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Simultaneous EEG Monitoring During Transcranial Direct Current Stimulation
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Comparing Different Montages of Transcranial Direct Current Stimulation in Treating Treatment-Resistant Obsessive
Che-Sheng Chu1,2,3,4, Yen-Yue Lin5,6,7, Cathy Chia-Yu Huang7
1Department of Psychiatry, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan.
Medicina (Kaunas, Lithuania)
|February 26, 2025
Summary
Dual-site cathodal transcranial direct current stimulation (tDCS) over the orbitofrontal cortex (OFC) and pre-supplementary motor area (pre-SMA) showed promising results for treatment-resistant obsessive compulsive disorder (OCD). This dual-site tDCS approach led to sustained symptom improvement and altered brain network connectivity.
Area of Science:
- Neuroscience
- Psychiatry
- Medical Engineering
Background:
- Transcranial direct current stimulation (tDCS) is an emerging non-invasive brain stimulation technique.
- Obsessive compulsive disorder (OCD) is a debilitating condition, particularly in treatment-resistant cases.
- Current tDCS protocols for OCD involve various electrode placements with varying efficacy.
Purpose of the Study:
- To compare the effectiveness of a novel dual-site cathodal tDCS montage (OFC-pre-SMA) against established montages (cerebellum-OFC, pre-SMA).
- To evaluate the impact of different tDCS montages on symptom severity in treatment-resistant OCD patients.
- To investigate the effects of tDCS on brain network connectivity, specifically the default mode network (DMN).
Main Methods:
- Eighteen patients with treatment-resistant OCD were randomly assigned to three tDCS groups (n=6 each).
- Intervention involved twice-daily 2 mA/20 min sessions for 10 weekdays using cerebellum-OFC, pre-SMA, or OFC-pre-SMA cathodal tDCS.
- Primary outcome measure was the change in Yale-Brown Obsessive Compulsive Scale (Y-BOCS); resting EEG was used to analyze DMN connectivity.
Main Results:
- All tDCS groups showed a reduction in Y-BOCS scores, with the OFC-pre-SMA group demonstrating the largest mean decrease (-20.75%).
- Symptom improvement in the OFC-pre-SMA group was sustained at one week and one month post-stimulation.
- OFC-pre-SMA tDCS increased frontal network connectivity, while cerebellum-OFC tDCS decreased DMN connectivity.
Conclusions:
- Dual-site cathodal tDCS over the OFC and pre-SMA presents a potential therapeutic montage for treatment-resistant OCD.
- The OFC-pre-SMA montage may offer sustained benefits and influence specific brain network dynamics.
- Further research with randomized sham-controlled trials is warranted to confirm these findings.
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