Diffusion Tensor Imaging Findings of White Matter Changes in First Episode Schizophrenia: A Systematic Review

Abstract

Earlier structural magnetic resonance imaging in schizophrenia have noted smaller white matter volumes in diverse brain regions and recent diffusion tensor imaging (DTI) studies have allowed better elucidation of changes in brain white matter integrity within the illness. As white matter abnormalities have been reported to occur early in the course of schizophrenia, we systematically review extant DTI studies of anomalies of white matter integrity in first episode schizophrenia (FES) up till October 2011. Overall, disruptions of white matter integrity were found in the cortical, subcortical brain regions and white matter associative and commissural tracts, suggesting that changes of cortical-subcortical white matter integrity were found at an early stage of the disorder. These changes in white matter integrity were correlated with specific cognitive deficits (verbal and spatial working memory) as well as psychopathology (positive more than negative symptoms) in patients with FES. The correlation of these white matter integrity changes with cognitive and phenomenological factors may shed light on neurobiological substrates underlying these clinical manifestations. Future studies need to validate these findings in larger samples of subjects and in different populations as well as chart the progress of these cerebral white matter changes over time so as to better appreciate their trajectory with illness course, treatment and chronicity.

Myelin, myelin-related disorders, and psychosis

“…DTI studies on first episode schizophrenia (FES) patients have shown compromised white matter integrity in cortical and subcortical brain regions, and white matter association and commissural tracts. These investigations support the notion that white matter pathology is present from the earliest stages of illness (Kuswanto et al, 2012). However, DTI abnormalities in first episode patients are less robust than in chronic patients, indicating that other factors may contribute to a progressive loss of white matter following the onset of illness (Peters et al, 2010).…”

Neuroimaging Biomarkers for Psychosis

“…The second region, in the temporal lobe, is traversed by white matter tracts interconnecting the frontal lobe, insula, hippocampus–amygdala, temporal and occipital lobe”. A recent meta-analysis on FES [37] showed that “disruptions of white matter integrity were found in the cortical, subcortical brain regions and white matter associative and commissural tracts, suggesting that changes of cortical-subcortical white matter integrity were found at an early stage of the disorder”.…”

Diffusion tensor imaging study of the fornix in first episode schizophrenia and in healthy controls

“…There are more inconsistencies, however, among studies of first episode schizophrenia (FE, see for example reviews in Kuswanto et al, 2012; Samartzis et al, 2013). In the current study, we focus on the fornix, a compact bundle of white matter fibers that projects from the hippocampus to the mamillary bodies, and is part of the limbic system.…”