Overweight after deep brain stimulation of the subthalamic nucleus in Parkinson's disease: long-term follow-up.

OBJECTIVE: To assess the occurrence of weight gain in parkinsonian patients with an average sixteen months follow-up after subthalamic nucleus deep brain stimulation. METHODS: We used dual X-ray absorptiometry to evaluate changes in body weight and body composition in 22 parkinsonian patients (15 men and 7 women) before surgery, three months after surgery and on average sixteen months after surgery. RESULTS: No patient was underweight before surgery and 50% were overweight. By contrast, 68% were overweight or obese three months after surgery and 82% after sixteen months (p<0.001). For the men, the mean increase of the BMI was 1.14+/-0.23 kg/m2 three months after surgery and 2.02+/-0.36 kg/m2 16 months after surgery. For the women the mean increase of the BMI at the same evaluation time was 1.04+/-0.30 kg/m2 and 2.11+/-0.49 kg/m2. This weight gain was mainly secondary to fat mass increase in both men and women. Three months after surgery, acute subthalamic deep brain stimulation induced an improvement on parkinsonian symptoms (evaluated by the UPDRS Part III) by 60.7+/-2.9% in the "off" dopa condition and a dramatic improvement of motor complications (dyskinesia duration: 82.8+/-12.8%, p<0.0001; Off period duration: 92.7+/-18.8%, p<0.0001). CONCLUSION: Although subthalamic nucleus deep brain stimulation significantly improved the parkinsonian symptoms and motor complications, many patients became overweight or obese. This finding highlights the necessity to understand the underlying mechanisms and to provide a diet management with a physical training schedule appropriated for parkinsonian patients.