Abnormal intrinsic brain activity patterns in patients with subcortical ischemic vascular dementia.
OBJECTIVE
To investigate the amplitude of low-frequency fluctuations (ALFF) alteration of whole brain in patients with subcortical ischemic vascular dementia (SIVD).


METHODS
Thirty patients with SIVD and 35 control subjects were included in this study. All of them underwent structural MRI and rs-fMRI scan. The structural data were processed using the voxel-based morphometry 8 toolbox (VBM8). The rs-fMRI data were processed using Statistical Parametric Mapping (SPM8) and Data Processing Assistant for Resting-State fMRI (DPARSF) software. Within-group analysis was performed with a one-sample Student's t-test to identify brain regions with ALFF value larger than the mean. Intergroup analysis was performed with a two-sample Student's t-test to identify ALFF differences of whole brain between SIVD and control subjects. Partial correlations between ALFF values and Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) scores were analyzed in the SIVD group across the parameters of age, gender, years of education, and GM volume.


RESULTS
Within-group analysis showed that the bilateral anterior cingulate cortex (ACC), posterior cingulate cortex, medial prefrontal cortex (MPFC), inferior parietal lobe (IPL), occipital lobe, and adjacent precuneus had significantly higher standardized ALFF values than the global mean ALFF value in both groups. Compared to the controls, patients with SIVD presented lower ALFF values in the bilateral precuneus and higher ALFF values in the bilateral ACC, left insula and hippocampus. Including GM volume as an extra covariate, the ALFF inter-group difference exhibited highly similar spatial patterns to those without GM volume correcting. Close negative correlations were found between the ALFF values of left insula and the MoCA and MMSE scores of SIVD patients.


CONCLUSIONS
SIVD is associated with a unique spontaneous aberrant activity of rs-fMRI signals, and measurement of ALFF in the precuneus, ACC, insula, and hippocampus may aid in the detection of SIVD.
Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
Chen
C
Liu
Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
Chuanming
C
Li
Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
Xuntao
X
Yin
Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
Jun
J
Yang
Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
Daiquan
D
Zhou
Department of Neurology, Southwest Hospital, Third Military Medical University, Chongqing, China.
Li
L
Gui
Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
Jian
J
Wang
D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000503:physiopathology*; D002545:Brain Ischemia / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000473:pathology*; D015140:Dementia, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged