PSP is a rare neurological disease that causes eye movement dysfunction, muscle rigidity, slowness of movement, swallowing, speech, emotional, cognitive and personality problems. Patients 35 to 75 years old with PSP may be eligible for this study. Candidates will be screened at the National Institutes of Health outpatient clinic in Bethesda, MD, with a medical history, physical examination, neurological and neuropsychiatric evaluations, blood tests, electrocardiogram, CT scan of the brain, and baseline studies including a special eye examination, evaluation of symptoms, lumbar puncture (spinal tap) and psychiatric interview.