Distinguishing Between Alzheimer's Disease, Lewy Body Dementia, and Parkinson's Disease

The study will use structural and functional MRIs, daTscans, fluorodeoxyglucose (FDG) PET
scans, Amyvid PET scans, polysomnographs, neuropsychological testing, cerebrospinal fluid in
willing participants to distinguish between a diagnosis of Alzheimer's disease, Lewy Body
dementia, and Parkinson's Disease. All subjects will have a clinical evaluation, physical
examination including vital signs and orthostatic blood pressures and pulses, neurological
examination including UPDRS evaluation, genetic blood sample collection, neuropsychological
testing, polysomnogram, and neuroimaging. The study partner will also be interviewed for
completion of all of the behavioral and functional measures.

Inclusion Criteria:

- Subjects must meet the standard clinical criteria of the syndromes of interest

- All subjects must have enough cognitive abilities to complete study procedures, which
will be operationally defined as having a Mini Mental State Examination (MMSE) score
greater or equal to 10.

- Subjects must be on stable cognitive and psychoactive medication regimen for the
preceding four weeks of enrollment.

- Subjects must have a responsible study partner that either lives with them or is in
regular contact with them at least 4 out of 7 days per week.

- Subjects must have visual and auditory acuity adequate for testing.

Exclusion Criteria:

- Any other condition (other than the primary diagnosis), which in the opinion of the
investigators might contribute to the syndrome of dementia or complicate its
assessment.

- active medical disorder that could preclude participation in this protocol

- Women who are pregnant or are breast feeding

- severe renal impairment as defined by glomerular filtration rate (GFR) less than 30
(may have increased radiation exposure with the DaTscan).

- Subjects in whom English is not the 1st language

- Subjects with educational level less than 12 years

- Subjects who have ever participated in an experimental study with an amyloid targeting
agent unless it can be documented that the subject received only placebo during the
course of the trial.