Epilepsy occurred in 27% (14/52) of children with autism under 10 years of age in a population-based study in the Dept of Child and Adolescent Psychiatry and Pediatrics, University of Goteborg, Sweden. Psychomotor seizure patterns in 71% of those with epilepsy were associated with temporal lobe EEG focal abnormalities. Infantile spasms and hypsarrhythmia occurred in 3 cases. Organic brain factors included perinatal asphyxia or hemorrhage, progressive encephalopathy, fragile X syndrome and tuberous sclerosis. The authors conclude that autistic behavior and epilepsy probably reflect underlying brain dysfunction and are not causally related. 
COMMENT. The association of autistic behavior with epilepsy and mental retardation in children is not uncommon. Some have a previous history of infantile spasms caused by tuberous sclerosis. In this group of cases the epilepsy is primary and the autism secondary. The authors of the above study correctly distinguish between these cases referred to as autistic-like conditions and those in whom infantile autism is primary and precedes the development of epilepsy.
Adults with left-sided epileptogenic temporal lobe lesions may be at a greater risk of developing schizophrenia-like psychoses than those with right-sided lesions . A review of the EEG findings in children with autism and epilepsy in the above study showed that of 10 with temporal lobe foci, 5 were left-sided, 4 right-sided and 1 bilateral. Of the 5 with left-sided foci, 3 had infantile autism and 2 were classifed as autistic-like in behavior.