| Abstract [eng] |
Recently rTMS emerged as a new clinical tool for the treatment of major depressive disorder. rTMS is noninvasive and easily tolerated method that is able to alter bioelectrical brain activity. This phenomenon is achieved by using alternating magnetic fields to induce electric currents in cortical tissue. Nowadays it is widelly accepted that lateralized alterations in brain activity might play a role in depressive symptoms. It has been found that major depressive disorder patients exhibit greater right frontal activity in contrast to left frontal hypoactivation (it should be noted, that cortical activity is inversely related with alpha power). Therefore rTMS is a potential method that can help to re-eastablish normal brain activity. In this study we examined effects of different rTMS parameters (protocols and stimulation coils) on bioelectrical brain activity modulation in patients with the treatment resistant major depressive disorder. It was shown that 10 Hz stimulation with the figure-eight coil over the left prefrontal area increases alpha power in the right hemisphere. In addition, it was demonstrated that 1 Hz stimulation over the left prefrontal cortex changes frontal alpha asymmetry. It should be underlined, that there appears to be no significant difference in clinical efficacy between the two protocols. It was also demonstrated that changes in frontal alpha asymmetry tend to correlate with the outcome of the treatment. Furthermore, it was shown that stimulation with the round coil, compared with the figure-eight coil, produces more complex, diffused effects. Summarizing, our results suggest that rTMS indeed alters bioelectrical brain activity. Different affects were recorded of rTMS protocols and stimulation coils on EEG spectrum modulation. |
