Article

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

ABSTRACT

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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    • "The rs2254298-A allele of OXTR was associated with sociability and increased amygdala volume[Brune, 2012]. In addition, the amygdala was observed to be enlarged in individuals with ASD[Mosconi et al., 2009]. Interestingly , similar volumetric aberrations were observed in anxiety disorders, a frequent comorbidity among ASD cases[Kleinhans et al., 2011]. "
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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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    • "In contrast, amygdala volumes only differed concerning the life-span trajectories: Unlike the control persons, who displayed increasing amygdala volumes over time, persons with ASD (on a trend level) showed a decrease of bilateral amygdala volumes. The result of differing time-trajectories of amygdala volumes fits to the pattern of former findings, reporting enlarged amygdala volumes in smaller children with ASD (Sparks et al., 2002; Mosconi et al., 2009; Schumann et al., 2009), reduced amygdala volumes in adolescents and adults with ASD (Aylward et al., 1999; Nacewicz et al., 2006), and an age-dependent increase of amygdala volumes in controls but not in persons with ASD (Murphy et al., 2012). "
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