Structural and functional brain abnormalities in drug-naive, first-episode, and chronic patients with schizophrenia: a multimodal MRI study

Abstract

BackgroundStructural and functional brain abnormalities in schizophrenia (SZ) have been widely reported. However, a few studies have investigated both structural and functional characteristics in SZ patients at different stages to understand the neuropathology of SZ.MethodsIn this study, we recruited 44 first-episode drug-naive SZ (FESZ) patients, 44 medicated chronic SZ (CSZ) patients, and 56 normal controls (NCs) and acquired their structural and resting-state functional magnetic resonance imaging (MRI). We then made group comparisons on structural and functional characteristics, including regional gray matter volume (GMV), regional homogeneity, amplitude of low-frequency fluctuation, and degree centrality. A linear support vector machine (SVM) combined with a recursive feature elimination (RFE) algorithm was implemented to discriminate three groups.ResultsOur results indicated that the regional GMV was significantly decreased in patients compared with that in NCs; CSZ patients have more diffused GMV decreases primarily involved in the frontal and temporal lobes when compared with FESZ patients. Both FESZ and CSZ patients showed significant functional alterations compared with NCs; when compared with FESZ patients, CSZ patients showed significant reductions in functional characteristics in several brain regions associated with auditory, visual processing, and sensorimotor functions. Moreover, a linear SVM combined with a RFE algorithm was implemented to discriminate three groups. The accuracies of the three classifiers were 79.80%, 83.16%, and 81.71%, respectively. The performance of classifiers in this study with multimodal MRI was better than that of previous discriminative analyses of SZ patients with single-modal MRI.ConclusionOur findings bring new insights into the understanding of the neuropathology of SZ and contribute to stage-specific biomarkers in diagnosis and interventions of SZ.

Conceptual disorganization and redistribution of resting-state cortical hubs in untreated first-episode psychosis: A 7T study

“…The observed reduction in centrality across core hubs with a smaller magnitude of increase in centrality in other regions is also consistent with many prior observations of reduced degree centrality 29 – 31 , though Tang et al 32 reported no centrality reductions in schizophrenia. Tang and colleagues studied a relatively younger age group of subjects with >50% medicated for an unspecified amount of time; and considered only positive values of functional connectivity to quantify centrality.…”

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

“…It is remarkable that a single brain map (the 2back map) allowed for a high accuracy between patients and controls, and this is quite likely to be behind the best accuracies reached by the two-step Ridge classifier (87%). This figure is higher than the accuracies reported in recent multimodal classification studies in schizophrenia such as the 83% of Wu et al (2018) and substantially higher than the 75% of Cabral et al (2016). However, these studies did not include task-based fMRI data as in ours.…”

Brain function, structure and genomic data are linked but show different sensitivity to duration of illness and disease stage in schizophrenia

“…We have noticed that there were some literatures in schizophrenia stating that notable GM and FC deficits were revealed in the early stage of the disease. However, in current work, we only observed moderately decreased GM in FESZ, due to the following potential reasons.1) The first-episode patients collected in current study have a relatively short duration of illness (≤ 2 years), less than those FESZ reported with DOI≤5 years, and previous studies (Jiang et al, 2018; Klauser et al, 2015; Wu et al, 2018) also reported un-significant GMV reduction in the high-risking patients and progressive GMV reductions in schizophrenia patients, supporting our findings. 2) Earlier age of onset of schizophrenia has been reported to be associated with larger regional GM deficits(Torres et al, 2016) and worse outcome(Clemmensen et al, 2012).…”