Can focused electrical fields deep in the brain ease Parkinson's tremors?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age 18-75 years (inclusive), any gender. * Diagnosis of idiopathic Parkinson's disease according to the Chinese diagnostic criteria for Parkinson's disease (2016 edition). * Hoehn and Yahr stage 2-4 (inclusive) during the "off" state. * Documented response to levodopa (\>33% improvement), with a stable anti-parkinsonian medication regimen for at least 4 weeks prior to screening, and no dose adjustments during the study. * Voluntary signed informed consent, and ability to understand and comply with the study protocol to complete the study. * No significant cognitive impairment (Montreal Cognitive Assessment \[MoCA\] score ≥21). Exclusion Criteria: Inability or unwillingness to comply with the study protocol and/or inability to provide written informed consent; Presence of a significant medical condition that may interfere with study procedures or confound the assessment of study endpoints; Presence of a severe psychiatric disorder that may affect the participant's ability to comply with the study protocol; A history of psychiatric disorders or current severe depression or anxiety; Presence of metallic implants in the brain; Known pregnancy or current breastfeeding; Severe neurological disorders, such as a brain tumor; Severe cardiac disease, including the presence of an implanted cardiac pacemaker; Scalp lesions, inflammation, infection, active bleeding, or an increased bleeding tendency; Any other current medical condition for which the use of transcranial electrical stimulation may pose an unacceptable risk; A history of epilepsy or structural brain lesions, including severe cerebral atrophy or cerebrovascular disease; Inability to undergo magnetic resonance imaging (MRI), such as because of claustrophobia or implanted metallic devices; Inability to cooperate with or complete the required assessments; or any other condition that, in the investigator's judgment, makes the individual unsuitable for participation in the study.