P4‐104: Alzheimer's disease reduces inter‐hemispheric hippocampal functional connectivity

• DOI: 10.1016/j.jalz.2011.05.2125
• Publication Date: 2011-08-02T02:19:55Z
• Authors: Igor Korolev; Andrea Bozoki; Shantanu Majumdar; Kevin Berger; David Zhu
• Keywords: Blood-oxygen-level dependent

Alzheimer's disease (AD) causes pronounced hippocampalatrophy, as measured by structural magnetic resonance imaging (sMRI). Studies using resting-state functional MRI (rs-fMRI) have also revealed that AD disrupts connectivity within the brain's default-mode network, which: -36px; font: normal 12px/normal arial; '' > hypometabolism during early stages of AD). However, current understanding regarding effects on hippocampus is limited. The goal present study was to examine whether alters between right and left hippocampi (fcHPC). Nineteen subjects (aged 73 ± 7 years old) participated in this study, including 10 patients with mild-to-moderate 9 age-matched control (NC) subjects. All underwent sMRI rs-fMRI scans at 3 Tesla completed a neuropsychological assessment. We used FreeSurfer define regions interest (ROI) from each subject's scan. Hippocampal ROIs were then eroded minimize partial volume surrounding cerebrospinal fluid. extracted spontaneous blood-oxygen-level-dependent (BOLD) signal hippocampal ROI. fcHPC determined correlating BOLD signals computing correlation coefficient (r). (12.2 6.5) attained lower scores than NC (27.1 1.2) Saint Louis University Mental Status Examination (SLUMS) [p < 0.001], reflecting their decreased cognitive function. Furthermore, (r = 0.72 0.14) showed significant reduction compared 0.83 0.07) 0.04]. To confirm finding, we correlated performance SLUMS. found direct relationship SLUMS score 0.47, p 0.05). reduces inter-hemispheric connectivity, effect parallels degree dysfunction.