Semantic Memory Activation in Individuals at Risk for Developing Alzheimer Disease

Details

• Personal Author:
  Antuono P ; Durgerian S ; Guidotti L ; Nielson KA ; Rao SM ; Seidenberg M ; Woodard JL ; Zhang Q
• Description:
  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. [Description provided by NIOSH]
• Subjects:
  Aging Cardiovascular System Environmental Monitoring Mental Disorders Mental Health Nervous System Nervous System Diseases Occupational Health Risk Assessment Risk Factors Safety

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• 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

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• ISSN:
  0028-3878
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Illinois ; Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  73
• Issue:
  8
• NIOSHTIC Number:
  nn:20035817
• Citation:
  Neurology 2009 Aug; 73(8):612-620
• Contact Point Address:
  Dr. Stephen M. Rao, Schey Center for Cognitive Neuroimaging, Neurological Institute, Cleveland Clinic, 9500 Euclid Ave./U10, Cleveland, OH 44195
• Email:
  raos2@ccf.org
• Federal Fiscal Year:
  2009
• Performing Organization:
  University of Illinois at Chicago
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Neurology
• End Date:
  20290630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:04e242495667f7e8a5ec5bdbc437f6c8608169e5eeebf6e02f1d9d744f26a050384553330fbeb5368ad91b01a56d5738d7061dc4df10c0fe0616ac59e700475c
• Download URL:
  https://stacks.cdc.gov/view/cdc/187529/cdc_187529_DS1.pdf
• File Type:
  [PDF - 724.06 KB ]