Evaluation of Brain Microstructural Alterations in Preschool Autism Spectrum Disorder: A Voxel-Wise Multimodal MRI Study.

Researchers used advanced brain scans to study 29 preschool children with autism compared to 25 typical children. They found differences in two key areas: lower iron levels in the front part of the brain and changes in the coating around nerve fibers in movement-related brain regions. These brain differences were linked to motor skill challenges - children with lower iron had more fine motor difficulties, while those with nerve coating changes had more gross motor problems. The brain scan patterns were very accurate at identifying autism.

This advanced neuroimaging study examined brain microstructure in 29 preschool children with autism (ages 2-6) compared to 25 matched controls using multimodal MRI techniques. Key findings revealed reduced iron levels (decreased QSM values) in left frontal brain regions and altered myelination patterns (decreased T1 relaxation times) in bilateral frontal and sensorimotor areas in children with autism. These brain differences strongly correlated with motor function deficits - iron deficiency in frontal regions linked to fine motor skills, while myelination changes in sensorimotor areas correlated with gross motor abilities. The imaging markers demonstrated high diagnostic accuracy (85-91% area under curve), suggesting potential biomarker utility for early autism identification.

Findings suggest potential neuroimaging biomarkers for early autism identification with high diagnostic accuracy. The strong correlation between brain microstructural changes and motor deficits supports targeted motor interventions in preschool autism. However, clinical translation requires validation in larger, diverse samples and assessment of longitudinal stability of these markers.

Small sample size (29 ASD participants) limits generalizability. Cross-sectional design prevents understanding of developmental trajectories. Study focused only on preschool age group, limiting applicability to other developmental stages. Advanced neuroimaging techniques require specialized equipment and expertise not widely available in clinical settings.

Autism Spectrum Disorder (ASD) presents with early neurodevelopmental alterations in preschool children, yet comprehensive characterization using multimodal quantitative MRI remains limited in this age group. To investigate voxel-wise brain microstructural differences in preschool ASD through integrated analysis of cerebral perfusion, multiparametric relaxometry, and magnetic susceptibility. Prospective case-control. Twenty nine-children with ASD (age 2-6 years; 23 males/6 females) and 25 age-/sex-matched healthy controls (HC). 3.0 T MRI; high-resolution 3D-T1WI, quantitative susceptibility mapping (QSM), synthetic MRI (SyMRI), 3D pseudo-continuous arterial spin labeling (3D-pCASL).

Clinical assessments included the Gesell Developmental Schedules (GDS) and Childhood Autism Rating Scale (CARS). Imaging analysis consisted of voxel-wise whole-brain assessment of QSM, T1/T2/PD, and cerebral blood flow (CBF) maps. General linear models with cluster-based thresholding were applied for group comparison; Spearman's rank correlation with Bonferroni correction was used for clinical associations; and receiver operating characteristic (ROC) analysis with Delong's test was performed to compare diagnostic performance based on the areas under the curve (AUCs). Compared to HC, children with ASD showed decreased QSM values in the left superior/middle frontal gyri (SFG/MFG; cluster = 212 voxels, peak T = 5.55, p < 0.001).

They also had reduced T1 relaxation times in bilateral SFG/MFG/precentral/postcentral gyri (four clusters: 315-750 voxels, peak T = 5.11-5.88, all p < 0.001). QSM values in the left SFG/MFG correlated positively with fine motor scores (r = 0.630, p < 0.001), while T1 values in the bilateral precentral/postcentral gyri correlated with gross motor scores (right: r = 0.548, p = 0.002; left: r = 0.461, p = 0.012). ROC analysis showed high diagnostic accuracy for both QSM (left SFG/MFG AUC = 0.858) and T1 values (left SFG/MFG AUC = 0.905; bilateral precentral/postcentral gyri AUC = 0.892-0.908). Preschool ASD demonstrates prefrontal iron deficiency (reduced QSM) and sensorimotor myelination alterations (decreased T1), which correlate with motor deficits and show high diagnostic efficacy. 2 Stage 2.