Abnormal white matter microstructure in schizophrenia: a voxelwise analysis of axial and radial diffusivity.

Diffusion Tensor Imaging (DTI) investigations in schizophrenia have provided evidence of impairment in white matter as indicated by reduced fractional anisotropy (FA). However, the neuropathological implications of these findings remain unclear. In the current study, we conducted a voxelwise analysis of the constituent parameters of FA, Axial (lambda(||)) and Radial Diffusivity (lambda( upper left and right quadrants)), in 14 male participants with schizophrenia and 14 age, gender, education, and premorbid intelligence matched healthy controls. Significantly reduced FA and higher Radial Diffusivity were concurrently observed in several major white matter tracts in the schizophrenia group. This finding suggests that the loss of white matter integrity in schizophrenia is the result of demyelination and/or changes to the axonal cytoskeleton rather than gross axonal damage.