Anomalous cerebral asymmetry and language processing in schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Structural cerebral asymmetries are debated in schizophrenia pathogenesis.
• Early detection of anomalous brain asymmetries is crucial for understanding schizophrenia.
• Investigating the genetic basis of cerebral asymmetries in schizophrenia is important.

Purpose of the Study:

• To determine if anomalous cerebral asymmetries are present at the first episode of schizophrenia.
• To assess if these asymmetries predict language processing deficits.
• To explore the potential genetic predisposition for cerebral asymmetries in schizophrenia.

Main Methods:

• Magnetic resonance imaging (MRI) was used to assess brain width and sylvian fissure asymmetries in 87 first-episode schizophrenia patients and 52 controls.
• Correlations were examined between asymmetries and measures of language processing, memory, and hand skill.
• A sibling study evaluated heritability of cerebral asymmetries in 14 pairs of siblings with schizophrenia.

Main Results:

• Reduced width asymmetries were observed in posterior (p=0.02) and occipital (p=0.05) regions in patients.
• Brain horizontal length was significantly more asymmetrical in patients (left > right; p=0.04).
• Sylvian fissure asymmetry showed trends towards differences between patients and controls (p<0.06), with greater within-pair correlations in siblings, suggesting heritability.

Conclusions:

• Findings suggest the early presence, possibly genetic, of anomalous cerebral asymmetry in schizophrenia.
• Few significant correlations were found between cerebral asymmetries and cognitive performance.
• The functional implications of reduced cerebral asymmetry in schizophrenia remain unclear.