Deep brain stimulation of the subthalamic nucleus (STN-DBS) constitutes the mainstay treatment in advanced Parkinson’s disease (PD) with motor fluctuations. Despite its efficacy on motor signs and quality of life, emergent adverse events have been recently reported. Among them, weight gain (WG) is a recognized adverse event of subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson‘s disease (PD). Also, WG is poorly known at the long-term and predisposing factors have not yet been identified. We conducted a cross-sectional study of WG in 47 STN-DBS PD patients between 1999–2006. Data on disease history, motor status and dopaminergic drug treatment were retrospectively collected at surgery and 1 year post-surgery. Weight at disease diagnosis and at surgery, as well as the current weight and height were gathered by an autoquestionnaire. Moreover, the weight before surgery was obtained and verified in medical files in more than 90% of our patients. Sixty-six patients who underwent surgery between 1999–2006 were included, but six were deceased, four refused to participate and nine were lost for follow-up. So, 47 (71%) were retained in our analysis. A total of 78.7% of patients gained weight. On average 4.7 years follow up after surgery, the mean weight gain was +7.2±8.1kg compared to the preoperative assessment (p<0.001) and the mean BMI gain was +2.7±3.0kg/m² compared to pre-surgery values (p<0.001). The patients gained more weight after surgery than they had lost during disease evolution before surgery. Women and patients with a more severe UPDRS-III “off” drug score before surgery significantly gained more weight. Our study provides further evidence that the WG is a problem after STN-DBS and concerns a majority of patients at the long term. It may expose them to complications that should be considered for prevention and the patient’s information before surgery.

La stimulation cérébrale profonde bilatérale du noyau sous-thalamique dans le cadre de la maladie de Parkinson s’accompagne fréquemment d’une prise de poids. L’importance de cette prise de poids à long terme est mal connue et les facteurs prédisposant ne sont pas identifiés. Nous avons mené une étude rétrospective auprès de 47 patients opérés dans ce cadre entre 1999–2006. Cette prise de poids concerne 78,7 % des patients opérés. Sur un suivi moyen 4,7ans après l’intervention, la prise de poids moyenne était de +7,2±8,1kg par rapport à l’évaluation préopératoire. (p<0,001). Les femmes et les patients avec un UPDRS III-score de drogue « off » plus sévère avant la chirurgie sont les sujets qui prennent significativement plus de poids.