Longitudinal Study of Amygdala Volume and Joint Attention in 2- to 4-Year-Old Children With Autism

UNC Neurodevelopmental Disorders Research Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3367, USA.
Archives of general psychiatry (Impact Factor: 14.48). 06/2009; 66(5):509-16. DOI: 10.1001/archgenpsychiatry.2009.19
Source: PubMed


Cerebral cortical volume enlargement has been reported in 2- to 4-year-olds with autism. Little is known about the volume of subregions during this period of development. The amygdala is hypothesized to be abnormal in volume and related to core clinical features in autism.
To examine amygdala volume at 2 years with follow-up at 4 years of age in children with autism and to explore the relationship between amygdala volume and selected behavioral features of autism.
Longitudinal magnetic resonance imaging study.
University medical setting.
Fifty autistic and 33 control (11 developmentally delayed, 22 typically developing) children between 18 and 35 months (2 years) of age followed up at 42 to 59 months (4 years) of age.
Amygdala volumes in relation to joint attention ability measured with a new observational coding system, the Social Orienting Continuum and Response Scale; group comparisons including total tissue volume, sex, IQ, and age as covariates.
Amygdala enlargement was observed in subjects with autism at both 2 and 4 years of age. Significant change over time in volume was observed, although the rate of change did not differ between groups. Amygdala volume was associated with joint attention ability at age 4 years in subjects with autism.
The amygdala is enlarged in autism relative to controls by age 2 years but shows no relative increase in magnitude between 2 and 4 years of age. A significant association between amygdala volume and joint attention suggests that alterations to this structure may be linked to a core deficit of autism.

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    • "• No significant differences in responses to JA S14 ZWAIGENBAUM et al at Univ Of Alberta on October 1, 2015 pediatrics.aappublications.org Downloaded from TABLE 1 Continued Reference Findings Type of Study Sample Ascertainment Outcome Diagnosis Comments Mosconi et al, 36 2009 "
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    • "While the basic architecture of the human amygdala is present at birth (Humphrey, 1968; Ulfig et al., 2003), it does appear to undergo significant structural and functional remodeling and refinement across the infancy, childhood and adolescent stages of development (see Tottenham, 2014; Tottenham & Sheridan, 2009, for a review). While the most rapid postnatal volumetric growth occurs soon after birth (e.g., over 100% increase in volume from 0-1 year followed by a 9% increase from years 1-2, Gilmore et al., 2012; also see Payne et al., 2010; Uematsu et al., 2012), the amygdala continues to increase in volume until 4 years of age in females and 18 years of age in males (Giedd et al., 1996; Mosconi et al., 2009; Nordahl et al., 2012; Schumann et al., 2004). Amygdala physiology also undergoes significant change early in life. "
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