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RecruitingNCT06874309REBASUpdated Mar 13, 2025

Non-invasive Brain Stimulation to Prepare the Patient for Bariatric Surgery (REBAS)

An interventional study of home-based tDCS stimulation and home-based tDCS stimulation - sham in Obesity, sponsored by Masaryk University. Recruiting at 2 sites in Czechia. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2025-03-13.

Sponsored by Masaryk University · Not applicable, Interventional, and Supportive care

From the registry’s dates

  • Registered 7 months after the study started (first participant enrolled May 2024, registered Dec 2024).
  • Started May 2024; still recruiting 2 years 5 months later.
Phase
Not applicable
Study type
Interventional
Enrollment
65
Allocation
Randomized
Ages
18 Years to 65 Years
Sex
All
01

Study summary

Obesity is a chronic metabolic condition characterized by excessive accumulation of body fat, which triggers physiological mechanisms that increase the risk of a wide range of health problems. The most effective treatment for severe obesity is metabolic-bariatric surgery, which can lead to a 15-20% weight reduction, significantly lowering the risks of illness and death. However, the success of this surgery can be threatened by poor eating habits after the procedure. The main goal of this study is to enhance the long-term effectiveness of bariatric surgery by combining it with non-invasive brain stimulation (tDCS) targeting inhibitory centers before the operation. Additionally, the investigators aim to comprehensively monitor patients before and after surgery, focusing on investigating changes in brain function associated with the achieved weight loss.

Read the detailed description

Obesity, defined as a body mass index (BMI) above 30 kg/m² or through other body composition measurements like waist circumference or body fat percentage, is a major risk factor for cardiovascular, neurological, and oncological diseases. It is one of the leading causes of mortality in both men and women. The prevalence of obesity is increasing globally, particularly among younger populations, surpassing undernutrition and posing significant health and socio-economic challenges.

Excess fat accumulation, a hallmark of obesity, impacts the structure and function of nearly all organ systems. This occurs through both physical mechanisms, such as fat deposition around organs, and functional mechanisms, including chronic low-grade inflammation, insulin resistance, dyslipidemia, and altered hormone production and regulation by adipose tissue.

While various therapies have been developed to address the negative effects of obesity on body structure and function, early interventions like lifestyle changes and pharmacotherapy have shown only mild and often temporary weight reduction. These approaches frequently lead to cyclical weight changes, which have been linked to increased cardiovascular risk.

Bariatric surgery has emerged as the most effective treatment for severe obesity, delivering significant and long-lasting weight reduction compared to lifestyle modifications. While lifestyle interventions typically achieve a weight loss of 5-10%, bariatric surgery can result in reductions of 15-20%. However, a notable challenge is the risk of failure, primarily due to noncompliant eating behaviors after surgery. Approximately 40% of individuals with extreme obesity are at high risk of experiencing suboptimal outcomes following bariatric surgery.

To address this issue, our project aims to improve the sustainability of bariatric surgery outcomes by incorporating neuromodulation before the procedure. Specifically, the investigators propose using transcranial direct current stimulation (tDCS) to enhance prefrontal inhibitory control by targeting the left dorsolateral prefrontal cortex (lDLPFC). This home-based, non-invasive brain stimulation method seeks to improve behavioral regulation, potentially reducing the likelihood of postoperative complications related to eating habits.

Additionally, researchers aim to identify neural, cognitive, and behavioral predictors of successful bariatric surgery outcomes. By examining these factors, investigators plan to optimize treatment strategies, ensuring more effective and sustainable results for individuals undergoing bariatric surgery.

02

Conditions studied

  • Obesity

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Keywords

  • bariatric surgery
  • obesity
  • brain stimulation
  • tDCS
  • cognitive control
  • impulsivity
  • eating behavior
03

In context

Obesity

6,296 studies on the registry are indexed under Obesity; 1,692 are open to participants now.

This study's planned enrollment of 65 is below the median of 78 across 4,878 interventional studies indexed under Obesity.

Browse Obesity studies →

Lead sponsor

Masaryk University is the lead sponsor of 40 studies on the registry; 21 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Subjects with severe or morbid obesity (determined by BMI > 35 or 40 kg/m2, respectively) eligible for BS treatment in compliance with the current guidelines
  • Subjects who meet reduced control over eating behavior (disinhibition) criteria in the Eating Habits Questionnaire

Exclusion criteria

Exclusion Criteria:

  • Subjects unable to provide informed consent and those unable to understand and cooperate with study-related procedures (based on the physician's discretion)
  • Subjects with a personal history of ischemic heart disease, myocardial infarction, stroke, heart failure, and atrial fibrillation
  • Subjects who have already undergone BS treatment in the past
  • Pregnant subjects or subjects that plan on becoming pregnant during the study.
  • Subjects deemed unsuitable for the study based on expert evaluation (e.g., by a physician or neuropsychologist) will be excluded.
  • Subjects with dreadlocks (problematic for the EEG)
05

Study design

Phase
Not applicable
Primary purpose
Supportive care
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
65 participants (estimated)

Study arms

  • Experimental
    active tDCS stimulation

    Participants in this arm will be stimulated for 4 weeks during weekdays leading to 20 sessions of tDCS over lDLPFC.

