Target determination for transcranial magnetic stimulation in patients with a pharmacotherapy-resistant depressive episode based on the individual parameters of resting-state functional magnetic resonance imaging (a pilot blind controlled trial)

Abstract

High-frequency repetitive transcranial magnetic stimulation (rTMS) is approved by the Food and Drug Administration (FDA) for the treatment of pharmacotherapy-resistant depressive disorders (DD). Individual target determination for stimulation can be one of the approaches that can increase the efficiency of the technique. Objective: to compare of the effectiveness and tolerability of standard and personalized rTMS protocols.Patients and methods. The investigation enrolled 30 patients with pharmacotherapy-resistant DD who were pseudo-randomized into two groups matched for age, gender, and episode severity. In the study group, the target was located at a point within the left dorsolateral prefrontal cortex (DLPFC) with maximum negative functional connectivity of the subgenual cingulate cortex. In the control group, the stimulation point was 5 cm anterior to the primary motor cortex (hand area). All the patients underwent 20 sessions of high-frequency rTMS DLPFC. For clinical evaluation, the investigators used the Beck Depression Inventory (BDI) and the 36-item Short Form Health Survey (SF-36) questionnaire before and after 10 and 20 rTMS sessions, respectively. Tolerability was assessed using the standardized questionnaires during and within 24 hours after each session. Results and discussion. The study group showed a significant reduction in BDI scores and an increase in the SF-36 (“Mental Health” section) scores after both 10 and 20 rTMS sessions; the control group had those only after 20 sessions. The two groups exhibited no significant differences in the reduction of BDI scores before and after 10 and 20 sessions, respectively. The investigation can be considered to be pilot in searching for algorithms to enhance the efficiency of rTMS DLPFC in pharmacotherapy-resistant depression using the algorithm for personification of target selection. It demonstrated the more rapid onset of a clinical effect in the study group patients. No serious adverse events were reported. The patients had dizziness, headache, and contraction of the facial muscles during the session; headache and mood changes within 24 hours after it. Conclusion. In both groups, rTMS was satisfactorily tolerated and effective; however, personalized target selection accelerated the onset of a clinical effect.

Keywords

• repetitive transcranial magnetic stimulation
• depression
• resting-state functional magnetic resonance imaging
• functional connectivity