Deep brain stimulation for Parkinson's disease: patient selection and motor outcomes

DBS is a safe and effective option for the treatment of patients with advanced PD. To ensure a successful outcome, however, it is important to select the appropriate candidates. The ideal candidate has idiopathic PD, suffers from complications of chronic levodopa therapy despite optimal medical management, and has no cognitive impairment or active psychiatric issues. Although the exact mechanism of how DBS exerts its effects remains under investigation, it is clearly apparent that bilateral stimulation of either the GPi or STN effectively helps the motor symptoms of PD. While many surgical centers favor stimulation of the STN over the GPi, there is accumulating evidence that STN stimulation may result in adverse non-motor outcomes such as depression. Future studies will be needed in order to determine the best site of stimulation, the exact mechanisms of DBS, and the long-term outcomes of both motor and non-motor symptoms. As our understanding of these components becomes clearer, we will be able to optimize the treatment and management for those whose lives are affected by Parkinson's disease.