White matter integrity and its correlation with symptom severity in adolescents with high-functioning autism spectrum disorder.

This brain imaging study looked at the white matter (brain connections) in 42 autistic teenagers compared to 56 non-autistic teenagers. They found differences in brain connectivity patterns, with some areas showing stronger connections and others weaker connections. Importantly, certain brain connection differences were linked to language difficulties and sensory processing challenges commonly seen in autism.

This DTI study examined white matter integrity in 42 high-functioning autistic adolescents compared to 56 typically developing controls. Results showed complex patterns of both increased and decreased fractional anisotropy across multiple brain regions including cerebellar peduncles, corticospinal tracts, and association pathways. Notably, white matter alterations in the uncinate fasciculus correlated with language function, while middle cerebellar peduncle changes correlated with sensory abilities. These findings suggest that disrupted white matter connectivity may underlie both neurological and clinical manifestations of autism, providing potential neurobiological markers for symptom severity.

Findings suggest white matter integrity measures could serve as potential neurobiological markers for autism symptoms. Correlations between brain connectivity and specific functional domains (language, sensory processing) may inform targeted interventions and assessment approaches.

Single-center study with moderate sample size. Cross-sectional design prevents causal inferences. Limited to high-functioning autism, reducing generalizability. Inconsistencies with previous DTI findings in autism suggest methodological variability may affect results.

Increasing evidence links disrupted brain connectivity to autism spectrum disorder (ASD), with white matter alterations as a core mechanism. Diffusion tensor imaging (DTI) has detected white matter abnormalities in ASD, but findings lack consistency, and few studies have correlated these abnormalities with clinical symptoms. Forty-two high-functioning ASD (HFASD) adolescents and 56 matched typically developing (TD) controls underwent DTI scans, analyzed via tract-based spatial statistics (TBSS) for fractional anisotropy (FA) changes. HFASD participants were assessed for symptom severity using the Autism Behavior Checklist (ABC), with voxel-wise correlation analyzing FA-symptom relationships in regions showing group differences.

Compared to TD controls, HFASD adolescents exhibited increased FA in bilateral inferior cerebellar peduncle (ICP) and corticospinal tract (CT), and decreased FA in bilateral ICP, middle cerebellar peduncle (MCP), uncinate fasciculus (UF), plus left anterior corona radiata (ACR), inferior fronto-occipital fasciculus (IFOF), superior longitudinal fasciculus (SLF), and CT (all P < 0.005, TFCE-corrected). Correlation analysis revealed FA alterations in left/right UF correlated with language function (R=0.57/0.49, P < 0.005, TFCE-corrected), while right MCP FA changes correlated with sensory ability (R=-0.64, P < 0.005, TFCE-corrected). These findings indicate white matter integrity abnormalities may underpin ASD's neuropathological and clinical basis.