The Impacts of Deep Brain Stimulation on Dual-task Gait Performance in Parkinson's Disease: Focusing on Long-term Outcome and the Effects of Stimulation Modes

Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease. Motor symptoms include rigidity, bradykinesia, tremor, and postural instability, these motor symptoms can cause gait dysfunction. Non-motor symptoms include depression, dysarthria, cognitive disability, and sleep disturbance. Although these symptoms can be improved through drug treatment, when the course of PD reaches the middle to late stage, it will still face the situation of weakened drug efficacy and the drug side effects increased. When medication can no longer adequately control the motor symptoms of PD, deep brain stimulation (DBS) becomes a powerful option. DBS is a surgical treatment that involves implanting one or more electrodes into specific areas of the brain, which deliver electrical stimulation to regulate or destroy abnormal neural signal patterns in the target area. The effect of DBS has been proven whether it is in improving motor-related symptoms or non-motor-related symptoms, but there are still some areas that have not been compared before and after the surgery, such as: gait variability, executive functions and dual-task walking. In addition, the parameters of electrical stimulation for DBS will also affect the clinical characteristics of patients. Due to the large difference between individual cases, the recommendation of the electrical stimulation frequency still not be established. Therefore, the influence of DBS and its parameters on the symptoms of PD is a topic worthy of discussion. Purposes: (1) To investigate the long-term effects of DBS on the symptoms of PD. (2) To investigate the effects of DBS stimulation frequencies on walking performance and executive function in individuals with PD.