Vlassenko AG, Couture L, Goate AM, Raichle ME, Morris JC, Mintun MA.
Regional brain metabolism in cognitively normal elder individuals with various levels of cerebral beta-amyloid deposition.
Human Amyloid Imaging 2011 Meeting Abstracts. 2011 Jan 15;
The concept of preclinical Alzheimer's disease (AD) implies that beta-amyloid (As) deposits may accumulate in the
brain years prior to the clinical manifestations of AD. In this study, we analyzed whether clinically asymptomatic
As deposition is associated with regional changes in the metabolic state of the brain. Twenty one cognitively
normal individuals (mean age 74 years old) underwent [18F] fluorodeoxyglucose PET scan to measure the relative
cerebral metabolic rate of glucose and 15O-labeled CO, OO, and H2O scans to measure the relative metabolic rate
of oxygen. An image of aerobic glycolysis, expressed as glycolytic index (GI), was created using linear regression
between cerebral metabolic rates of oxygen and glucose. All individuals also underwent [11C]PIB PET scans and
binding potentials were evaluated in MRI-defined brain regions. Mean cortical binding potential (MCBP) was
calculated from four representative regions and used as a global measure of brain As deposition (with 0.18 as a
threshold level). As deposition was low (MCBP