Alterations in microarchitecture and network integrity in diffusion tensor images of children with marginal...

Area of Science:

• Neuroimaging
• Developmental Neuroscience
• Cognitive Neuroscience

Background:

• Intellectual disability (ID) and marginal intelligence (MI) are associated with neurodevelopmental challenges.
• Understanding the underlying structural brain abnormalities is crucial for targeted interventions.

Purpose of the Study:

• To investigate structural brain damage in fiber bundles and neural networks in children with MI or ID using Diffusion Tensor Imaging (DTI).
• To compare DTI-derived measures between healthy controls and children with MI, ID, and comorbid ID with ADHD.

Main Methods:

• Acquisition of 3.0 Tesla MRI scans with DTI sequences from 30 healthy children, 25 with MI, 35 with ID, and 32 with ID and ADHD.
• Analysis of DTI data using correlation tractography, network measures, and graph visualizations to assess white matter integrity and brain network topology.

Main Results:

• Children with MI, ID, or ID+ADHD exhibited damage in key white matter tracts including arcuate fasciculi, superior longitudinal fasciculi, and thalamic radiations.
• Significant reductions in network density, global efficiency, and rich club coefficient were observed in MI, ID, and ID+ADHD groups compared to controls.
• Progressive loss of critical brain network nodes was noted in frontal and temporal regions, worsening from MI to ID, with or without ADHD.

Conclusions:

• Children with MI, ID, or comorbid ID and ADHD display significant morphological abnormalities in fiber tracts and disrupted neural network connectivity.
• DTI-based connectome analysis reveals a progressive decline in hub node integrity with increasing intellectual impairment severity.
• These findings highlight the pervasive impact of intellectual disability on brain structure and network function.