SCAN Electrical Stimulation for Parkinson's Disease

Inclusion Criteria: * Diagnosed with idiopathic Parkinson's disease (PD) according to the revised clinical diagnostic criteria of the International Movement Disorder Society (MDS) (2015 version) or the Chinese Parkinson's Disease Diagnostic Criteria (2016 version). * Age between 40 and 75 years, with a minimum age of 40 years at the time of diagnosis. * Any gender, including both male and female patients. * Hoehn-Yahr staging between 2 and 4 (inclusive). * Disease duration of 4 years or more. * Responding effectively to levodopa-based drug therapy with a minimum of 30% improvement in the levodopa loading test. * Presence of motor fluctuations with or without anisocoria despite optimal drug treatment. * Stable on medication for at least the past 1 month prior to screening and surgery. * Ability to understand the trial and willingness to sign an informed consent form. Exclusion Criteria: * Diagnosis of Parkinsonian superimposed syndrome or secondary Parkinson's disease. * Presence of intracranial structural variants or other abnormalities that may interfere with TMS or surgical treatment, as detected by MRI or CT. * Implantation of metallic medical devices such as deep brain stimulators, cochlear implants, vagus nerve stimulators, etc., which may affect MRI examination and TMS treatment. * Contraindications to MRI scanning, including claustrophobia, tattoos, or magnetic metal-containing implants (to be confirmed with specialists). * History of comorbid epilepsy or having first-degree relatives with a history of epilepsy. * Receipt of other neuromodulation treatments (e.g., TMS, transcranial electrical stimulation, transcranial ultrasound stimulation) within the 3 months prior to enrollment. * Contraindications to neurosurgery, such as bleeding or coagulation disorders. * Presence of severe organic diseases, including heart failure, renal failure, or malignancies. * Cognitive impairment as indicated by MMSE score of 24 or below. * Significant speech impairment, hearing impairment, or visual impairment that limits cooperation with testing. * Severe depression (HAMD-17 score of 24 or above) or severe anxiety (HAMA score of 29 or above). * Diagnosed psychiatric disorders based on DSM-V criteria or any psychological issues that may interfere with the study protocol. * Alcohol or substance abuse. * Active infections including hepatitis B virus (HBV), hepatitis C virus (HCV), syphilis, or human immunodeficiency virus (HIV) infection as determined by the investigator. * Any other medical abnormalities deemed by the investigator to be unsuitable for participation in the trial. * Inability to complete follow-up visits due to geographical or other reasons. * Women of childbearing age who are pregnant, breastfeeding, or intend to become pregnant during the trial. * Participation in other clinical trials concurrently.