Objective: To provide a mechanism for recruitment and screening of AD patients for inclusion into studies conducted at the National Institutes of Health. To provide data from MRI and [18F]FDG and PIB PET imaging from healthy volunteers to compare to that from AD patients.

Study population: Patients with signs and symptoms of Alzheimer's disease. Healthy age-matched volunteers.

Design: Patients with signs and symptoms of Alzheimer's disease will be recruited from the community using advertisements and through communication with neurologists, psychiatrists, and general practitioners in the community. Patients will come to the NIH for an evaluation that may include medical and neurological evaluation, laboratory testing, brain MRI, neuropsychological evaluation, and brain imaging with [18F]fluorodeoxyglucose ([18F]FDG) and carbon-11 labeled Pittsburgh Compound B (PIB) PET. The focus of this protocol will be on assisting with the diagnosis of AD vs. another cause of memory impairment. Eligible patients will be offered participation in other protocols with the Molecular Imaging Branch. Eligible patients may also be referred to other studies at the NIH. Patients will not be offered treatment or long-term follow-up in this protocol. Age matched healthy volunteers will undergo brain imaging with MRI and with [18F]FDG and PIB PET.

Outcome measures: Results from medical and neurological evaluation, neuropsychological testing, laboratory tests, and brain MRI will be used to determine if patients meet NINDS criteria for probable Alzheimer's disease. In patients who undergo brain imaging with [18F]FDG and PIB PET, PET data will be used for investigational purposes in subjects who participate in other protocols with the Molecular Imaging Branch. Results from brain imaging from healthy volunteers will be used to compare to that from AD patients. [18F]FDG and PIB PET may also be useful for determining if patients meet criteria for probable Alzheimer's disease.