MRI and PET Biomarkers for Cognitive Decline in Older Adults

This study investigates the relationship between Alzheimer's disease (AD) pathology, brain
structure and function, as well as cognition in non-demented older adults. The goal is to
develop a more complete understanding of the factors that lead to cognitive decline in the
elderly and progression to AD. The investigators will enroll 200 cognitively intact adults
between the ages of 60-85 years old from the UCI Alzheimer's Disease Research Center or
directly from the local community. Study procedures will include: 1) PET amyloid scans with
Amyvid™ radiotracer (florbetapir-F18) and PET tau scans with [18F]MK6240 radiotracer; 2)
High-resolution structural, functional, and diffusion MRI; and 3) Cognitive examinations. The
investigators will track cognitive outcomes through longitudinal monitoring. Amyloid imaging
will only be conducted once in the study at baseline, and MRI and tau PET imaging will be at
baseline and Year 1. The investigators aim to identify the best combination of tests for
predicting longitudinal cognitive/clinical decline. The proposed study will significantly
inform the understanding of cognitive decline in the aging brain and allow investigators to
better define preclinical AD and make recommendations for future intervention trials.

Inclusion Criteria:

1. Between the ages of 60 and 85;

2. Speaks fluent English;

3. Visual and auditory acuity adequate for neuropsychological and computerized testing;

4. Good general health with no disease(s) expected to interfere with the study;

5. Willing and able to participate for the duration of the study and in all study
procedures including MRI and PET;

6. Normal cognition defined as a Clinical Dementia Rating of 0 and a Mini-Mental State
Examination score of 27 or higher.

Exclusion Criteria:

1. Significant co-morbid neurologic disease such as Parkinson's disease, multiple
sclerosis, brain cyst, tumor or aneurysm;

2. Major health conditions such as uncontrolled diabetes mellitus, uncontrolled
hypertension, nutritional deficiency or uncontrolled thyroid disease;

3. Significant psychiatric disorders such as schizophrenia, bipolar disorder, anxiety
disorder, major depressive disorder, or attention-deficit hyperactivity disorder;

4. ADRC consensus diagnosis of dementia or mild cognitive impairment;

5. Cognitive impairment when tested at baseline (defined as a score on any
neuropsychological test of 1.5 SDs or more outside the age norm);

6. Alcohol or substance abuse or dependence within the past 2 years (DSM-IV criteria);

7. MRI contraindications, e.g. pacemakers, aneurysm clips, artificial heart valves, ear
implants, metal fragments or foreign objects in the eyes, skin or body. Females who
are pregnant or trying to get pregnant are also excluded;

8. PET contraindications, e.g. significant prior radiation exposure and pregnancy.