Estimating functional excitation-inhibition ratios during electroconvulsive therapy

Abstract Background: Electroconvulsive therapy (ECT) has been used successfully for over 80 years and is the most effective treatment patients suffering from major depressive disorder (MDD). Despite different hypotheses have proposed, exact working mechanisms of ECT are still unknown. To improve response rates, it necessary to enhance our understanding biological that may affect MDD how treat this condition. One suggests disturbances in balance between synaptic excitation inhibition (i.e., E/I ratio) play an important role pathogenesis MDD. Objective: estimate functional ratios with treated study whether change related clinical effectiveness. Methods: Prior a maximum 13 consecutive ECT-sessions, five-minute resting-state electroencephalogram (EEG; 19 leads + ground) was recorded their eyes closed. Functional were calculated evolution these determined ECT-course using exponential curve fit. Before after ECT-course, Hamilton Rating Scale Depression (HRSD)-scores as outcome measure. Results: A total 234 usable EEG recordings 25 ECT-patients could be included. In theta frequency band (4-7 Hz) we found increased (P<0.05) electrodes Fp2, F8, C4, T4 T3 towards more recovered ratio values. Increases not No differences established other bands. Conclusions: During estimated (right) frontotemporal central regions, although increase appeared associated Research Category Technology Methods Translational Research: 2. Therapy Keywords: electroencephalogram, excitation, inhibition,