Effect of Transcranial Direct Current Stimulation (tDCS) on Appetite Control Related Brain Regions

Study Overview
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Brief Summary
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The purpose of this study is to investigate the effect of Transcranial Direct Current Stimulation (tDCS) on appetite control related brain regions.

Detailed Description
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Transcranial direct current stimulation (tDCS) is emerging tool for brain modulation in a variety of clinical conditions. In addition, recent neuroimaging studies suggest that modifying the activity of brain circuits involved in eating behavior could provide therapeutic benefits in obesity. The investigators aim to assess whether modulation of the dorsolateral prefrontal cortex (DLFPC) using tDCS, modifies behavioral response and brain activity while watching visually presented food cues in obese subjects. Subjects will receive tDCS two times, one is active stimulation and the other is sham stimulation. Both stimulations will be separated at least one week and the order of sham and active tDCS will be counterbalanced across subjects. Subjects will perform functional MRI experiments with visual food cues. Questionnaire with behavior measures, body compositions, blood tests will be performed.

Official Title
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Effect of Transcranial Direct Current Stimulation (tDCS) on Appetite Control Related Brain Regions

Conditions
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Obesity

Intervention / Treatment
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* Device: tDCS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI > 28 kg/m2 Exclusion Criteria: history of brain trauma, epilepsy, or other neurological problems

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sham tDCS<br>Subjects will receive tDCS two times, one is active stimulation and the other is sham stimulation. Both stimulations will be separated at least one week and the order of sham and active tDCS will be counterbalanced across subjects. | Device: tDCS<br>* For active tDCS, a 2 mA current will be delivered for 20 minutes with 20 second up and down ramp times. The anodal electrode will be placed on the right DLPFC (F4; 10-20 EEG system), and the cathode electrode will be placed on the left DLPFC (F4;10-20 EEG system), which is known to be related to cognitive function. The electrodes used for tDCS are saline-soaked sponges (25 cm2).<br>|
| Experimental: Real tDCS<br>Subjects will receive tDCS two times, one is active stimulation and the other is sham stimulation. Both stimulations will be separated at least one week and the order of sham and active tDCS will be counterbalanced across subjects. | Device: tDCS<br>* For active tDCS, a 2 mA current will be delivered for 20 minutes with 20 second up and down ramp times. The anodal electrode will be placed on the right DLPFC (F4; 10-20 EEG system), and the cathode electrode will be placed on the left DLPFC (F4;10-20 EEG system), which is known to be related to cognitive function. The electrodes used for tDCS are saline-soaked sponges (25 cm2).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Regional brain activity measured by blood-oxygen-level dependent (BOLD) signal of functional MRI | 3T MR scanner with Echo Planar Imaging(EPI) capability(Magnetom, Siemens Medical System) | Immediately after intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Behavior outcomes on the visual analog scale | Hunger related visual analogue scale (VAS) - 8 items (Flint et al., 2000) Mood related visual analogue scale (VAS) - 16 items (Fregni et al., 2008) | Immediately after intervention |