Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Semantic memory activation in individuals at risk for developing Alzheimer disease.

Authors
Seidenberg-M; Guidotti-L; Nielson-KA; Woodard-JL; Durgerian-S; Antuono-P; Zhang-Q; Rao-SM
Source
Neurology 2009 Aug; 73(8):612-620
NIOSHTIC No.
20035817
Abstract
OBJECTIVE: To determine whether whole-brain, event-related fMRI can distinguish healthy older adults with known Alzheimer disease (AD) risk factors (family history, APOE epsilon4) from controls using a semantic memory task involving discrimination of famous from unfamiliar names. METHODS: Sixty-nine cognitively asymptomatic adults were divided into 3 groups (n = 23 each) based on AD risk: 1) no family history, no epsilon4 allele (control [CON]); 2) family history, no epsilon4 allele (FH); and 3) family history and epsilon4 allele (FH+epsilon4). Separate hemodynamic response functions were extracted for famous and unfamiliar names using deconvolution analysis (correct trials only). RESULTS: Cognitively intact older adults with AD risk factors (FH and FH+epsilon4) exhibited greater activation in recognizing famous relative to unfamiliar names than a group without risk factors (CON), especially in the bilateral posterior cingulate/precuneus, bilateral temporoparietal junction, and bilateral prefrontal cortex. The increased activation was more apparent in the FH+epsilon4 than in the FH group. Unlike the 2 at-risk groups, the control group demonstrated greater activation for unfamiliar than familiar names, predominately in the supplementary motor area, bilateral precentral, left inferior frontal, right insula, precuneus, and angular gyrus. These results could not be attributed to differences in demographic variables, cerebral atrophy, episodic memory performance, global cognitive functioning, activities of daily living, or depression. CONCLUSIONS: Results demonstrate that a low-effort, high-accuracy semantic memory activation task is sensitive to Alzheimer disease risk factors in a dose-related manner. This increased activation in at-risk individuals may reflect a compensatory brain response to support task performance in otherwise asymptomatic older adults.
Keywords
Age-groups; Brain-disorders; Brain-function; Central-nervous-system; Cerebrovascular-system; Dose-response; Exposure-assessment; Exposure-levels; Exposure-methods; Mental-disorders; Mental-health; Mental-processes; Risk-analysis; Risk-factors
Contact
Dr. Stephen M. Rao, Schey Center for Cognitive Neuroimaging, Neurological Institute, Cleveland Clinic, 9500 Euclid Ave./U10, Cleveland, OH 44195
CODEN
NEURAI
Publication Date
20090825
Document Type
Journal Article
Email Address
raos2@ccf.org
Funding Type
Grant
Fiscal Year
2009
NTIS Accession No.
NTIS Price
Identifying No.
Grant-Number-T42-OH-008672
Issue of Publication
8
ISSN
0028-3878
Source Name
Neurology
State
IL; OH
Performing Organization
University of Illinois at Chicago
TOP