DETECTION OF AN ALZHEIMER-DISEASE PATTERN OF CEREBRAL METABOLISM IN DOWN-SYNDROME

Correlational analysis of cerebral metabolic (rCMRglc) data obtained w ith positron emission tomography (PET) assesses group differences and has demonstrated reduced frontal-parietal rCMRglc interdependencies in Alzheimer's disease (AD). A multivariate analysis of rCMRglc data ass esses individual differences. We recently identified discriminant func tions, reflecting frontal-parietal rCMRglc interdependencies, that sep arated AD from control subjects. To test if the functions would identi fy an AD rCMRglc pattern in older Down syndrome (DS) adults with (DS D AT+) or without (DS DAT-) dementia, we applied the functions to longit udinal rCMRglc data in: young DS (n = 15), DS DAT- (n = 10), DS DAT+ ( n = 4), and young controls (n = 15). Ah DS DAT+ and some of the later DS DAT- scans were classified as AD. The results provide additional va lidation of the functions and suggest their utility for the early dete ction of AD.