Testing spinal stimulation for freezing while walking

Inclusion Criteria: * Age:40-85 years old. * Patients with primary Parkinson\'s disease who have been diagnosed by a movement disorder specialist for more than 5 years. Although they have a clear response to drugs, they have a frozen gait that cannot be controlled by drugs. Lower limb pain may be present with or without Parkinson\'s non-motor symptoms. * No other secondary gait problems. Exclusion Criteria: * Atypical Parkinson's disease. * Patients with spinal cord injuries. * Medication-controlled frozen gait. * It is expected that there are lesions near the implantation area causing spinal canal stenosis or myelopathy (can be ruled out by MRI). * It is expected that the implantation area has undergone previous surgery or there is infection near the implantation area, which may affect the success rate of implantation or increase concerns about complications (such as severe extraspinal adhesion, or spinal cord damage in previous surgeries). * People with abnormal coagulation function (such as hemophilia patients) or those who have been controlled by long-term use of antithrombotic drugs and cannot stop taking them in a short period of time. * CDR (Clinical Dementia Rating Scale) ≧2. 8. Those who are allergic to developer.