Source-based morphometry reveals distinct patterns of aberrant brain volume in delusional infestation

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Delusional infestation (DI) is a rare disorder characterized by the false belief of being infested with pathogens.
• Existing research on DI's neural underpinnings relies heavily on case reports and series.
• Understanding the brain morphology associated with DI is crucial for diagnosis and treatment.

Purpose of the Study:

• To investigate the brain morphology differences between individuals with delusional infestation and healthy controls.
• To identify specific patterns of grey and white matter abnormalities in DI patients.
• To explore how disease aetiology influences brain structure in DI.

Main Methods:

• Utilized structural magnetic resonance imaging (sMRI) to assess brain morphology.
• Employed source-based morphometry (SBM), a multivariate technique, for data analysis.
• Compared brain structure in 16 DI patients and 16 healthy controls, including subgroup analysis based on aetiology.

Main Results:

• Source-based morphometry revealed significant differences in grey and white matter volumes between DI patients and controls.
• DI patients exhibited lower grey matter volume in prefrontal, cingulate, temporal, sensorimotor, insular, thalamic, and parietal regions.
• Higher white matter volume was observed in frontal, temporal, insular, and striatal areas; aberrant white matter was specific to organic DI.
• Grey matter abnormalities were present in both psychiatric and organic DI subgroups.

Conclusions:

• The findings suggest widespread prefrontal, temporal, parietal, insular, thalamic, and striatal dysfunction in delusional infestation.
• Shared grey matter abnormalities indicate common neural pathways across different DI aetiologies.
• Aberrant white matter volume appears to be a distinguishing feature of organic DI cases.