This study is investigating a new method called **Temporal Interference Stimulation (TIS)** to help people with Parkinson's disease, a condition affecting movement and speech. TIS is a type of brain stimulation targeting the **subthalamic nuclei** - tiny brain areas involved in movement control. Two groups will be compared: one group receives TIS with different frequencies on each side of the brain (130 Hz and 60 Hz), while the other group gets the same frequency on both sides (130 Hz). Researchers will use **functional magnetic resonance imaging (fMRI)** to see how the brain changes with TIS. **Key Points:** - The study involves a 5-day course of TIS treatment with follow-up assessments. - Participants must have mild to moderate Parkinson's and stable medication. - The study will measure effects on movement and speech, using fMRI for brain activity analysis. Participants will undergo brain scans and evaluations before and after the intervention. Any discomfort or side effects will be recorded. This study aims to find out if the new TIS method can better improve movement and speech issues in Parkinson's disease compared to the standard method.