Noninvasive enhancement of the brain circuit of inhibitory control in obese patients undergoing laparoscopic adjustable gastric banding

Souheil W Adra, MD, Greta A Magerowski, BA, George L Blackburn, MD, PhD, Miguel Alonso-Alonso, MD, MPhil, Benjamin E Schneider, MD

Beth Israel Deaconess Medical Center, Harvard Medical School

Introduction and objectives:

Laparoscopic Adjustable Gastric Banding (LAGB) is a minimally invasive and reversible procedure in bariatric surgery that has a good safety record but variable success rates across patients. Recent data suggest that complementing LAGB with interventions targeting the brain could have a potential benefit in weight loss outcomes. In this project, we aim to examine whether enhancing the right inferior gyrus, a core region in the brain involved in inhibitory control, can improve eating control capacity and subsequently enhance post-operative weight loss.

Method:

Study design: This is a proof-of-concept, double-blinded, randomized, sham-controlled, parallel study consisting of a baseline visit and a 10-day intervention starting the second week after surgery, and follow-up visits at 1, 3, 6 and 12 months. Intervention: We use noninvasive neuromodulation with transcranial direct current stimulation (tDCS) targeting the right inferior frontal gyrus, together with computerized training of inhibitory control. Patients are randomized to receive either an active intervention or a control/sham intervention. Outcome measures: The primary outcome is postsurgical weight loss at one year (clinical effect). Secondary outcomes include performance in an inhibitory control task (target circuit engagement), and a self-reported measure of eating control (behavioral effect). Patient selection: A total of 40 obese patients undergoing LAGB will be recruited from the Minimally Invasive Surgical Unit at Beth Israel Deaconess Medical Center. Inclusion criteria are 20-55 years, body mass index (BMI) of 35-60 kg/m2. Exclusion criteria are pregnancy, any active psychiatric or neurological condition at the time of joining the study, or any contraindication to receive tDCS. The study is registered at https://www.clinicaltrials.gov/ct2/show/NCT01632280.

Preliminary results:

To date, we have recruited a total of 9 patients (6 females and 3 males). The study is ongoing and all the available data is blinded. The intervention is being well tolerated by all the participants. There has not been any serious or unexpected adverse events. Approximately 75% of patients reported transient mild sensations at the site of the electrode while receiving tDCS (tingling, itching, burning and pain), which is in line with previous studies and our own experience. The baseline characteristics of patients are as follows (mean +/- SD): age 41.3 +/- 5.0, BMI 40.7 +/- 5.3, three factor eating questionnaire score dietary restraint 10.7 +/- 4.5, disinhibition 9.2 +/- 4.1, hunger 8.0 +/- 5.2. At 1 month post-intervention (n=3) % weight loss from baseline is: 12.7 +/- 1.8, BMI 32.9 +/- 1.2, % excess weight loss (%EWL) 15.8% +/- 4.2 (24.8% in one patient at 3 months follow-up). All available data (%EWL) is shown in Figure 1.

Conclusion:

The study is ongoing. The intervention is feasible and has been well tolerated by the patients to date. Available data, albeit limited and very preliminary, suggest substantial weight loss overall. The contribution of the study intervention remains uncertain at present, because the study is still blinded.

Session: Poster Presentation

Program Number: ETP059