Not on speaking terms: hallucinations and structural network disconnectivity in schizophrenia

Area of Science:

• Neuroimaging
• Psychiatry
• Neuroscience

Background:

• Auditory verbal hallucinations (AVH) in schizophrenia are associated with functional brain network deficits.
• Previous research indicated fronto-temporal and interhemispheric connectivity issues.

Purpose of the Study:

• To investigate white matter abnormalities in tracts connecting frontal, parietal, and temporal lobes in schizophrenia patients with AVH.
• To correlate white matter integrity with hallucination severity.

Main Methods:

• Diffusion tensor imaging (DTI) combined with tract-based spatial statistics (TBSS).
• Comparison of white matter integrity between schizophrenia patients and healthy controls.
• Analysis of white matter differences between patients with and without current hallucinations.

Main Results:

• Schizophrenia patients exhibited reduced fractional anisotropy (FA) in multiple white matter tracts compared to controls.
• Patients with hallucinations showed decreased FA in specific left-hemisphere tracts (IFOF, uncinate, arcuate, SLF, corpus callosum, cingulate, corticospinal, ATR).
• Hallucination severity negatively correlated with white matter integrity in tracts connecting left frontal to temporal regions and interhemispheric connections.

Conclusions:

• Schizophrenia with AVH is associated with widespread white matter abnormalities.
• These alterations affect brain networks involved in language, emotion, and attention/perception.
• White matter integrity is crucial for modulating hallucination severity.