Brain structural changes in regions within the salience network in patients with functional constipation

Area of Science:

• Neuroimaging
• Gastroenterology
• Psychiatry

Background:

• Functional constipation (FCon) is a common functional gastrointestinal disorder (FGID).
• Previous research indicates alterations in brain structure and connectivity in FCon patients.
• The specific impact of FCon on gray matter (GM) volume and structural connectivity (SC) remains incompletely understood.

Purpose of the Study:

• To investigate differences in GM volume and SC in patients with FCon compared to healthy controls (HC).
• To explore the relationship between brain changes, FCon symptoms, and anxiety.

Main Methods:

• Voxel-based morphometry (VBM) was used to analyze GM volume differences.
• Diffusion tensor imaging (DTI) with probabilistic tractography was employed to assess SC.
• 48 FCon patients and 52 HC were included in the study.

Main Results:

• FCon patients exhibited decreased GM volumes in the right middle frontal gyrus (MFG_R), left insula (INS_L), and anterior cingulate cortex (ACC).
• These GM volume reductions were negatively correlated with abdominal symptoms and difficulty of defecation.
• SC analysis revealed decreased fractional anisotropy in tracts connecting the ACC-MFG and INS-MFG in FCon patients.
• Abdominal symptoms positively correlated with anxiety scores (SAS).

Conclusions:

• FCon is associated with significant alterations in GM volume within the salience network.
• Reduced SC in specific brain tracts is linked to FCon.
• These findings highlight the neurobiological underpinnings of functional constipation and its connection to psychological factors.