Isotopic Imaging for Prodromal Alzheimer's Disease

Evaluating the Performance of Isotopic Brain Imaging of Glucose Metabolism Via PET (18F-FDG) and Perfusion SPECT (99mTc-ECD) for the Diagnosis of Prodromal Stage Alzheimer's Disease

The primary objective of this study is to characterize cerebral metabolism modifications using 18F-FDG PET technology and perfusion with 99MTC-ECD SPECT in patients with prodromal Alzheimer's Disease drawn from a high risk population. We also compare PET and SPECT imaging within this framework, and search for optimal diagnostic thresholds.

Inclusion Criteria for the group with memory problems:

• patient consulting for memory problems
• caucasian
• memory complaint is validated by a clinical evaluation
• cognitive performance is sufficiently well preserved so that a diagnostic of dementia cannot be made (according to the DSM-IV-R and NINCDS-ADRDA criteria) at the time of inclusion
• the patient speaks French
• presence of an informant
• accepts to sign consent

Inclusion Criteria for the group without memory problems (reference population):

• at least four years of formal education
• patient consulting for memory problems
• memory problem reported by the patient is not validated by the consultation, nor by the battery of tests specified during screening
• presence of an informant
• Clinical Dementia Rating (CDR) = 0
• accepts to sign consent

Exclusion Criteria:

• Instrumental Activities of Daily Living (IADL): at least two items > 1
• Anticholinesterasic treatments and/or memantin before study inclusion
• major depressive syndrome, according to the Global Depressive Scale
• Known neurodegenerative disease or general disease or major physical problems that could interfere with cognitive functioning and testing
• Pathology that might lead to death in the short term (evolving cancer, non stable cardiopathy, hepatic, renal or respiratory insufficiency)
• contra-indications for MRI, PET or SPECT scans
• not affiliated with a social security regimen