Bilateral subthalamic deep brain stimulation after bilateral pallidal deep brain stimulation for Parkinson's disease.

BACKGROUND/OBJECTIVE: Globus pallidus internus (GPi) and subthalamic nucleus (STN) have successfully been targeted independently for deep brain stimulator (DBS) placement in medically intractable Parkinson's disease (PD). Bilateral implantation of STN DBS in a patient with preexisting, functioning GPi DBS to specifically treat motor fluctuations is, to our knowledge, yet unreported. CLINICAL PRESENTATION: We present a case of PD who had well-placed bilateral GPi DBS that controlled dyskinesia effectively and improved the motor symptoms like rigidity and akinesia. It did not improve her motor fluctuations and failed to reduce her medications. METHODS: We implanted bilateral STN DBS, which improved her 'on' time, reduced her medications and improved her motor scores. RESULTS/CONCLUSION: In this report we discuss the rationale, technical issues, programming nuances and outcome in a patient with preexisting bilateral GPi DBS who was implanted with bilateral STN DBS.