The prevalence of autistic spectrum disorder (ASD) among 519 patients with epilepsy, and the clinical characteristics of patients with both pathologies were analyzed retrospectively at Saga University, Japan. Of 79 (15.2%) patients with epilepsy and ASD, 62 patients had idiopathic ASD and 17 had secondary ASD. Male preponderance was 47 to 15 females; median age 11 years (range 2 to 43 years). Age at onset of seizures was most frequently 4 years; 85% occurred before 10 years of age. ASD was detected after onset of epilepsy in 29 cases (46.8%), and the diagnosis was delayed for >5years in 8, mostly high-functioning ASD cases. Complex partial seizure was the most frequent pattern, occurring in 68%. Paroxysmal activities in the EEG were frontal in half the cases. Response to AEDs was complete for more than 2 years in 67.3% patients. Autistic symptoms improved after epilepsy treatment in 5 cases (8%). 
COMMENT. Epilepsy associated with ASD is usually characterized by complex partial seizures with frontal paroxysms with onset from 1 to 9 years of age. The prevalence of epilepsy with ASD in this study was 15%, lower than some previous reports of 20% to 46% in different populations.
An International Symposium on Epilepsy in ASDs and related conditions, edited by Dr Yukio Fukuyama and colleagues, was the topic at the 12th Annual Meeting of the Infantile Seizure Society held in Kurume, Japan, May 9-10, 2009. Several review and original articles are published in the October issue of Brain Dev 2010;32:695-780).
Dr Amy Brooks-Kayal of University of Colorado Denver School of Medicine reviews the common genetic, molecular and cellular developmental mechanisms of ASD and epilepsy. (Brain Dev Oct 2010;32:731-738). Genetic disorders sharing epilepsy and autism include tuberous sclerosis, Rett syndrome, and fragile X. Various mutations of several genes involved in neurodevelopment are found in both disorders. Early life seizures can result in cellular and molecular changes in the hippocampus that contribute to learning and behavior disorders as seen in ASD. The excitatory-inhibitory imbalance resulting from these factors may represent new therapeutic targets for treatment.