Autism may be linked to an excess of neurons in a child's brain according to a SMALL study:
the brains of seven deceased autistic children were compared with the brains of six deceased kids who didn't have autism. The autistic kids had, on average, 67% more neurons — a type of brain cell and a building block of the nervous system — than boys without autism at a similar age. These neurons were concentrated in the prefrontal cortex, which is key to complex thoughts and behaviors, including language, social behavior and decision-making. The brains of autistic children were also found to be heavier, weighing an average of 17% more than the brains of kids without autism.
What does it mean?
Neurons are only generated during development in the womb. Thus, this study lends compelling evidence to the argument that autism has something of a prenatal origin — and is not something triggered during early childhood. In the future, brain size could have a large impact on future autism screening. Pediatricians, for instance, might flag children with abnormally large brains as potential victims of the disease earlier than they do now, and be able to start treatment sooner.