Brain enlargement is associated with regression in preschool-age boys with autism spectrum disorders

Abstract

Autism is a heterogeneous disorder with multiple behavioral and biological phenotypes. Accelerated brain growth during early childhood is a well-established biological feature of autism. Onset pattern, i.e., early onset or regressive, is an intensely studied behavioral phenotype of autism. There is currently little known, however, about whether, or how, onset status maps onto the abnormal brain growth. We examined the relationship between total brain volume and onset status in a large sample of 2-to 4-yold boys and girls with autism spectrum disorder (ASD) [n = 53, no regression (nREG); n = 61, regression (REG)] and a comparison group of age-matched typically developing controls (n = 66). We also examined retrospective head circumference measurements from birth through 18 mo of age. We found that abnormal brain enlargement was most commonly found in boys with regressive autism. Brain size in boys without regression did not differ from controls. Retrospective head circumference measurements indicate that head circumference in boys with regressive autism is normal at birth but diverges from the other groups around 4-6 mo of age. There were no differences in brain size in girls with autism (n = 22, ASD; n = 24, controls). These results suggest that there may be distinct neural phenotypes associated with different onsets of autism. For boys with regressive autism, divergence in brain size occurs well before loss of skills is commonly reported. Thus, rapid head growth may be a risk factor for regressive autism.MRI | neurodevelopment | trajectory | macrocephaly

Biochemical screening and PTEN mutation analysis in individuals with autism spectrum disorders and macrocephaly

“…7,18 Although macrocephaly has been reported in 15-35% of children with an ASD, and is the most frequent physical finding, 7 it is also observed in B2% of healthy individuals and others who do not meet DSM-IV-TR criteria. Several genetic and non-genetic conditions are associated with macrocephaly and include benign familial macrocephaly, cancer predisposition syndromes, and metabolic disorders.…”

Use and Perceived Effectiveness of Complementary and Alternative Medicine to Treat and Manage the Symptoms of Autism in Children: A Survey of Parents in a Community Population

“…20 Additionally, the sex distribution among the children with ASD (78.4% male), the proportion of sleep problems (49.0%), the history of regression into ASD (61.9%), and the use of CAM (80.9%) were also similar to the findings from other studies. 1,14,19,21 Why do parents turn to CAM treatments for their children with ASD? The reasons are many and varied, but CAM may be used for the following reasons:…”

Clinical Motor and Cognitive Neurobehavioral Relationships in the Basal Ganglia

“…This greater caudate volume was proportional to the increased total brain volume and enlargement of other brain structures earlier reported in the patients with autism. [65].…”