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Probing the Brain in Autism Using fMRI and Diffusion Tensor Imaging
Published on: September 12, 2011
Abnormal brain size effect on the thalamus in autism
Antonio Y Hardan1, Ragy R Girgis, Jason Adams
1Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA. hardanay@upmc.edu
Psychiatry Research
|September 2, 2006
Summary
This study found that brain size does not affect thalamus volume in individuals with autism, unlike in healthy controls. This suggests potential abnormal brain connections in autism spectrum disorder.
Area of Science:
- Neuroscience
- Developmental Neuroscience
- Autism Spectrum Disorder Research
Background:
- Previous research suggested a link between brain volume and thalamus size in healthy individuals, but not in those with autism.
- Replication in a larger sample was needed to confirm these findings regarding brain size effects on the thalamus in autism.
Purpose of the Study:
- To examine thalamus volume in autism spectrum disorder (ASD).
- To investigate the influence of total brain volume (TBV) on thalamus volume in ASD.
- To explore correlations between thalamic volumes and clinical features in individuals with ASD.
Main Methods:
- Volumetric MRI scans were analyzed for 40 high-functioning individuals with autism and 41 healthy controls.
- Measurements included right and left thalamic nuclei volumes.
- Statistical analyses examined group differences and relationships between TBV, thalamic volume, and clinical features.
Main Results:
- No significant differences in unadjusted thalamic volumes were found between the autism and control groups.
- The expected linear relationship between total brain volume (TBV) and thalamic volume was absent in individuals with autism.
- No correlations were identified between thalamic volumes and clinical characteristics in the autism group.
Conclusions:
- Findings support previous reports of an abnormal brain size effect on the thalamus in autism.
- The results suggest potential disruptions in cortical-subcortical structural connectivity in autism spectrum disorder.
- This larger study reinforces the understanding of neuroanatomical differences in autism.
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