Editorial: Deep brain stimulation and obesity

Abstract

Whiting and coauthors present a pilot study of deep brain stimulation (DBS) in the lateral hypothalamic area (LHA) to treat obesity in 3 patients.1 It is an open-label uncontrolled prospective study. In spite of the relatively early nature of the work, the work has considerable scientific merit in that the authors studied many variables, including psychological testing, lipid testing, and weight. A particularly impressive feature is the use of a respiratory chamber to assess the resting metabolic rate (RMR) over a prolonged period of time while various electrode stimulation parameters were explored. This pilot study demonstrated that no serious adverse effects and no detrimental psychological consequences were observed with continuous LHA DBS. Moreover, some weight loss trends were observed when monopolar DBS was applied via specific contacts found to increase the RMR measured in a respiratory chamber. The authors’ LHA DBS may be applied safely to humans with intractable obesity. Although these data are intriguing, there are some caveats. No adverse events were reported. However, 3 patients is a very small number on which to draw a definitive conclusion since the incidence of complications is relatively low in DBS cases. The data on efficacy are somewhat contradictory, although the results may become clearer as more patients are accrued. Intuitively, it seems that the RMR would be a good measure of efficacy. Yet the change in RMR does not seem to directly correlate with weight loss. For example, one patient (Case 1) had the greatest increase in RMR and the smallest decrease in weight, whereas another patient (Case 3) had a modest increase in RMR and yet had the greatest decrease in body weight. Hence, based on this very limited data set, RMR does not appear to be a predictor of success. In spite of these caveats, the authors are to be applauded for conducting such a thorough study. It is precisely this type of meticulous approach that will lead to progress in determining the utility of DBS in the treatment of obesity. (http://thejns.org/doi/abs/10.3171/2012.11.JNS121486) Disclosure