Originally, 38 brains, including 20 brains of autistic and 18 brains of control subjects, were assigned to this project. However, application of the clinical and neuropathological exclusion criteria reduced the size of the cohort to 27 brains. Based on the results of the ADI-R, two cases were excluded, including one case diagnosed with atypical autism, and one that did not meet ADI-R criteria. Based on postmortem evaluation, five more autistic cases were excluded: one due to severe postmortem autolytic changes, three due to severe global hypoxic encephalopathy related to the mechanism of death, and one due to multiple microinfarcts. Moreover, four brains of control subjects were disqualified due to severe postmortem autolysis. In all these brains, neuronal loss, changes of neuronal size and shape, and gliosis were so severe that they masked and distorted the qualitative and quantitative characteristics of the developmental alterations associated with autism.
