Abnormal Intrinsic Brain Activity Patterns in Patients with Subcortical Ischemic Vascular Dementia

Chen Liu,Jun Yang,Li Gui,Xuntao Yin,Chuanming Li1,Jian Wang,Daiquan Zhou,Karl Herholz

doi:10.1371/journal.pone.0087880

Abstract

ObjectivesTo investigate the amplitude of low-frequency fluctuations (ALFF) alteration of whole brain in patients with subcortical ischemic vascular dementia (SIVD).Materials and MethodsThirty 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.ResultsWithin-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.ConclusionSIVD 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.

Highlights

Dementia is a syndrome with numerous symptoms, including loss of memory, judgment, reasoning, and changes in mood, behavior, and communication [1]
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 amplitude of low frequency fluctuations (ALFF) values than the global mean ALFF value in both groups
Close negative correlations were found between the ALFF values of left insula and the Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) scores of Subcortical ischemic vascular dementia (SIVD) patients

Summary

Introduction

Dementia is a syndrome with numerous symptoms, including loss of memory, judgment, reasoning, and changes in mood, behavior, and communication [1]. Subcortical ischemic vascular dementia (SIVD) is a relatively homogeneous subtype of VaD in terms of lesion location and clinical manifestations and is characterized by the presence of lacunar infarcts and white matter lesions, which are both mediated by small vessel disease [4]. The recent development of resting-state functional MRI (rsfMRI) has allowed researchers to detect intrinsic brain activity during rest and has provided valuable insights into the pathomechanism of dementia [5], currently it can’t exclude the vascular effects which may contribute to the rs-fMRI signal.

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