Deep Brain Stimulation in Parkinson’s Disease

Subthalamic deep brain stimulation (STN DBS) is an established treatment for the motor symptoms in patients with advanced Parkinson’s disease (PD). In addition to improvements in motor symptoms, many studies have reported changes in various nonmotor symptoms (NMSs) after STN DBS in patients with PD. Psychiatric symptoms, including depression, apathy, anxiety, and impulsivity, can wo-rsen or improve depending on the electrical stimu-lation parameters, the locations of the stimulating contacts within the STN, and changes in medica-tions after surgery. Global cognitive function is not af-fected by STN DBS, and there is no increase in the incidence of dementia after STN DBS compared to that after medical treatment, although clinically in-significant declines in verbal fluency have been con-sistently reported. Pain, especially PD-related pain, improves with STN DBS. Evidence regarding the effects of STN DBS on autonomic symptoms and sleep-related problems is limited and remains con-flicting. Many symptoms of nonmotor fluctuations, which are occasionally more troublesome than mo-tor fluctuations, improve with STN DBS. Although it is clear that NMSs are not target symptoms for STN DBS, NMSs have a strong influence on the quality of life of patients with PD, and clinicians sh-ould thus be aware of these NMSs when deciding whether to perform surgery and should pay atten-tion to changes in these symptoms after STN DBS to ensure the optimal care for patients