Deep brain stimulation (DBS) is a well-established therapy for treating neurological movement disorders. Some patients who have received DBS therapy have noticed significant weight gain. Further investigation into correlations between patient characteristics and weight gain following DBS device implantation, which the authors here have done, will provide physicians with useful clinical information.
The authors performed a retrospective study of patients with Parkinson’s disease (PD) and essential tremor (ET) who had received DBS therapy in the period from 2012 to 2017. Patient weights had been recorded preoperatively and at 3, 6, and 12 months postoperatively. These data were used to compare patient characteristics, including diagnosis, body mass index (BMI), sex, levodopa equivalent dose (LED), and change in Unified Parkinson’s Disease Rating Scale (UPDRS) score. For PD patients, a quantile multivariate regression analysis was used to examine whether significant correlations existed between several of these patient characteristics, as well as age and weight gain following implantation.
PD patients had gained a significant amount of weight at 3 months (mean [SE] 2.66 [0.428] kg, p < 0.001), 6 months (3.64 [0.492] kg, p < 0.001), and 12 months (4.18 [0.540] kg, p < 0.001) after DBS placement. Patients who had undergone subthalamic nucleus (STN) DBS device placement gained, on average, more weight than the patients with globus pallidus internus (GPi) placement at both 6 months (mean 2.558 [1.020] kg, p = 0.01) and 12 months (2.358 [1.130] kg, p = 0.04). BMI in the STN cohort was greater than that in the GPi cohort at 6 months (mean difference [SE] 2.60 [1.127] kg/m2, p = 0.02) and at 12 months (2.36 [1.112] kg/m2, p = 0.04). A reduction in LED was negatively correlated with weight change at 6 months (r = −0.33, p < 0.001) and 12 months (r = −0.41, p < 0.001). There was no weight gain correlated with DBS therapy for ET.
PD patients experienced a significant change in weight over time after DBS therapy, whereas ET patients did not. PD patients with an STN target site experienced greater weight gain, on average, than those with a GPi target site. Furthermore, there was a significant increase in BMI at 6 and 12 months in patients with an STN target compared to that in patients with a GPi target. PD patients whose LED was reduced after DBS gained more weight at 6 and 12 months after surgery than the patients whose LED was kept at the same level or increased.