Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Progressive Supranuclear Palsy ?
    ### Response:
    Progressive supranuclear palsy (PSP) is a rare brain disease. It affects brain cells that control the movement of your eyes. This leads to serious and permanent problems with balance and the way you walk. It usually occurs in middle-aged or elderly people. Symptoms are very different in each person, but may include personality changes, speech, vision and swallowing problems.
    