Testing brain stimulation for movement and other symptoms

Inclusion Criteria: * Aged 50-85 years, male or female. * Diagnosed with "clinically established" or "clinically probable" Parkinson's disease according to the 2015 MDS Clinical Diagnostic Criteria for Parkinson's Disease. * Hoehn-Yahr stage ≥ 2, and judged by the investigator to be able to cooperate in completing scale-based assessments and MRI examinations. * Stable regimen of anti-Parkinsonian medication for at least 4 weeks before enrollment, and agreement to maintain a stable regimen during the main study phase unless medically necessary to change. * Written informed consent signed by the study participant. Exclusion Criteria: * Non-primary Parkinson's disease or other parkinsonism / atypical parkinsonism. * Previous receipt of invasive neuromodulation therapies such as deep brain stimulation (DBS) or other intracranial implantation/stereotactic brain surgery. * Presence of contraindications or high-risk conditions for transcranial electrical stimulation (e.g., incompatible metal implants/implantable electrical stimulation devices, etc.), or judged by the investigator as unsuitable to receive transcranial electrical stimulation. * Receipt of non-invasive neuromodulation interventions such as transcranial magnetic stimulation or transcranial electrical stimulation within the past six months. * Presence of contraindications to MRI or inability to tolerate MRI examination. * Significant cognitive impairment or severe psychiatric symptoms that prevent completion of assessments or result in poor compliance. * New initiation or dose adjustment of medications or treatments that significantly affect sleep architecture/consciousness status within the past 4 weeks. * History of epilepsy. * Pregnancy or breastfeeding. * Any other condition judged by the investigator as unsuitable for participation in the study.