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IC‐P2‐157: fMRI activation in medial temporal lobe correlates with monthly decline rate of memory function in mild cognitive impairment patients
Author(s) -
Xu Guofan,
Dowling Maritza,
Kastman Erik K.,
Fitzgerald Michele E.,
Sager Mark A.,
Asthana Sanjay,
Johnson Sterling C.
Publication year - 2008
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.2008.05.2611
Subject(s) - audiology , cognitive decline , temporal lobe , cognition , neuropsychology , psychology , episodic memory , neuropsychological test , verbal learning , medicine , neuroscience , dementia , disease , epilepsy
Background: This study is aimed to assess the relationship between BOLD fMRI memory task activation and cognition decline rate in nondemented older adults as well as in mild cognitive impairment amnestic (MCI) patients who are at greater risk for developing Alzheimer disease (AD). Methods: Twenty-nine cognitively normal middleage controls (55-60y), 14 MCI patients (65-75y) and 9 cognitively normal elder controls (65-75y) participated this longitudinal study. All subjects had their first neuropsychological assessment with a full set of cognitive battery test when they also performed a memory-encoding fMRI scan. The MCI and elderly control subjects had a two-year follow-up while the middle-aged controls had a 4-year follow-up. The same set of cognitive battery test was given during the follow-up visit. The monthly decline rates of Rey Auditory Verbal Learning Test (RAVLT) score were calculated for each subject after adjusting for their first-visit age, gender, year of education. A voxel-based multiple linear regression model was used to exam the relationship between first-time visit fMRI activation and decline rate of RAVLT scores. Results: During their first visit, the MCI patients exhibited less activity in the right hippocampus during encoding of novel items, despite comparable task performance to the controls. The monthly decline rate of RAVLT trial7 score was found significantly correlated with the right insular cortex BOLD activation signal during the first-visit. Such a correlation is not significant among the elderly and middle-age controls. Conclusions: Reduced fMRI signal change in the MTL supports prior studies implicating the hippocampus for encoding new information. The close correlation between MTL BOLD signal and the longitudinal cognitive decline rate in MCI subjects suggests the predicative value of fMRI signal in AD.