Stochastic Tractography Study of Inferior Frontal Gyrus Anatomical Connectivity in Schizophrenia

M. Kubicki, J. Alvarado, C.F. Westin, D. Tate, D. Markant, D. Terry, T. Whitford, J. Siebenthal, S. Bouix, R. McCarley, R. Kikinis, M. E. Shenton
NeuroImage
Volume 55, Pages 1657-1664
2011

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Abstract

Background: Abnormalities within language-related anatomical structures have been associated with clinical symptoms and with language and memory deficits in schizophrenia. Recent studies suggest disruptions in functional connectivity within the Inferior Frontal Gyrus (IFG) network in schizophrenia. However, due to technical challenges, anatomical connectivity abnormalities within this network and their involvement in clinical and cognitive deficits have not been studied.

Material and methods: Diffusion and anatomical scans were obtained from 23 chronic schizophrenia patients and 23 matched controls. The IFG was automatically segmented, and its white matter connections extracted and measured with newly-developed stochastic tractography tools. Correlations between anatomical structures and measures of semantic processing were also performed.

Results: White Matter connections between the IFG and posterior brain regions followed two distinct pathways: dorsal and ventral. Both demonstrated left lateralization, but ventral pathway abnormalities were only found in schizophrenia. IFG volumes also showed left lateralization and abnormalities in schizophrenia. Further, despite similar laterality and abnormality patterns, IFG volumes and white matter connectivity were notcorrelatedwitheachotherineithergroup.Interestingly,measures ofsemanticprocessingcorrelatedwith white matter connectivity in schizophrenia and with gray matter volumes in controls. Finally, hallucinations were best predicted by both gray matter and white matter measures together.

Conclusions: Our results suggest abnormalities within the ventral IFG network in schizophrenia, with white matter abnormalities better predicting semantic deficits. The lack of a statistical relationship between coexisting gray and white matter deficits might suggest their different origin and the necessity for a multimodal approach in future schizophrenia studies.


Reference

Kubicki M, Alvarado J, Westin C, Tate D, Markant D, Terry D, Whitford T, Siebenthal J, Bouix S, McCarley R, Kikinis R, Shenton ME. Stochastic tractography study of inferior frontal gyrus anatomical connectivity in schizophrenia. NeuroImage 2011;55:1657-1664.

Grants

K05 MH070047, K23-MH073416, P30-AG013846, P41 RR013218, P50MH 080272, R01 MH 082918, R01 MH 40799, R01 MH 50740, R01 MH050740-15, R01 MH074794-05, R01 MH082918-03, R01MH 074794, U54 EB005149 U54 EB005149-07

Research area

dti
© 2013 Psychiatry Neuroimaging Laboratory | Last updated 04.15.2013