Primal Health Databank: Study
| Entry No: | 0440 |
| Title: | Evidence of brain overgrowth in the first year of life in autism |
| Author(s): | Courchesne E, Carper R, Akshoomoff N, de Klerk N, Chaney G, Hallmayer JF, Dean JC |
| Reference: | JAMA. 2003 Jul 16;290(3):337-44 |
| Place of Study: | USA |
| Abstract: | The objective of this study was to determine whether pathological brain overgrowth precedes the first clinical signs of autism spectrum disorder (ASD) and whether the rate of overgrowth during the first year is related to neuroanatomical and clinical outcome in early childhood. Head circumference (HC), body length, and body weight measurements during the first year were obtained from the medical records of 48 children with ASD aged 2 to 5 years who had participated in magnetic resonance imaging studies. Of these children, 15 (longitudinal group) had measurements at 4 periods during infancy: birth, 1 to 2 months, 3 to 5 months, and 6 to 14 months; and 33 (partial HC data group) had measurements at birth and 6 to 14 months (n = 7), and at birth only (n = 28).
Age-related changes in infants with ASD who had multiple-age measurements, and the relationship of these changes to brain anatomy and clinical and diagnostic outcome at 2 to 5 years were evaluated by using 2 nationally recognized normative databases: cross-sectional normative data from a national survey and longitudinal data of individual growth. Compared with normative data of healthy infants, birth HC in infants with ASD was significantly smaller (z = -0.66, P<.001); after birth, HC increased 1.67 SDs and mean HC was at the 84th percentile by 6 to 14 months. Birth HC was related to cerebellar gray matter volume at 2 to 5 years, although the excessive increase in HC between birth and 6 to 14 months was related to greater cerebral cortex volume at 2 to 5 years. Within the ASD group, every child with autistic disorder had a greater increase in HC between birth and 6 to 14 months (mean [SD], 2.19 [0.98]) than infants with pervasive developmental disorder-not otherwise specified (0.58 [0.35]). Only 6% of the individual healthy infants in the longitudinal data showed accelerated HC growth trajectories (>2.0 SDs) from birth to 6 to 14 months; 59% of infants with autistic disorder showed these accelerated growth trajectories. The authors conclude that the clinical onset of autism appears to be preceded by 2 phases of brain growth abnormality: a reduced head size at birth and a sudden and excessive increase in head size between 1 to 2 months and 6 to 14 months. Abnormally accelerated rate of growth may serve as an early warning signal of risk for autism. |
| Keyword(s): | autism, autistic spectrum disorder, fetal growth, head circumference, labor induction, labour induction, obstetric medication, preeclampsia, Rhesus-immunization |
| Discussion: | No discussion mentioned for this entry |
| See Also: | No related entries mentioned for this entry |
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