hz, it would be excitatory.
At present it is well established that chronic tinnitus is associated with an increase in the activity of the temporo-parietal cerebral cortex. The modulation of this aberrant activity by magnetic rTMS can contribute to the treatment of tinnitus which resist to classic treatments. Since 2003, European researchers proved the therapeutic potential of the TMS in the treatment of the chronic tinnitus. The researches in this field continue actively to ' to increase the efficiency of the therapeutic protocols. The rTMS used at low frequency on the left primary auditory cortex allows to treat this disorderof hyperexcitability and to reduce or to relieve the buzzing in ears. Two treatments a day during five days are needed at least to feel the beneficial effects of the treatment. The treatment of the tinnitus is extremely targeted. The patients have to wear a swim cap on which the sites to be stimulated are marked.
EXTRACTS OF RECOGNIZED ARTICLES BY THE SCIENTIFIC COMMUNITY AND PUBLISHED IN MEDICAL REVIEWS ABOUT rTMS AND TINNITUS
« This study demonstrates that it is possible to use regularly the rTMS to control chronic tinnitus. A regular treatment could prevent the frequency of the tinnitus from extending in the neighboring areas of the cerebral cortex. »(Mennemeier et al., 2008)
« an evaluation made after three months demonstrated the beneficial effects of the treatment by SMTr combined(organized) by the prefrontal and temporal zone. These results confirm recent data suggesting the involvement of the zones of hearing and non-hearing brain in the physiopathology of tinnitus. »(Kleinjung et al., 2008)
« a low frequency prolonged stimulation (1 Hz) turned out effective for 62.5 % of the patients. The effect was experienced 48 hours after the treatment and went on during approximately five days. »(Londero et. al., 2006)
« the rate of tinnitus sharply improved after five days of active rTMS, which did not occur during a placebo stimulation. »(Kleinjung et.al., 2006)
« after an active rTMS, we were able to note a moderate improvement of the perception of tinnitus. For certain patients, the effects of the treatment were experienced during almost six months. »(Langguth et. al., 2006)