Replacement of dopaminergic medication with subthalamic nucleus stimulation in Parkinson’s disease: long-term observation

Abstract: Stimulation of the subthalamic nucleus (STN) is an effective treatment for advanced Parkinson’s disease (PD), but the medication requirements after implant are poorly known. We performed a long-term prospective evaluation of 20 patients maintained at stable dopaminergic therapy for 5 years after bilateral STN implants, who were evaluated 6 months, 1 year, 3 years, and 5 years after surgery. We mea-sured, during the entire observation period, the effect of deep brain stimulation on motor and functional outcome measures, the levodopa equivalent daily dose and the total electrical energy delivered. At 5 years, the UPDRS motor score had improved by 54.2 % and levodopa equivalent dose was reduced by 61.9%, compared with preimplant. Dopaminergic medication remained stable during the observation period, but energy was progressively increased over time. Res