This study is for people with Parkinson's disease who feel a lack of motivation, called apathy. Researchers want to try a new method called repetitive transcranial magnetic stimulation (rTMS). It's a way to send tiny magnetic pulses to the brain to help improve motivation. This special type of rTMS is called accelerated intermittent theta-burst stimulation (iTBS), and it targets a specific brain area known as the dorsomedial prefrontal cortex (dmPFC).

Participants will visit the study site six times over two weeks. Each visit will include eight short sessions of iTBS. Researchers will check how well participants stick to the schedule and how they feel after the treatment. They'll also use tools like fMRI (a brain scan) and EEG (measures brain activity) to see if the treatment changes the brain.

• Study duration: 2 weeks with follow-ups at 2 and 4 weeks post-treatment.
• Participants must be 45-85 years old with stable Parkinson's medications.
• Excludes individuals with severe cognitive issues or certain psychiatric conditions.