Cerebellar structural abnormalities associated with cognitive function in patients with first-episode psychosis

Abstract

The fundamental role of the cerebellum in higher cognitive processing has been highlighted in schizophrenia in recent years. However, inconsistent findings exist with respect to the cerebellar substructure volume in schizophrenia, and little is known regarding the association between cerebellar structural abnormalities, and cognitive and clinical dysfunctions in patients. This study aimed to measure the cerebellar structural volume and investigate its association with neuropsychological tests and clinical scores at the early stage of schizophrenia.

Cerebellar volume was measured in 40 patients with first-episode psychosis (FEP) and 40 healthy controls using two complementary approaches: whole-brain voxel-based morphometry (VBM) and automated cerebellar lobule segmentation based on a graph-cut algorithm. A battery of neuropsychological tests and clinical scales were used to investigate the correlation with cerebellar regional volumes.

Both the VBM and automated segmentation analyses indicated a reduced gray matter volume in the superior posterior lobe (Crus I/II in VBM

right VIIb in automated segmentation) in FEP patients. Furthermore, compared with the healthy controls, the FEP patients showed significantly reduced volumes in the right VIIb, the corpus medullare, and the VI vermis, as well as a trend toward reduction in the total vermis volume with the lobular analysis. The volume reduction in the superior posterior lobe was correlated with a worse performance on working memory and immediate recall. The loss of the corpus medullare volume was correlated with higher PANSS positive scores and lower GAF scores.

Regional structural alterations in the superior posterior lobe and the corpus medullare were identified in FEP patients, and cerebellar volume reductions were associated with working memory, immediate recall, PANSS and GAF scores. Our findings support the involvement of the cerebellar substructure in patients and suggest that the gray matter differences in the superior posterior and corpus medullare are associated with the functioning of FEP patients.