The purpose of this study is to evaluate several different tests, including brain imaging, eye movement testing, body fluid samples, measurements of memory and other thinking abilities, and measures of functional independence in the hope that this information can be used to guide diagnosis and treatment of PSP and CBD in the future. Recent advances in our understanding of the biological causes of these diseases offer hope for new treatments. As such treatments are developed, sensitive and specific biological measurements (biomarkers) will be needed to provide precise and direct measures of the state of the brain, which will improve the statistical power of clinical trials. Brain imaging with Magnetic Resonance Imaging (MRI) has previously been used to measure disease-related changes in the brain. The goal of this study is to identify the best methods of analysis (including eye movements, imaging, and behavioral measures) for tracking PSP and CBD over time. In addition, certain biomarkers in the blood and cerebrospinal fluid might also be useful for following these diseases over time. This study will examine the value of blood and CSF biomarkers relative to brain imaging and functional measures.

Inclusion Criteria:

• Clinical diagnosis of Progressive Supranuclear Palsy or Corticobasal Degeneration
• Must have a reliable study partner who has frequent contact with the subject
• Willing and able to undergo testing procedures

Exclusion Criteria:

• Significant neurological disease other than PSP or CBD
• Presence of pacemakers, aneurysm clips, artificial heart valves, ear implants, metal fragments or foreign objects in the eyes, skin or body

Subjects with a diagnosis of PSP or CBD