Which of the neurological-biochemical abnormalities is associated with autistic disorder?

Ans. D. All of the aboveEvidence exists demonstrating associations between autistic disorder and a variety of biological abnormalities. Estimates of lifetime occurrence of grand mal seizures ranges between 4 and 32 percent. Recent neuroimaging studies suggest a pattern of increased and then decreased rate of brain growth over time; increased total brain volume is noted in many individuals with autism. Ventricular enlargement on CT scan is observed in 20 to 25 percent of individuals with autism.Although no EEG findings are specific for autism, abnormalities are common in the disorder; estimates of prevalence of EEG abnormalities range from 10 to 83 percent, and failure of cerebral lateralization is a typical finding.One-third of children with autism demonstrate elevated serum serotonin levels; the significance of this finding is uncertain, particularly given similar rates of hyperserotonemia in children with severe mental retardation.