title: Posterior cingulate cortex atrophy and regional cingulum disruption in mild cognitive impairment and Alzheimer's disease.
abstract: This study aimed to investigate the atrophy of the posterior cingulate cortex (PCC) and medical temporal lobe (MTL) structures (i.e., the entorhinal cortex (ERC) and hippocampus) and the regional disruption of the cingulum bundle in mild cognitive impairment (MCI) and Alzheimer's disease (AD) patients. The relationships between atrophy of these structures and regional cingulum disruption were also explored. Three-dimensional MRI and diffusion tensor imaging were applied to 19 MCI, 19 probable AD patients, and 18 normal controls (NC). Fractional anisotropy (FA) values were obtained from three different regions of the cingulum. Both MCI and AD patients showed decreased PCC volumes compared with NC. ERC atrophy was also significant in AD and MCI, while hippocampus atrophy was significant only in AD. MCI patients showed a significant FA decrease in the parahippocampal cingulum (PH-C), whereas AD patients had lower FA values in the posterior cingulate cingulum (PC-C) and PH-C, as compared with NC. However, the middle cingulate cingulum (MC-C) showed no significant FA differences between groups. Moreover, the volumes of MTL structures were significantly correlated with PH-C and PC-C FA values. In terms of PCC functional deficit in MCI or early AD, our results support both the direct effect of PCC atrophy itself and the indirect effect of cingulum fiber degeneration secondary to MTL atrophy.
authors.affiliation: Department of Neuropsychiatry and Clinical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Il Han
authors.initials: IH
authors.lastname: Choo
authors.forename: Dong Young
authors.initials: DY
authors.lastname: Lee
authors.forename: Jungsu S
authors.initials: JS
authors.lastname: Oh
authors.forename: Jae Sung
authors.initials: JS
authors.lastname: Lee
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
authors.forename: In Chan
authors.initials: IC
authors.lastname: Song
authors.forename: Jong Choul
authors.initials: JC
authors.lastname: Youn
authors.forename: Shin Gyeom
authors.initials: SG
authors.lastname: Kim
authors.forename: Ki Woong
authors.initials: KW
authors.lastname: Kim
authors.forename: Jin Hyeong
authors.initials: JH
authors.lastname: Jhoo
authors.forename: Jong Inn
authors.initials: JI
authors.lastname: Woo
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000473:pathology*; D000704:Analysis of Variance; D001284:Atrophy / Q000473:pathology; D002540:Cerebral Cortex / Q000473:pathology*; D016009:Chi-Square Distribution; D003072:Cognition Disorders / Q000473:pathology*; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D018579:Patient Selection