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 disorder that causes serious and progressive problems with control of gait and balance, along with complex eye movement and thinking problems. One of the classic signs of the disease is an inability to aim the eyes properly, which occurs because of lesions in the area of the brain that coordinates eye movements.
    