Understanding structural brain changes in schizophrenia

Abstract

Schizophrenia is a chronic progressive disorder that has at its origin structural brain changes in both white and gray matter. It is likely that these changes begin prior to the onset of clinical symptoms in cortical regions, particularly those concerned with language processing. Later, they can be detected by progressive ventricular enlargement. Current magnetic resonance imaging (MRI) technology can provide a valuable tool for detecting early changes in cortical atrophy and anomalous language processing, which may be predictive of who will develop schizophrenia.

Figure 1.. Magnetic resonance imaging (MRI) of a female patient who initially was scanned at the time of hospitalization for a first episode of schizophrenia. At the tenth year of follow-up, at age 34, she was an outpatient with a diagnosis of chronic schizophrenia stabilized with predominantly negative symptoms. She also had a brother with chronic schizophrenia, but he did not participate in the longitudinal study.

Figure 2.. Diffusion tensor imaging (DTI). Fractional anisotropy (FA) of 15 subjects at high genetic risk for schizophrenia. Sagittal view showing FA reduced in the left posterior superior temporal gyrus in high-risk subjects compared with controls (P<0.01 , minimum cluster size =100). Talairach coordinates of cluster peaks: x=-41 , y=-36, z=9.

Figure 3.. Sagittal, coronal, and axial views of the region in the vicinity of the left parahippocampal gyrus and right superior frontal gyrus, where the apparent diffusion coefficient (ADC) was higher both in (A, C) subjects at high genetic risk for schizophrenia and (B, D) the patients with schizophrenia P<0.01 , cluster size >200 mm as compared with controls. Sagittal, coronal, and axial views of the region in the left superior frontal gyrus and left middle frontal gyrus shows that subjects at high genetic risk for schizophrenia (E, G) and patients with schizophrenia (F, H) had higher ADC compared with controls: P<0.01, cluster size >200 mm in these regions as well.

Figure 4.. Magnetisation transfer (MT): Coronal (A and C) and sagittal (B) views showing a greater magnetisation transfer ratio (MTR) in controls compared with subjects at high genetic risk for schizophrenia bilaterally in the superior frontal gyrus (P<0.05, minimum cluster size =100). Talairach coordinates of cluster peaks: A and B, x=-10,y=14, z=52; C, x=10, y=1 5, z=51.

Figure 5.. Magnetization transfer (MT). Greater magnetization transfer ratio (MTR) is shown in controls versus subjects at high genetic risk for schizophrenia in the posterior cingulate gyrus (P<0.05, minimum cluster size =100). Talairach coordinates of cluster peaks: A, x=-0, y=-36, z=27; B, x=8, y=-45, z=22.

Figure 6.. Functional magnetic resonance imaging (fMRI) showing brain activation during a lexical decision task (no REST contrast) in 11 controls (A), 9 subjects at high risk for schizophrenia (B), and 11 patients with chronic schizophrenia (C). Lateralization of activation is reduced in the schizophrenic patients compared to controls (P<0.01) as well as the subjects at high risk, but to a lesser extent (P<0.01).