Poster No:
99
Submission Type:
Abstract Submission
Authors:
Gizem Vural1,2, Antonia Šušnjar3, Lucia Bulubas4, Eva Mezger5, Andre Brunoni6, Birgit Ertl-Wagner7, Sophia Stoecklein5, Stephan Goerigk8,9, Aldo Soldini5, Joanna Moussiopoulou10, Frank Padberg4, Daniel Keeser4
Institutions:
1LMU Klinikum, Munich, Other, 2General and Experimental Psychology Ludwig-Maximilians-University, Munich, Germany, 3Purdue University, West Lafayette, IN, 4Department of Psychiatry and Psychotherapy, University Hospital LMU, Munich, Germany, 5LMU Klinikum, Munich, Bavaria, 6Department of Psychiatry and Laboratory of Neurosciences Institute of Psychiatry, São Paulo, Estado de Sao Paulo, 7Department of Diagnostic Imaging, The Hospital for Sick Children, Ontario, Ontario, 8Ludwig-Maximilians-University of Munich , Munich, Bavaria, 9 LMU · Department of Psychology, N/A, 10LMU Klinikum, München, Germany
First Author:
Gizem Vural
LMU Klinikum|General and Experimental Psychology Ludwig-Maximilians-University
Munich, Other|Munich, Germany
Co-Author(s):
Lucia Bulubas
Department of Psychiatry and Psychotherapy, University Hospital LMU
Munich, Germany
Andre Brunoni
Department of Psychiatry and Laboratory of Neurosciences Institute of Psychiatry
São Paulo, Estado de Sao Paulo
Birgit Ertl-Wagner
Department of Diagnostic Imaging, The Hospital for Sick Children
Ontario, Ontario
Stephan Goerigk
Ludwig-Maximilians-University of Munich | LMU · Department of Psychology
Munich, Bavaria
Frank Padberg
Department of Psychiatry and Psychotherapy, University Hospital LMU
Munich, Germany
Daniel Keeser
Department of Psychiatry and Psychotherapy, University Hospital LMU
Munich, Germany
Introduction:
Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation technique that is gaining attention for its potential to modulate cortical brain activity, with applications in cognition and potential treatment options in various psychiatric conditions including major depressive disorder (MDD) and schizophrenia (SCZ). This study aimed to investigate how bifrontal tDCS might influence brain metabolite concentrations within the medial prefrontal cortex (mPFC). To achieve this, we employed a concurrent tDCS-magnetic resonance spectroscopy (MRS) setup, allowing us to observe potential changes in brain chemistry associated with the application of tDCS in real-time.
Methods:
A total of 30 subjects with MDD (20 men, mean age 30.4±11), and 23 subjects with SCZ (17 men, mean age 35.78±11) and 36 healthy control subjects (26 men, mean age 31±10), matched for age and gender with the MDD and SCZ samples participated. A 3 Tesla Siemens Skyra MRI scanner in conjunction with a neuroConn DC-Stimulator MR device was used for the study. In vivo MRS was obtained utilizing a MEGA-PRESS sequence to monitor neurometabolic shifts before, during, and after 20 min of 2 mA tDCS administration with 5 x 7 cm electrodes. The anode was positioned over F3 (left DLPFC) and the cathode over F4 (right DLPFC). Stimulation sessions were performed in a randomized and counterbalanced order in a cross-over design.
Results:
Before the application of tDCS, a baseline comparison between the groups was performed to evaluate inherent differences in metabolite concentrations under both active and sham conditions. Accordingly, the MDD group exhibited higher Glu and Glx concentrations compared to the healthy group.
To evaluate the tDCS effect, baseline corrected metabolite concentrations were quantified as separate analyses for each group comparing active and sham conditions. The notable finding emerged in the SCZ group, where active tDCS initially had a significant impact on NAA concentrations compared to sham in the beginning of the stimulation. However, this effect did not persist throughout the stimulation period.
Comprehensive group comparisons further revealed pronounced differences in NAA concentrations, with SCZ group having significantly lower values compared to the healthy group. Furthermore, in both active and sham conditions, the healthy group exhibited significantly higher NAA, Glu, and Glx levels compared to the MDD group during the study period.
Conclusions:
The findings shed light on the neurochemical underlying prefrontal tDCS for our study subjects at the two specific measurement times, highlighting possible cross-sectional utility for two major psychiatric diseases.
MDD patients exhibited inherently higher concentrations of Glu and Glx compared to healthy controls, suggesting a potential neurochemical distinction associated with major depressive disorder.
Contrastingly, when examining the metabolite levels over time, our results indicated a consistent decrease in all three metabolite concentrations in the MDD group compared to healthy controls. However, the absence of a significant three-way interaction (group by stimulation by time) suggests that these observed reductions are not dependent on the type of stimulation-active or sham.
Interestingly, while tDCS influenced metabolite levels in the SCZ group, the effects were transient, indicating a temporary neurochemical response to tDCS in schizophrenia.
Nevertheless, the absence of certain findings does not rule out possible effects on NAA, Glu, and Glx levels in lateral prefrontal regions or under varying tDCS conditions, such as different montages, intensities, and durations. Future research employing multi-voxel MRS might address these gaps and allow for a more comprehensive localization of the effects of tDCS on neurotransmitter levels, including network effects over predefined regions of interest.
Brain Stimulation:
Non-invasive Electrical/tDCS/tACS/tRNS 2
TDCS 1
Disorders of the Nervous System:
Psychiatric (eg. Depression, Anxiety, Schizophrenia)
Novel Imaging Acquisition Methods:
MR Spectroscopy
Physiology, Metabolism and Neurotransmission :
Physiology, Metabolism and Neurotransmission Other
Keywords:
DISORDERS
Glutamate
Magnetic Resonance Spectroscopy (MRS)
Neurotransmitter
Psychiatric Disorders
1|2Indicates the priority used for review
Provide references using author date format
Mezger, E. (2021). Effects ofbifrontal transcranial direct current stimulation on brain glutamate levels and resting state connectivity: multimodal MRI data for the cathodal stimulation site. European archives of psychiatry and clinical neuroscience, 271(1), 111-122.