**Study Summary:** This study looks at a protein called *tau* in the brains of people with *Progressive Supranuclear Palsy* (PSP). PSP is a brain disorder that affects movement, balance, and eye movements. The study uses special imaging techniques to see how much tau is in the brain. **Eligibility:** - **Who can join?** People over 35 with PSP symptoms that are getting worse. - **Who can't join?** People with other brain diseases like Alzheimer's or Parkinson's, certain health conditions, or who are pregnant or breastfeeding. **Important Points to Consider:** - **Visits:** The study might involve several visits for imaging tests. - **Risks:** If you have metal in your body or certain health conditions, you might not be able to join because of risks with imaging tests. - **Compensation:** The study may provide compensation for participation, but it's important to check with the study team. Before deciding to join, talk with your doctor and loved ones to make sure it's the right choice for you. Always ensure you understand the study's requirements and potential risks.