Investigating connectivity between the cerebellum and thalamus in schizophrenia using diffusion tensor tractography: a pilot study

Abstract

Connections of the cortical-thalamic-cerebellar-cortical regions provide a framework for studying the neural substrates of schizophrenia. A novel diffusion tensor tractography method was used to evaluate the differences in white matter connectivity between 12 patients with schizophrenia and 10 controls. For the tract tracing, we focused on the connection between the cerebellum and the thalamus. Fractional anisotropy (FA) measures along the fiber tracks were compared between patients and the control sample. Fiber tracts located between the cerebellar white matter and the thalamus exhibit a reduced FA in patients with schizophrenia in comparison with controls. The FA values along the defined fiber tracts were not overall reduced but exhibited a reduction in the anisotropy in the region in the superior cerebellar peduncles projecting towards the red nucleus.

Fig. 1

FA values along the tracts connecting the cerebellum and thalamus. The graphs show the fractional anisotropy (FA) with the error bars representing the standard deviation. The P-values at each of the tract locations are displayed in green with the significance level of P<0.05 marked as a solid line. The fiber tracts from the left cerebellum to right thalamus are shown in a and b while the right cerebellum to left thalamus are shown in c and d. The black box defines locations along the fiber tract that fall below P<0.05.

Fig. 2

The top row shows the fiber tracts between the left cerebellum and right thalamus for one of the subjects shown in axial and coronal orientations. The bottom row shows the fiber tracts between the right cerebellum and left thalamus. The fiber tracts are color-coded, showing the area of significant reduction in the FA values in patients with schizophrenia in blue and the remaining areas in red.