This study focuses on Parkinson's disease (PD), which is a condition affecting movement and other body functions. The study compares a new method, STN-tTIS (subthalamic nucleus-targeted transcranial temporal interference stimulation), with traditional medication for PD. STN-tTIS is a non-surgical way to stimulate the brain to help improve movement symptoms. The study aims to see if different frequencies of STN-tTIS (once, twice, or five times a week) work better than just medication and how long the effects last. Participants will be randomly assigned to receive either STN-tTIS or continue with their regular PD medication for two weeks. They will be checked for symptoms and other health aspects during and after the treatment.

• The study lasts 4 weeks in total: 2 weeks of treatment and 2 weeks of follow-up.
• Participants will either receive STN-tTIS or their usual medication.
• Assessment includes both movement and non-movement symptoms.