title: Global association between cortical thinning and white matter integrity reduction in schizophrenia.
abstract: Previous neuroimaging studies have revealed that both gray matter (GM) and white matter (WM) are altered in several morphological aspects in schizophrenia patients. Although several studies reported associations between GM and WM alterations in restricted regions, the existence of a global association between GM and WM pathologies is unknown. Considering the wide distribution of GM morphological changes and the profound genetic background of WM abnormalities, it would be natural to postulate a global association between pathologies of GM and WM in schizophrenia. In this investigation, we studied 35 schizophrenia patients and 35 healthy control subjects using T1-weighted magnetic resonance imaging and diffusion tensor imaging (DTI) and investigated the association between GM thickness and WM fractional anisotropy (FA) as a proxy of pathology in each tissue. To investigate cortical thickness, surface-based analysis was used. The mean cortical thickness for the whole brain was computed for each hemisphere, and group comparisons were performed. For DTI data, mean FA for the whole brain was calculated, and group comparisons were performed. Subsequently, the correlation between mean cortical thickness and mean FA was investigated. Results showed that the mean cortical thickness was significantly thinner, and the mean FA was significantly lower in schizophrenia patients. Only in the patient group the mean cortical thickness and mean FA showed significant positive correlations in both hemispheres. This correlation remained significant even after controlling for demographic and clinical variables. Thus, our results indicate that the GM and WM pathologies of schizophrenia are intertwined at the global level.
authors: *To whom correspondence should be addressed; 54 Shogoin-Kawahara-cho, Kyoto 606-8507, Japan; tel: +81 75 751 3386, fax: +81 75 751 3246, e-mail: miyata10@kuhp.kyoto-u.ac.jp.
authors: Akihiko
authors: A
authors: Sasamoto
authors: Jun
authors: J
authors: Miyata
authors: Manabu
authors: M
authors: Kubota
authors: Kazuyuki
authors: K
authors: Hirao
authors: Ryosaku
authors: R
authors: Kawada
authors: Shinsuke
authors: S
authors: Fujimoto
authors: Yusuke
authors: Y
authors: Tanaka
authors: Masaaki
authors: M
authors: Hazama
authors: Genichi
authors: G
authors: Sugihara
authors: Nobukatsu
authors: N
authors: Sawamoto
authors: Hidenao
authors: H
authors: Fukuyama
authors: Hidehiko
authors: H
authors: Takahashi
authors: Toshiya
authors: T
authors: Murai
mesh_terms: D000328:Adult; D016880:Anisotropy; D001921:Brain / Q000473:pathology*; D002540:Cerebral Cortex / Q000473:pathology; D056324:Diffusion Tensor Imaging / Q000295:instrumentation / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D012559:Schizophrenia / Q000473:pathology*
keywords: cortical thickness; diffusion tensor imaging; schizophrenia; surface-based approach; white matter integrity