Functional connectivity in autism spectrum disorder evaluated using rs-fMRI and DKI

Area of Science:

• Neuroimaging
• Autism Spectrum Disorder Research
• Brain Connectivity

Background:

• Autism spectrum disorder (ASD) is a complex neurodevelopmental condition.
• Understanding the neural underpinnings of ASD is crucial for developing targeted interventions.
• Previous research suggests alterations in brain structure and function in individuals with ASD.

Purpose of the Study:

• To investigate functional connectivity (FC) and white matter (WM) microstructural integrity in adults with ASD.
• To explore the relationship between WM integrity, measured by diffusion kurtosis imaging (DKI), and FC, measured by resting-state functional MRI (rs-fMRI).
• To identify specific brain regions and pathways affected by altered connectivity in ASD.

Main Methods:

• Acquired rs-fMRI data from 33 adults with ASD and 33 healthy controls (HC).
• Acquired DKI data from 18 adults with ASD and 17 HC.
• Analyzed FC differences between ASD and HC groups, and DKI metrics in WM tracts.

Main Results:

• ASD showed attenuated FC between the right frontal pole and temporal fusiform cortex.
• ASD exhibited enhanced FC between the right thalamus and occipital cortex, and cerebellum and occipital/lingual gyri.
• Increased DKI metrics (axial kurtosis and mean kurtosis) were observed in WM tracts (e.g., anterior corona radiata, forceps minor, superior longitudinal fasciculus) in ASD.
• A negative correlation was found between DKI metrics and FC in specific WM tracts in ASD.

Conclusions:

• Altered FC patterns in ASD may be linked to microstructural abnormalities in WM tracts.
• Increased DKI metrics in ASD might indicate neuroinflammation, increased complexity, or disrupted WM integrity.
• These microstructural changes potentially impact long-range brain connectivity in individuals with ASD.