Fiber geometry in the corpus callosum in schizophrenia: Evidence for transcallosal misconnection

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• 作者：Thomas J. Whitford^a ; ^b ; ¹ ; ^{whitford@bwh.harvard.edu} ; Peter Savadjiev^a ; ^d ; ¹ ; Marek Kubicki^a ; ^c ; Lauren J. O'Donnell^d ; ^e ; Douglas P. Terry^a ; Sylvain Bouix^a ; ^c ; Carl-Fredrik Westin^d ; Jason S. Schneiderman^a ; Laurel Bobrow^a ; Andrew C. Rausch^a ; Margaret Niznikiewicz^c ; Paul G. Nestor^c ; ^f ; Christos Pantelis^b ; Stephen J. Wood^b ; ^g ; Robert W. McCarley^c ; Martha E. Shenton^a ; ^c
• 关键词：Callosal ; Diffusion-Tensor Imaging ; Neurodevelopment ; Morphometry ; White-matter ; Genu
• 刊名：Schizophrenia Research
• 出版年：2011
• 出版时间：October, 2011
• 年：2011
• 卷：132
• 期：1
• 页码：69-74
• 全文大小：1K

文摘

Background

Structural abnormalities in the callosal fibers connecting the heteromodal association areas of the prefrontal and temporoparietal cortices bilaterally have been suggested to play a role in the etiology of schizophrenia.

Aims

To investigate for geometric abnormalities in these callosal fibers in schizophrenia patients by using a novel Diffusion-Tensor Imaging (DTI) metric of fiber geometry named Shape-Normalized Dispersion (SHD).

Methods

DTIs (3T, 51 gradient directions, 1.7 mm isotropic voxels) were acquired from 26 schizophrenia patients and 23 matched healthy controls. The prefrontal and temporoparietal fibers of the corpus callosum were extracted by means of whole-brain tractography, and their mean SHD calculated.

Results

The schizophrenia patients exhibited subnormal levels of SHD in the prefrontal callosal fibers when controlling for between-group differences in Fractional Anisotropy. Reduced SHD could reflect either irregularly turbulent or inhomogeneously distributed fiber trajectories in the corpus callosum.

Conclusions

The results suggest that the transcallosal misconnectivity thought to be associated with schizophrenia could reflect abnormalities in fiber geometry. These abnormalities in fiber geometry could potentially be underpinned by neurodevelopmental irregularities.