119). A power calculation suggests that 87 additional DBS subjects would be required to show a significant weight gain at an average follow-up of 1 year after the staged bilateral surgery, supporting a trend for modest additional weight gain following staged placement of a second STN DBS

electrode. Figure 1 (A) Weight gain (mean ± SEM) for both MG-132 supplier unilateral and bilateral STN DBS patients is statistically significant at 24 months when compared with PD controls without DBS. A smaller weight gain occurred in the staged bilateral DBS patients following … The majority of the weight gain in the STN DBS Inhibitors,research,lifescience,medical patients occurred in the first six months after the initial electrode placement in both the unilateral STN DBS patients Inhibitors,research,lifescience,medical and the staged bilateral STN DBS patients.

There was a trend toward weight loss in the unilateral patients while weight gain persisted in the staged bilateral patients over the 1- to 2-year postoperative interval. The maximum amount of weight gained by a unilateral STN DBS case at 2 years postoperatively was 20.5 kg, and a greater than 10 kg weight gain occurred in three unilateral cases (20%). The maximum amount of weight gained by a staged bilateral STN DBS case at 2 years postoperatively was 20 kg, and greater than 10 kg weight gain occurred in four staged bilateral cases (25%). Weight gain of 10 kg or greater did not occur in any Inhibitors,research,lifescience,medical of the controls at 2 years, while weight loss occurred over a 2-year interval in 50% of the controls versus only 25% and 18% of the unilateral and staged bilateral STN DBS patients Inhibitors,research,lifescience,medical (P < 0.001, respectively, unilateral and staged bilateral STN DBS patients vs. controls, Table 1). Quantitative changes in weight were similar between men and women in the DBS and control groups. Male cases gained an average of 5.07 ± 1.65 kg compared to male controls who lost 0.88 ± 1.10 kg. Female cases gained an average of 4.04 ± 3.06 kg compared to a Inhibitors,research,lifescience,medical loss of -0.38 ± 2.79 kg for female controls. There were no significant differences in weight change between the cases and controls by gender (males

gained 5.95 kg more between cases and controls compared to 4.42 kg for females). Additionally, no significant relationship was noted between the initial side for STN DBS surgery and weight gain. Table 1 Interestingly, we found that the patients who underwent staged bilateral surgery within many 2 years of their initial electrode placement weighed an average of 10.2 kg (22.4 lbs.) less at baseline than both the patients who remained unilateral at 2 years and the PD controls without DBS (P < 0.0001 and P < 0.0001, respectively). Indeed, two patients (9%) among the staged bilateral STN DBS group were underweight by the NHLBI BMI criteria preoperatively versus none of the unilateral STN DBS patients or the controls without DBS.