As part of an autopsy research project, the brains of four autistic
subjects were examined and compared with those of three comparison subjects
without CNS pathology and one with phenytoin toxicity. The cerebellum was
selected for initial investigation because pathognomonic symptoms and
neurophysiological measures suggest that pathology may exist in the
cerebellar-vestibular axis in certain patients. Total Purkinje cell counts
were significantly lower in the cerebellar hemisphere and vermis of each
autistic subject than in the comparison subjects.