A review of diffusion tensor imaging studies in schizophrenia

Abstract

Both post-mortem and neuroimaging studies have contributed significantly to what we know about the brain and schizophrenia. MRI studies of volumetric reduction in several brain regions in schizophrenia have confirmed early speculations that the brain is disordered in schizophrenia. There is also a growing body of evidence suggesting that a disturbance in connectivity between different brain regions, rather than abnormalities within the separate regions themselves, are responsible for the clinical symptoms and cognitive dysfunctions observed in this disorder. Thus an interest in white matter fiber tracts, subserving anatomical connections between distant, as well as proximal, brain regions, is emerging. This interest coincides with the recent advent of diffusion tensor imaging (DTI), which makes it possible to evaluate the organization and coherence of white matter fiber tracts. This is an important advance as conventional MRI techniques are insensitive to fiber tract direction and organization, and have not consistently demonstrated white matter abnormalities. DTI may, therefore, provide important new information about neural circuitry, and it is increasingly being used in neuroimaging studies of psychopathological disorders. Of note, in the past five years 18 DTI studies in schizophrenia have been published, most describing white matter abnormalities. Questions still remain, however, regarding what we are measuring that is abnormal in this disease, and how measures obtained using one method correspond to those obtained using other methods? Below we review the basic principles involved in MR-DTI, followed by a review of the different methods used to evaluate diffusion. Finally, we review MR-DTI findings in schizophrenia.

Deviant trajectories of cortical maturation in 22q11.2 deletion syndrome (22q11DS): A cross-sectional and longitudinal study

“…However, the association between aberrant pruning and schizophrenic symptomatology remains difficult to prove in vivo, e.g. using EEG (Micheloyannis et al, 2006), fMRI (Liu et al, 2008), or DTI (Kubicki et al, 2007). In this study, we observed that adult patients with 22q11DS and without schizophrenia demonstrate preserved thickness as compared to age-matched controls.…”

Age-related deficits in fronto-temporal connections in schizophrenia: A diffusion tensor imaging study

“…However, with newer, faster MR systems, where it is not too costly to use higher directional resolution, one should certainly consider doing so. Additionally, we note that tractography stopping criteria of 20° of curvature change within 1 mm, are quite common in the literature, and have been introduced in order to deal with potential artifacts in the data that could influence the tractography output (see review in Kubicki et al, 2007).…”

Molecular dissection of NRG1-ERBB4 signaling implicates PTPRZ1 as a potential schizophrenia susceptibility gene

“…[76][77][78][79] These oligodendrocyte abnormalities may in turn contribute to the loss of coherence of axon tracts, and reduced connectivity, in schizophrenia. 80,81 Alterations in NRG1-ERBB4 and/or PTPRZ1 signaling may cause these oligodendrocyte abnormalities, in addition to potential neuronal effects.…”