The study by Murakami et al. (2011) was to determine differences in cortical thickness, gray matter volume, and white matter integrity between normal subjects and schizophrenic patients. Gray and white matters were evaluated simultaneously for hypothesized disruption of neural circuits in schizophrenic mechanism with both gray and white matter involved.
The research sample includes 21 schizophrenic patients (15 males and 6 females, mean age 32.65) and 21 healthy comparisons with matched ages and genders. Psychiatric symptoms were evaluated using the Positive and Negative Syndrome Scale within 3 days prior to MR scanning. A MRI brain scanner (Signa HDx) was used to acquire T1-weighted images. Cortical thickness and gray matter volume were estimated using FreeSurfer software. White matter was calculated using TBSS software. General linear models were used for analyzing cortical thickness at each vertex. Statistical analyses include ANCOVA for gray matter volume and two t tests for white matter volume.
Research found no significant differences in cortical thickness evaluated for both hemispheres using general linear models at each vertex between schizophrenia and healthy controls. Gray matter volume measurements of hippocampus, amygdala, caudate, pallidum, putamen, and thalamus proper showed that hippocampal volume was significantly smaller in the schizophrenia group (9.75±0.94 mL) than in the healthy control group (10.32±0.77 mL). Voxel-wise analysis for white matter revealed no significant differences in FA, AD, or RD regions between schizophrenia and healthy controls. Stepwise multivariate analysis (independent variables: sex, age, duration; dependent variable: hippocampal volume) revealed positive relationship between hippocampal volume and duration of illness.
Scientists at University of Tokyo assessed gray and white matter changes in schizophrenia patients using combined analyses of cortical thickness, gray matter volume, and white matter diffusivity and anisotropy. They concluded that hippocampal volume decreases in schizophrenic patients and the loss of white matter occurs in early course of schizophrenia.
Murakami, M., Takao, H., Abe, O., Yamasue, H., Sasaki, H., Gonoi, W., & ... Ohtomo, K. (2011). Cortical thickness, gray matter volume, and white matter anisotropy and diffusivity in schizophrenia. Neuroradiology, 53(11), 859-866. doi:10.1007/s00234-010-0830-2