Imaging Inflammation in Patients With Parkinson's Disease Dementia or Dementia With Lewy Bodies

This study is being done to see if 11C-PBR28 could be useful in diffuse Lewy body disease.
Diffuse Lewy Body Disease refers to subjects with either Parkinson's disease dementia or
dementia with Lewy bodies.

The hypothesis is that 11C-PBR28 binding will be greater in patients with diffuse Lewy body
disease than in controls, with largest differences in temporal and limbic regions of the
brain.

Participants will have a medical history and examination. This will include questions about
thinking and memory. Participants will have blood drawn for routine lab tests. Blood will
also be tested for a special genetic test to make sure the 11C-PBR28 scan will work. A
special genetic blood test will also be done to see if participants have genes that are
associated with dementia with Lewy bodies or other causes of dementia. Participants will not
receive the results of these special genetic tests. Participants will also have a magnetic
resonance imaging (MRI) scan of the brain.

If a participant still meet the inclusion and exclusion criteria after these procedures are
done, then the participant will have one PET scan using 11C-PBR28. This scan will take place
at the Columbia University Medical Center Kreitchman PET Center. On the day of the PET scan
you will have an intravenous (IV) catheter (tube) placed in the participant's arm. The
participant will also have an arterial catheter placed in an artery of your wrist.
Participant will be asked to lay down on a PET scanner. A CT scan will be taken of the
participant's head. A small amount of 11C-PBR28 will be injected into the IV. A member of the
study team will draw blood from the arterial catheter. The PET scan will last 90 minutes. The
participant will be asked to lay still during the scan.

The amount of radiation from the 11C-PBR28 PET scan is up to 20 millicuries. Similar amounts
of 11C-PBR28 have been given to over 100 human subjects in prior studies.

Inclusion Criteria:

- Inclusion criteria for patients:

1. Age 60 and older.

2. Meet criteria for either a) dementia with Lewy bodies, or b) Parkinson's disease
dementia.

3. Written and oral fluency in English.

4. Able to participate in all scheduled evaluations and to complete all required
tests and procedures.

5. In the opinion of the investigator, the subject must be considered likely to
comply with the study protocol and to have a high probability of completing the
study.

- Inclusion criteria for controls:

1. Age 60 and older.

2. Normal cognitive and motor function based on neurological examination.

3. Written and oral fluency in English.

4. Able to participate in all scheduled evaluations and to complete all required
tests and procedures.

5. In the opinion of the investigator, the subject must be considered likely to
comply with the study protocol and to have a high probability of completing the
study.

Exclusion Criteria:

1. Past or present history of certain other brain disorders.

2. Certain significant medical conditions. Examples are uncontrolled epilepsy or multiple
serious injuries.

3. Contraindication to MRI scanning.

4. Conditions precluding entry into the scanners (e.g. morbid obesity, claustrophobia,
etc.).

5. Exposure to research related radiation in the past year that, when combined with this
study, would place subjects above the allowable limits.

6. Low affinity binding on TSPO genetic screen

7. Currently taking anticoagulant drugs (e.g., warfarin).

8. Women of childbearing potential.