Amyloid Plaque and Tangle Imaging in Alzheimer's Disease and Down Syndrome

The purpose of this study is to develop small molecule radio-labeled probes of beta-amyloid, to be used with positron emission tomography (PET) for early detection and treatment monitoring of Alzheimer disease (AD). The study hypothesis is that PET imaging of small molecule probes, in the form of novel fluorescent dyes with radioactive labels, will demonstrate cerebral patterns in patients with AD that are distinct from those of age-matched persons who are cognitively intact.

This is a naturalistic study in which clinical evaluations and brain scans will be performed on 20 people with Down syndrome (DS) as well as 20 healthy controls across a range of ages. Participants will receive comprehensive clinical and neuropsychological assessments. PET and MRI scans will be performed at baseline and after two years of follow up. All participants will have blood drawn for APOE genotyping during their baseline evaluations. The intellectual range of participants with DS will be restricted to IQ scores of 45 to 60 (moderate range) to reduce variability, particularly due to extreme low levels of intellectual ability.