Poster C35, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Different Functional Neural Correlates of Executive Deficits in Amnestic Mild Cognitive Impairment according to High and Low Beta-amyloid Burden
Eun Hyun Seo1, IL Han Choo2; 1Chosun University, Gwangju, Korea, 2Chosun University Hospital, Gwangju, Korea
Background: Although considerable number of amnestic mild cognitive impairment (aMCI) individuals show low beta-amyloid protein (Aβ) deposition (aMCI_Aβ-), little is known about the neural basis for cognitive deficits, particularly executive deficits. Therefore, this study aimed to identify the functional neural correlates of executive deficits in aMCI_ Aβ-, and compared to aMCI with high Aβ burden (aMCI_Aβ+). Methods: Data were selected from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database. Based on mean florbetapir standard uptake value ratio (SUVR), aMCI group was divided into aMCI_Aβ- (n=230) and aMCI_Aβ+ (n=268). Downloaded FDG-PET images were preprocessed and analyzed using statistical parametric mapping 8. Correlation between the ADNI composite scores for executive function (ADNI-EXE) and regional cerebral glucose metabolism (rCMglc) were analyzed using multiple regression model with age, gender, and education as covariates. Statistical threshold was p < 0.001, uncorrected for multiple comparison. Results: For aMCI_Aβ-, significant positive correlations between ADNI_EXE and rCMglc were found only in the bilateral cingulate cortex. For aMCI_Aβ+, significant positive correlations between ADNI_EXE and rCMglc were found in the bilateral parietal, temporal, and frontal regions. These patterns of correlation were remained unchanged when clinical severity was added as covariate. Conclusions: Our findings indicate that executive deficit in aMCI depends on different functional brain regions according to Aβ burden level. Executive deficit in aMCI_Aβ- is associated with cingulate gyrus, whereas executive deficit in aMCI_Aβ+ is associated with typical AD signature regions.
Topic Area: EXECUTIVE PROCESSES: Development & aging