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O2‐04‐03: Distinct Spatial Navigation Impairment Across Neurodegenerative Dementias and its Neuroanatomical Underpinnings
Author(s) -
Nedelska Zuzana,
Laczo Jan,
Uller Miroslav,
Vlcek Kamil,
Vyhnalek Martin,
Obenberger Jiri,
Parizkova Martina,
Hort Jakob
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.2016.06.413
Subject(s) - dementia , frontotemporal dementia , psychology , atrophy , dementia with lewy bodies , audiology , progressive supranuclear palsy , spatial memory , neuroscience , posterior cortical atrophy , disease , medicine , cognition , pathology , working memory
decline is increased substantially by the presence of at least one copy of the APOE ε4 allele. Despite advances in Ab biomarkers, age remains the greatest risk factor for dementia, particularly Alzheimer’s disease (AD). As APOE ε4 increases risk for Ab+ and older adults are also more likely to be Ab+, it is important to understand the extent to which age influences the effects of ε4 on Ab+ related memory decline. This study aimed to determine the extent towhich theAPOE ε4 allele influenced Ab related cognitive change in adults aged between 60-74 and 75-90 years old. Methods:Nondemented adults (n1⁄4485) enrolled in the AIBL study underwent Ab neuroimaging and ε4 genotyping. Episodic Memory was assessed at baseline, 18-, 36-, 54and 72-month follow-ups. Participants were classified as Abor Ab+ using PET neuroimaging and into two age groups (<75 and 75) according to their age at baseline. Data were analysed using linear mixed model analyses. Results:In adults aged<75, when compared to the Abgroup, there was a significant rate of memory decline only in Ab+ ε4 carriers (d1⁄41.25). In adults aged 75, when compared to the Abgroup, both Ab+ ε4 carriers (d1⁄41.23) and non-carriers (d1⁄40.35) showed significant rates of memory; however, the memory decline in Ab+ ε4 carriers was substantially greater when compared to noncarriers (d1⁄40.82). This faster rate of memory decline in adults aged 75 was reflected in a 43% of Ab+ ε4 carriers meeting clinical criteria for dementia at the 72-month assessment, in contrast to just 24% of Ab+ ε4 non-carriers and 10% of Abparticipants. Conclusions:Previous studies investigating the relationship between ε4 andAb+have not accounted for potential non-linear effects of age on memory decline. The rate of Ab+ related memory decline was greatest in adults aged 75, particularly in those who were also APOE ε4 carriers. This suggests that the combined effects of Ab+ and ε4 on risk for dementia increases substantially in older adults.