Is there a specific memory signature associated with A β-PET positivity in patients with amnestic mild cognitive impairment?

We examined whether a positive ([18F]Florbetapir) beta amyloid positron emission tomography scan, supporting underlying Alzheimer's disease pathophysiology, was associated with specific memory deficits in 48 patients with aMCI (33 beta amyloid positive, 15 beta amyloid negative). Memory was evaluated using an autobiographical fluency task and a word-list learning task with 2 different encoding types (shallow/incidental versus deep/intentional). Compared with 40 beta amyloid-negative controls, both aMCI subgroups demonstrated severe deficits in the global memory score and in most subscores of both tasks. Finer-grained analyses of memory tests showed subtle association with beta amyloid status, revealing a stronger impairment of the primacy effect in beta amyloid-positive patients. Structural magnetic resonance imaging showed that both aMCI subgroups exhibited comparable atrophy patterns, with similar degrees of medial temporal volume loss compared with controls. Specifically assessing the primacy effect might complement global memory scores in identifying beta amyloid-positive patients with aMCI.
PMID: 30784816 [PubMed - as supplied by publisher]

Source: Neurobiology of Aging - January 31, 2019 Category: Geriatrics Authors: Tomadesso C, Gonneaud J, Egret S, Perrotin A, Pélerin A, de Flores R, de la Sayette V, Desgranges B, Chételat G, La Joie R Tags: Neurobiol Aging Source Type: research