Current density changes (sLORETA) after right prefrontal 1Hz repetitive transcranial magnetic stimulation in patients with depressive disorder
Abstract
The aim of our study was to examine whether the changes of current density detected by standardized low resolution brain electromagnetic tomography (sLORETA) is different between responders and non-responders to prefrontal rTMS. A total of 25 inpatients with depressive disorder (DSM-IV criteria), who previously did not respond to at least one antidepressant treatment underwent 4 weeks of rTMS treatment (1 Hz, 100 % of motor threshold, 600 pulses/session, 20 session) applied over the right dorsolateral prefrontal cortex.
The effect of rTMS on brain electrical activity (detected by the use of sLORETA) was measured before treatment and 3 days after rTMS treatment separately in responders (reduction of MADRS >= 50 %) and non-responders. The current density in alpha 1 band increased in prefrontal and limbic cortex (Brodman areas 6, 8, 9, 32) bilaterally (p < 0.05, corrected) in a group of nine responders.
No significant changes were detected in non-responders. Our findings implicate that the antidepressants effect of 1Hz rTMS is connected with an increased alfa 1 band current density in the prefrontal cortex.