Transcranial temporal interference stimulation (tTIS) is a non-invasive deep brain stimulation method. This study aims to comprehensively explore the efficacy and safety of bilateral subthalamic nucleus (STN) tTIS on motor and non-motor symptoms in patients with Parkinson's disease (PD).

This is a single-center, randomized, double-blind, sham-controlled trial for Parkinson's disease (PD). The transcranial temporal interference stimulation (tTIS) intervention period is 5 days, with follow-up assessments conducted immediately after the intervention, 10 days post-intervention, and 30 days post-intervention. The real stimulation group receives bilateral subthalamic nucleus (STN) -targeted tTIS once daily for 5 days. Stimulation parameters: carrier frequencies of 2000/2130 Hz (Δf = 130 Hz), with stimulation lasting 20 minutes on each side. Before the intervention, T1-weighted structural images are acquired for each subject, and computational modeling based on an individual head model is performed to optimize electrode placement, individually focusing on the target side STN region. The sham group follows the same procedure but does not receive effective stimulation. The sham stimulation group receives only 30 seconds of fade-in/fade-out current at the beginning and end of the stimulation period to ensure blinding.

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.