Deep brain stimulation (DBS) is an efficacious neurosurgical treatment for moderate-to-late stage Parkinson's disease (PD). The subthalamic nucleus (STN) and globus pallidus interna (GPi) are two targets extensively studied and used worldwide in treating PD. Although the conventional SYMMETRIC bilateral STN and GPi DBS are shown to be effective in controlling motor symptoms such as bradykinesia, tremor, and dyskinesia, each target has its pros and cons in terms of axial symptom control, medication reduction, cognitive decline, and programming. Therefore, we speculate that an ASYMMETRIC bilateral implantation of DBS leads (i.e., combined unilateral STN and contralateral GPi DBS) may be able to bring the greatest clinical benefits to PD patients by taking advantage of both bilateral STN and GPi DBS at the same time. The preliminary retrospective study containing eight PD patients undergoing asymmetric implantation of DBS demonstrated the safety and efficacy of this treatment strategy during short-term follow-up. This multicenter, single arm, open label study aims to prospectively investigate during the long-term follow-up the safety and efficacy of asymmetric DBS for PD in terms of motor and nonmotor symptoms, medication reduction, cognitive decline, and quality of life.
