ABSTRACT
Brain is the final pathway to which all the etiological factors discussed in the last chapter lead. There is sufficient evidence in the neuroscience literature that autistic symptoms occur because of functional or structural abnormalities of the brain. About 15-30% of children with autism have macrocephaly (1-5), due to larger brain volume (6, 7), with increases in both gray and white matter (8). While autistic individuals continue to have a larger head circumference throughout their life, their brain volume decreases after increasing for a few years after birth (8-10), suggesting a neuropathological process that begins before birth but continues postnatally. Increased head circumference in autism is not correlated with IQ, verbal ability, seizure disorder, or autistic symptoms.
