| Abstract [eng] |
The work evaluated the effect of transcranial magnetic stimulation (TMS) on the bioelectrical brain activity (EEG) of patients with treatment resistant depression (TRD). The work also determined the relationship between these changes and the serum concentration of a potential biomarker of depression, brain neurotrophic factor (BDNF). Patients' EEG readings were recorded before and after the course of TMS treatment. Healthy control group’s readings were also analysed and their quantitative parameters were calculated. In the study, patients underwent intermittent theta burst stimulation protocol (iTBS). This protocol consisted of two-second-long 50 Hz 3-pulse discharges at 5 Hz. The results of BDNF serum levels in TRD patients and the control (healthy) group, as well as the results of clinical tests of HAM-D and MADRS in TRD patients were also analysed during the study. The master’s thesis found that the activities of the theta, alpha and beta frequency range of TRD patients before iTBS therapy were higher compared to the healthy control group. The results obtained after iTBS therapy show that theta, alpha and beta activities remained significantly higher, and that delta activity significantly increased compared to the healthy control group. Analysis of TRD patients before and after TMS therapy showed a significant decrease in alpha activity in the occipital region, with no significant change observed at other frequencies. TMS therapy resulted in a significant increase in BDNF levels. When comparing the effect of TMS therapy on BDNF serum levels with a healthy control group’s levels, there was no significant difference between these groups. Correlation between BDNF serum levels of TRD patients with their EEG before TMS resulted in a significant negative correlation in the delta and theta frequency ranges in central and parietal lobes. The correlation of the healthy control group’s BDNF levels and EEG readings showed a significant positive correlation between delta – temporal, theta – right frontal and right temporal, beta – right frontal, right temporal, and parietal lobes. Analysis of changes in the clinical trials showed that iTBS significantly reduced depressive symptoms. |
