Correlates of head circumference growth in infants later diagnosed with autism spectrum disorders
ABSTRACT Previous research has demonstrated that children diagnosed with autism spectrum disorder show an abnormal acceleration of head growth during the first year of life. This study attempts to replicate these findings and to determine whether overgrowth is associated with clinical outcome. Measurements of head circumference, body length, and body weight taken during the first 2 years of life were obtained from a sample of 35 children diagnosed with autism spectrum disorder and compared to both national normative data (Centers for Disease Control and Prevention) and a control group of 37 healthy infants. Results demonstrated that compared to national averages, infants who were later diagnosed with autism spectrum disorder had a significantly smaller head circumference at birth to 2 weeks and a significantly larger head circumference by 10 to 14 months. Children with autism spectrum disorder were also significantly longer and heavier beginning at 1 to 2 months. However, when overall length and weight were controlled, head circumference was not bigger in the autistic spectrum disorder group compared to local controls. Correlations between head circumference and clinical outcome were significant for 5 of the 30 clinical variables that were run, suggesting that there appears to be no simple or straightforward relationship between head circumference and clinical outcome. Smaller head circumference at birth to 2 weeks was associated with a greater number of symptoms related to social impairment and a greater total number of autism spectrum disorder symptoms based on the Diagnostic and Statistical Manual of Mental Disorders , Fourth Edition criteria. Larger head circumference at 15 to 25 months was also associated with a greater number of symptoms of social impairment. In addition, greater head circumference change during the first 2 years was associated with poorer performance on the visual reception subtest of the Mullen Scales of Early Learning and a smaller number of stereotyped and repetitive behaviors and interests based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria. These findings support previous findings of accelerated brain growth during the first year of life in autism spectrum disorder and question whether growth factors might contribute to both accelerated brain growth and overall body growth.
- SourceAvailable from: Michelle Lampl
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- "This report contributes a description of head circumference changes across the first year of life to an evidentiary base for further understanding early human development. Data suggesting that head growth may be but one element in processes operational at the whole body level include observations that a pattern of growth characterized not only by a relatively smaller head circumference at birth, followed by rapid subsequent growth, but also by a relatively longer and heavier infant by 3–6 months of age is associated with autism spectrum disorder   . These observations raise questions regarding the mechanisms by which head and body growth might be related, and the nature of the biological system that coordinates normal growth of the whole body. "
ABSTRACT: Rapid growth rates of head circumference and body size during infancy have been reported to predict developmental pathologies that emerge during childhood. This study investigated whether growth in head circumference was concordant with growth in body length. Forty infants (16 males) were followed between the ages of 2 days and 21 months for durations ranging from 4 to 21 months (2616 measurements). Longitudinal anthropometric measurements were assessed weekly (n=12), semi-weekly (n=24) and daily (n=4) during home visits. Individual head circumference growth was investigated for the presence of saltatory patterns. Coincident analysis tested the null hypothesis that head growth was randomly coupled to length growth. Head circumference growth during infancy is saltatory (p<0.05), characterized by median increments of 0.20 cm (95% confidence interval, 0.10-0.30 cm) in 24-h, separated by intervals of no growth ranging from 1 to 21 days. Daily assessments identified that head growth saltations were coupled to length growth saltations within a median time frame of 2 days (interquartile 0-4, range 1-8 days). Assessed at semi-weekly and weekly intervals, an average 82% (SD 0.13) of head growth saltations was non-randomly concordant with length growth (p≤0.006). Normal infant head circumference grows by intermittent, episodic saltations that are temporally coupled to growth in total body length by a process of integrated physiology that remains to be described.Early human development 03/2011; 87(5):361-8. DOI:10.1016/j.earlhumdev.2011.02.001 · 1.93 Impact Factor
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- "Head circumference showed a predominantly cubic growth curve, whereby the head circumference tended to be smaller than the norm at birth and normalized later. This is consistent with some previous studies documenting a decreased head circumference at birth in ASD (Courchesne et al. 2003; Dissanayake et al. 2006; Mraz et al. 2007). Nevertheless, the head circumference did not Fig. 1 Head circumference. "
ABSTRACT: The aims of the current study were to examine whether early growth abnormalities are (a) comparable in autism spectrum disorders (ASD) and other childhood psychiatric disorders, and (b) specific to the brain or generalized to the whole body. Head circumference, height, and weight were measured during the first 19 months of life in 129 children with ASD and 59 children with non-ASD psychiatric disorders. Both groups showed comparable abnormal patterns of growth compared to population norms, especially regarding height and head circumference in relation to height. Thus abnormal growth appears to be related to psychiatric disorders in general and is mainly expressed as an accelerated growth of height not matched by an increase in weight or head circumference.Journal of Autism and Developmental Disorders 01/2011; 41(1):44-54. DOI:10.1007/s10803-010-1026-7 · 3.06 Impact Factor
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- "At birth, head circumference in infants who later develop autism is typically near normal (Lainhart et al., 1997; Courchesne et al., 2007). However, by two years of age, head circumference becomes abnormally enlarged in children with autism (Courchesne et al., 2003; Dementieva et al., 2005; Hazlett et al., 2005; Dawson et al., 2007; Mraz et al., 2007; Webb et al., 2007), which corresponds to the age at which symptoms often become apparent. By the time children with autism reach three or four years of age, cross-sectional MRI studies find that brain volume is abnormally enlarged by ~5–10% (Courchesne et al., 2001; Carper et al., 2002; Sparks et al., 2002; Hazlett et al., 2005). "
ABSTRACT: Cross-sectional magnetic resonance imaging (MRI) studies have long hypothesized that the brain in children with autism undergoes an abnormal growth trajectory that includes a period of early overgrowth; however, this has never been confirmed by a longitudinal study. We performed the first longitudinal study of brain growth in toddlers at the time symptoms of autism are becoming clinically apparent using structural MRI scans at multiple time points beginning at 1.5 years up to 5 years of age. We collected 193 scans on 41 toddlers who received a confirmed diagnosis of autistic disorder at approximately 48 months of age and 44 typically developing controls. By 2.5 years of age, both cerebral gray and white matter were significantly enlarged in toddlers with autistic disorder, with the most severe enlargement occurring in frontal, temporal, and cingulate cortices. In the longitudinal analyses, which we accounted for age and gender effect, we found that all regions (cerebral gray, cerebral white, frontal gray, temporal gray, cingulate gray, and parietal gray) except occipital gray developed at an abnormal growth rate in toddlers with autistic disorder that was mainly characterized by a quadratic age effect. Females with autistic disorder displayed a more pronounced abnormal growth profile in more brain regions than males with the disorder. Given that overgrowth clearly begins before 2 years of age, future longitudinal studies would benefit from inclusion of even younger populations as well as further characterization of genetic and other biomarkers to determine the underlying neuropathological processes causing the onset of autistic symptoms.The Journal of Neuroscience : The Official Journal of the Society for Neuroscience 03/2010; 30(12):4419-27. DOI:10.1523/JNEUROSCI.5714-09.2010 · 6.75 Impact Factor