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P1‐365: Refined Semantic Memory Assessment Can Potentially Improve Clinical Diagnosis of Preclinical Alzheimer’s Disease
Author(s) -
Carta Caroline,
De Marco Matteo,
Venneri Annalena
Publication year - 2016
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2016.06.1117
Subject(s) - frontotemporal dementia , semantic memory , executive functions , psychology , semantic dementia , dementia , disease , clinical dementia rating , executive dysfunction , audiology , voxel , cognitive impairment , cognition , cognitive psychology , medicine , neuropsychology , pathology , neuroscience , radiology
Background:With emerging interventions targeting the early stages of Alzheimer’s disease (AD), refinement of early diagnosis is a priority in dementia research. Although clinical testing offers high diagnostic accuracy during the advanced stages of the disease, its sensitivity is insufficient in detecting subtle cognitive changes during the preclinical stage. This study aims to modify a clinical instrument to explore the nature of semantic memory impairment which appear very early in AD and to test its anatomical validity.Methods: A modified version of the confrontation naming task (CNT) was used for the testing of the automatic and executive aspects of semantic memory. The test contained 40 novel photographed pictures. Half of the pictures consisted of whole objects (automatic) while the other half contained part of an object (executive). The tests were administered to 13 healthy controls (HC) and 13 patients (9 prodromal AD, 4 frontotemporal dementia (FTD)). Twentyseven participants (20 healthy and 7 patients) also had a 3D structural MRI scan. A regression model was run to establish the grey matter correlates of the automatic and executive components. Results:A significant main effect was observed for group on the total score of the test where the worst score was presented by the FTD group and the optimal score by HC. A significant effect was also present for the type of task. HC and FTD performed similarly in both the automatic and executive tasks, Prodromal AD performed worse in the latter. Voxel based morphometry data suggest that higher scores on the executive subtest were associated with higher GM density in the inferior frontal and superior temporal gyri while the automatic subtest-scores were positively associated with the medial limbic system and superior and medial frontal gyri. Conclusions: These tests contribute to the understanding of the memory impairment in preclinical AD and might be useful in detecting abnormalities earlier than current tests allow. Earlier detection of abnormal changes will positively impact on possible recruitment of more homogenous participants in clinical drug trials which in turn might result in a more effective testing of treatment efficacy.