The investigators propose to study persons with Parkinson Disease (PD) with detailed clinical, cognitive and imaging at the time of study entry and repeat these assessments 2 years later. The study looks at how changes in activity of the neurotransmitter acetylcholine relates to changes in cognitive function and to see if there is presence or build up of amyloid protein.

Participants with PD will be studied at initial visit assessing clinical, cognitive, and brain imaging. A one year and, if applicable, three year cognitive assessment will be done, and the entire/complete assessment (same as initial visit) will be repeated again at two years. There will be a maximum of three follow up visits. The imaging test battery will consist of amyloid and acetylcholine brain PET and MRI scans. The use of acetylcholine PET imaging will demonstrate how changes in activity of this neurotransmitter relate to changes in cognitive functions, such as memory and mental concentration. A key question will be whether persons with PD who not only are losing acetylcholine brain cells but also have the buildup of the Alzheimer amyloid protein have a more rapid progression with more severe cognitive decline and behavioral changes compared to persons who do not have the amyloid protein.

Inclusion Criteria:

PD diagnosis according to the UK PD Society of Brain Bank research Center criteria PD subjects at risk for dementia Age 50 and above, male or female Absence of dementia confirmed by clinical and detailed neurological assessment -

Exclusion Criteria:

Subjects with contra-indications to MR imaging Evidence of large vessel stroke or mass on on MRI Use of cholinergic or neuroleptic drugs at baseline Evidence of atypical parkinsonism on neurological exam Subjects limited by participation in research procedures involving ionizing radiation Pregnancy(test within 48 hours of each PET session) or breastfeeding

-

UM and VA Movement Disorders Clinic

Primary Care Clinic

Community