Dissociating Regional Gray Matter Density and Gray Matter Volume in Autism Spectrum Condition

Background. To establish whether high-functioning children with autism spectrum disorder (ASD) have enlarged brains in later childhood, and if so, whether this enlargement is confined to the gray and/or to the white matter and whether it is global or more prominent in specific brain regions.Method. Brain MRI scans were acquired from 21 medication-naive, high-functioning children with ASD between 7 and 15 years of age and 21 comparison subjects matched for gender, age, IQ, height, weight, handedness, and parental education, but not pubertal status.Results. Patients showed a significant increase of 6% in intracranium, total brain, cerebral gray matter, cerebellum, and of more than 40% in lateral and third ventricles compared to controls. The cortical gray-matter volume was evenly affected in all lobes. After correction for brain volume, ventricular volumes remained significantly larger in patients.Conclusions. High-functioning children with ASD showed a global increase in gray-matter, but not white-matter and cerebellar volume, proportional to the increase in brain volume, and a disproportional increase in ventricular volumes, still present after correction for brain volume. Advanced pubertal development in the patients compared to the age-matched controls may have contributed to the findings reported in the present study.

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Physical Aggressiveness and Gray Matter Deficits in Ventromedial Prefrontal Cortex

10.31234/osf.io/tzvrx ◽

2017 ◽

Author(s):

David Skylan Chester ◽

Donald Lynam ◽

Richard Milich ◽

C. Nathan DeWall

Keyword(s):

Prefrontal Cortex ◽

Gray Matter ◽

Physical Aggression ◽

Gray Matter Volume ◽

Verbal Aggression ◽

Matter Density ◽

Ventromedial Prefrontal Cortex ◽

Normal Female ◽

Gray Matter Density ◽

Normal Individuals

What causes individuals to hurt others? Since the famous case of Phineas Gage, lesions of the ventromedial prefrontal cortex (VMPFC) have been reliably linked to physically aggressive behavior. However, it is unclear whether naturally-occurring deficits in VMPFC, among normal individuals, might have widespread consequences for aggression. Using voxel based morphometry, we regressed gray matter density from the brains of 138 normal female and male adults onto their dispositional levels of physical aggression, verbal aggression, and sex, simultaneously. Physical, but not verbal, aggression was associated with reduced gray matter volume in the VMPFC and to a lesser extent, frontopolar cortex. Participants with less gray matter density in this VMPFC cluster were much more likely to engage in real-world violence. These findings suggest that even granular deficits in normal individuals’ VMPFC gray matter can promote physical aggression.

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Mapping Progressive Gray Matter Alterations in Early Childhood Autistic Brain

Cerebral Cortex ◽

10.1093/cercor/bhaa304 ◽

2020 ◽

Author(s):

Xiaonan Guo ◽

Xujun Duan ◽

John Suckling ◽

Jia Wang ◽

Xiaodong Kang ◽

...

Keyword(s):

Early Childhood ◽

Gray Matter ◽

Gray Matter Volume ◽

Autism Spectrum ◽

Brain Network ◽

Social Brain ◽

Structural Alterations ◽

Matter Volume ◽

Age Related ◽

The Social

Abstract Autism spectrum disorder is an early-onset neurodevelopmental condition. This study aimed to investigate the progressive structural alterations in the autistic brain during early childhood. Structural magnetic resonance imaging scans were examined in a cross-sectional sample of 67 autistic children and 63 demographically matched typically developing (TD) children, aged 2–7 years. Voxel-based morphometry and a general linear model were used to ascertain the effects of diagnosis, age, and a diagnosis-by-age interaction on the gray matter volume. Causal structural covariance network analysis was performed to map the interregional influences of brain structural alterations with increasing age. The autism group showed spatially distributed increases in gray matter volume when controlling for age-related effects, compared with TD children. A significant diagnosis-by-age interaction effect was observed in the fusiform face area (FFA, Fpeak = 13.57) and cerebellum/vermis (Fpeak = 12.73). Compared with TD children, the gray matter development of the FFA in autism displayed altered influences on that of the social brain network regions (false discovery rate corrected, P < 0.05). Our findings indicate the atypical neurodevelopment of the FFA in the autistic brain during early childhood and highlight altered developmental effects of this region on the social brain network.

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