Investigating cerebral blood flow dysregulation and serum zinc correlation in 2-4 year-old children with autism spectrum disorder.

Researchers studied blood flow in the brains of young children with autism using special brain scans. They found that children with more severe autism had reduced blood flow in several important brain areas compared to children without autism. They also discovered that blood flow patterns were different between the left and right sides of one brain region called the thalamus. Interestingly, children with higher zinc levels in their blood had better blood flow in certain brain areas.

This cross-sectional neuroimaging study examined cerebral blood flow (CBF) patterns in 121 children aged 2-4 years, including 76 with autism spectrum disorder (16 severe, 60 mild-moderate) and 45 typically developing controls. Using 3D-pCASL imaging, researchers measured CBF across nine brain regions. Children with severe autism showed significantly reduced CBF in temporal lobe, putamen, thalamus, and hippocampus compared to typically developing children. Severe cases also demonstrated further CBF reductions in putamen and thalamus compared to mild-moderate autism.

Both autism groups showed asymmetrical thalamic blood flow, with lower flow in the left thalamus. A positive correlation was identified between thalamic CBF and serum zinc levels in autistic children, suggesting potential biomarker applications for severity stratification.

3D-pCASL neuroimaging may provide objective biomarkers for autism severity stratification in young children. Reduced cerebral blood flow patterns could inform early intervention targeting. The zinc-CBF correlation warrants investigation of nutritional factors in autism management, though clinical significance remains unclear.

Cross-sectional design prevents determination of causality. Single-center study may limit generalizability. Correlation between zinc and CBF requires replication. No information provided about medication effects or comorbidities that could influence cerebral blood flow patterns.

Autism spectrum disorder (ASD) is a severe neurodevelopmental condition. Its incidence is on the rise worldwide, and in severe cases, it can lead to disability. While emerging evidence implicates cerebrovascular dysfunction in the pathophysiology of neurodevelopmental impairments associated with ASD, systematic characterization of cerebral hemodynamic variations across clinically stratified severity subgroups, particularly among mild-moderate and severe ASD presentations and typically developing (TD) children, remains a critical unmet research need. This cross-sectional neuroimaging study enrolled 121 children aged 2 to 4 years: 16 with severe autism (Childhood Autism Rating Scale (CARS) score > 36), 60 with mild-moderate autism (CARS score between 30 and 36), and 45 TD children.

CBF measurements were obtained from nine regions of interest (ROI) in both hemispheres: temporal lobe, parietal lobe, occipital lobe, putamen, thalamus, caudate nucleus, globus pallidus, hippocampus, and amygdala. Intergroup comparisons of CBF values were performed among the three groups. Particular emphasis was placed on analyzing the correlation between thalamic CBF values and serum zinc levels in autistic children. Children with severe autism exhibited significantly lower CBF in the temporal lobe, putamen, thalamus, and hippocampus compared to TD children (p < 0.05).

Within the autism cohort, severe cases demonstrated further CBF reductions in the putamen and thalamus compared to mild-moderate cases (p < 0.05). Similarly, children with mild-moderate autism showed reduced CBF in the temporal lobe, putamen, thalamus, and hippocampus compared to TD children (p < 0.05). Notably, a significant difference in CBF was observed between the left and right thalamus in both mild-moderate and severe autism groups, with lower blood flow in the left thalamus (p < 0.05). A positive correlation was found between thalamic CBF values and serum zinc levels in the autism group.

Children with severe autism show significantly reduced CBF in critical brain regions. Thus, 3D-pCASL may enable the precise stratification of ASD severity in children and provide an imaging foundation for subsequent therapeutic evaluation.