Reduced white matter integrity and cognitive deficit in never-medicated chronic schizophrenia: a diffusion tensor...

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Disrupted white matter (WM) integrity is a key feature in schizophrenia.
• Cognitive deficits are known to be associated with WM changes in treated patients.
• The relationship between cognition and WM abnormalities in never-medicated schizophrenia is not well understood.

Purpose of the Study:

• To investigate whole-brain white matter differences in never-medicated chronic schizophrenia patients compared to healthy controls.
• To explore the association between white matter integrity and cognitive function, as well as clinical characteristics.

Main Methods:

• Diffusion Tensor Imaging (DTI) with Tract-Based Spatial Statistics (TBSS) was used.
• Compared fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) between 17 patients and 17 controls.
• Cognitive function was assessed using the MATRICS Consensus Cognitive Battery (MCCB).

Main Results:

• Schizophrenia patients exhibited significantly reduced FA in the left inferior longitudinal fasciculus (ILF) and left inferior fronto-occipital fasciculus (IFOF).
• No differences in MD, AD, or RD were found between groups.
• Lower FA in the left ILF and IFOF correlated with poorer processing speed, verbal learning, and visual learning in patients.

Conclusions:

• WM pathway disconnection may contribute to schizophrenia pathophysiology.
• Impaired integrity of the left ILF and IFOF is associated with cognitive deficits in schizophrenia.
• These findings are independent of antipsychotic medication effects.