    Device: home-based tDCS stimulation · Procedure: Bariatric surgery

  • Sham comparator
    sham tDCS stimulation

    In this arm, sham stimulation will be applied for 4 weeks during weekdays leading to 20 sessions of tDCS over lDLPFC.

    Device: home-based tDCS stimulation - sham · Procedure: Bariatric surgery

Interventions

  • Devicehome-based tDCS stimulation

    stimulation parameters: 20 sessions of tDCS over lDLPFC (anode over F3, based on the 10:20 system, and cathode over the right supraorbital area), 2 mA intensity, 20 min duration (30 s fade in/fade out)

  • Devicehome-based tDCS stimulation - sham

    20 sessions of tDCS over lDLPFC (anode over F3, based on the 10:20 system, and cathode over the right supraorbital area), the electric current will flow for only 15 s, with similar fade in/fade out, at the beginning and at the end of 20 min, to mimic the subjective sensations that occur during active tDCS.

  • ProcedureBariatric surgery

    The operation itself is not a study-related procedure and thus the indicated patients would undergo the surgery regardless of their participation in this study. The operating surgeons will perform either Roux-en-Y or gastric sleeve resection.

06

What researchers measure

Primary outcomes

  1. Cognitive impulse control measured via food-modified Go/No-Go task

    The cognitive task is used to assess response inhibition, particularly in the context of food-related stimuli. It is a variation of the standard Go/No-Go task, where participants must respond quickly to "Go" stimuli (low-calorie item) while withholding responses to "No-Go" stimuli (high-calorie item). Researchers analyze reaction times, accuracy, and commission errors (responses to No-Go stimuli) to evaluate impulse control.

    Time frame: Baseline, 1 month and 6 months.

Secondary outcomes

  1. Brain activation related to cognitive control assessed using a multichannel EEG system

    The investigators will evaluate brain activity in response to food-modified Go/No-Go stimuli and during rest, using Time-Frequency Analysis, focusing on theta and beta power.

    Time frame: Baseline, 1 month and 6 months.

  2. Body bioimpedance analysis measured with the InBody 720 device

    Patients, wearing light clothing and standing barefoot with their legs slightly apart, will hold the device's sensors. Within seconds, the device calculates parameters such as total body water, fat mass, muscle mass, and segmental composition.

    Time frame: Baseline, 1 month and 6 months.

  3. Food craving of patients assessed using Food Craving Questionnaire - Trait

    The questionnaire has 21 items with a response scale 1-6, higher score means stronger cravings.

    Time frame: Baseline, 1 month and 6 months.

  4. Eating habits of patients assessed using the Three-Factor Eating Questionnaire

    The Questionnaire has 51 items in total, 36 items ask for true/false judgment, and 15 items are scored on a 4-point Likert-type scale, each item scores either 0 or 1 point, the minimum score for factors Cognitive Restraint, Disinhibition, and Hunger is 0-0-0, the possible maximum score is 21-16-14.

    Time frame: Baseline, 1 month and 6 months.

07

Study locations

2 of 2 sites recruiting
  • Saint Anne's University Hospital
    Brno, 60200, Czechia
    Recruiting
  • Central European Institute of Technology Masaryk University
    Brno, 62500, Czechia
    Recruiting
08

References and documents

Individual participant data

Plan to share: Undecided

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Mar 13, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06874309
Lead sponsor
Masaryk University
Collaborators
St. Anne´s University Hospital Brno
Responsible party
Sponsor
First posted
Mar 13, 2025
Start date
May 1, 2024
Primary completion
Dec 31, 2026 (estimated)
Completion
Dec 31, 2027 (estimated)
Last update
Mar 13, 2025

Study contacts

Petra Holštajn Zemánková, Dr.
Contact
petra.zemankova@mail.muni.cz
+420 776 722 029
Sylvie Kropáčová, Dr.
Contact
sylvie.kropacova@ceitec.muni.cz
Irena Rektorová, Prof.
principal investigator · Cetral European Institute of Technology

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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