Association between subthalamic nucleus deep brain stimulation and weight gain: Results of a case–control study

• Patients with PD have been shown to lose weight over the course of their disease.
• Weight gain has been reported in PD patients after deep brain stimulation (DBS).
• In this study, PD cases gained weight while controls not undergoing DBS lost weight.
• This weight gain may be normative and further prospective study is needed.

ObjectiveTo evaluate whether weight change in patients with Parkinson's disease (PD) is different in those undergoing deep brain stimulation (DBS) of the subthalamic nucleus (STN) compared to those not undergoing DBS.Patients and methodsA retrospective case–control study was performed in PD patients who had undergone STN DBS (cases) compared to matched PD patients without DBS (controls). Demographic and clinical data including Unified Parkinson's Disease Rating Scale (UPDRS) motor scores were collected. Repeated measures mixed model regression was used to identify variables associated with weight gain.ResultsThirty-five cases and 34 controls were identified. Baseline age, gender, diagnosis and weight were similar. Duration of diagnosis was longer in cases (6.3 vs 4.9 years, p = 0.0015). At 21.3 months, cases gained 2.9 kg (+4.65%) while controls lost 1.8 kg (−3.05%, p < 0.02). Postoperative UPDRS motor scores improved by 49% indicating surgical efficacy. Only younger age (p = 0.0002) and DBS (p = 0.008) were significantly associated with weight gain.ConclusionIn this case–control study, PD patients undergoing STN DBS experienced post-operative weight gain that was significantly different from the weight loss observed in non-DBS PD controls. Patients, especially overweight individuals, should be informed that STN DBS can result in weight gain.