Non redundant functional brain connectivity in schizophrenia

Abstract

Schizophrenia is considered a disorder of abnormal brain connectivity. Although whole brain maps of averaged bivariate voxel correlations have been successfully applied to study connectivity abnormalities in schizophrenia these maps do not adequately explore the multivariate nature of brain connectivity. Here we adapt a novel method for highdimensional regression (supervised principal component regression) to estimate brain maps of multivariate non redundant connectivity (NRC) from resting functional Magnetic Resonance Imaging (fMRI) data of 116 patients with schizophrenia and 122 matched controls. Disorder related differences in NRC involved caudate hyper-connectivity and hypo-connectivity of several cortical areas such as the dorsal cingulate, the cuneus and the right postcentral cortex. These abnormalities were coupled with abnormalities in the amplitude of signal fluctuations and, to a minor extent, with differences in the dimensionality of connectivity patterns as quantified by the number of supervised principal components. Second level seed correlation analyses linked the observed abnormalities to an additional set of brain regions relevant to schizophrenia such as the thalamus and the temporal cortex. The non redundant connectivity maps proposed here are a new tool that will complement the information provided by other already available voxel based whole brain connectivity measures.

Amplitude of low-frequency fluctuation (ALFF) may be associated with cognitive impairment in schizophrenia: a correlation study

“…A meta-analysis [27] also reported increased ALFF in the medial superior frontal gyri, which is consistent with our study. Furthermore, previous studies have reported decreased ALFF in the bilateral lingual [28], calcarine, cuneus, and postcentral gyri [44] areas of the brains of SZ patients (Table 3).…”

Abnormalities of intrinsic regional brain activity in first-episode and chronic schizophrenia: a meta-analysis of resting-state functional MRI

“…67,68 In the end, 24 studies reporting 28 data sets that investigated ALFF differences between patients with schizophrenia and healthy controls were eligible for inclusion. [14][15][16][17][18]21,23,[25][26][27][28][69][70][71][72][73][74][75][76][77][78][79][80] Of these, 11 (13 data sets) were first-episode samples 14,15,18,21,23,25,26,69,71,76,81 and 13 (15 data sets) were chronic samples. 16,17,27,28,70,[72][73][74][75][77][78][79][80] Of the first-episode samples, 69% were medication-naïve; the results for medication-naïve patients with first-episode sc...…”

Multimodal Integration of Brain Images for MRI-Based Diagnosis in Schizophrenia

“…MRI acquisitions included a T1 structural image, a resting-state fMRI sequence, and an fMRI acquisition obtained during performance of the n back task (a working memory task). Acquisition parameters as well as a detailed description of the preprocessing steps applied to the images can be found in previous reports: T1 (Salvador et al, 2017b), resting-state fMRI (Salvador et al, 2017a), and the n -back task (Fuentes-Claramonte et al, 2019). Images from all modalities were coregistered to the same standard MNI152 T1 2 mm template.…”