Does Neuromodulation Modulate Obesity?

Over the past decades, numerous neuromodulation therapies have been proposed to alter several of the physiological processes underpinning obesity, ranging from the brain control of food intake, satiety, and compulsive eating, to gastrointestinal responses. 

These neuromodulation approaches include deep brain stimulation [DBS], transcranial magnetic stimulation [TMS], transcranial direct current stimulation [tDCS], percutaneous neurostimulation [PENS], vagus nerve stimulation [VNS], and gastric electrical stimulation [GES]. 

So far, none of these treatments have made it into routine practice, and according to a review by Flavia Gouveia and colleagues, published in Obesity Reviews, there are probably good reasons for this, the principle one being lack of effectiveness. 

Thus, their review of 60 trials that had weight loss as an outcome,  including 7 DBS, 5 TMS, 7 tDCS, 17 PENS and VNS, and 24 GES in over 3,000 participants, yielded a seemingly consistent pattern. Initial promising results in open label studies and case reports, followed by double-blinded randomized clinical trials that generally failed to reach their primary endpoints, with no technique inducing a striking long-term reduction in body weight.

As the authors note, both the case reports and randomised trials were fraught with important sources of bias or lacked details of important confounders. 

While the authors remain cautiously enthusiastic about the future of neuromodulation, it is fair to say that at this time these approaches must be considered experimental and should probably not be used outside of well-controlled clinical trials. 

Berlin, D