Abstracts

Rationale: An increased prevalence of epilepsy and abnormal EEG's in autistic children has been described. Epileptiform EEG abnormalities are present in 10.3-72.4% of patients and interictal EEG abnormalities in 6.1-31%. The relationship between epilepsy, epileptiform discharges without clinical seizures and cognitive language and behavioral symptoms is poorly understood. It is hypothesized that epileptiform activity is associated with adverse cognitive manifestations in children with ASD. Since difficulties with socialization, and maladaptive behaviors are often found in autistic children, we inquire whether the presence of these behaviors indicates an underlying cerebral irritability or abnormal structural network that gives rise to epileptiform discharges. Methods: The EEG database at the Women and Children's Hospital of Buffalo was reviewed, and out of 22,715 EEGs performed between 1999-2006, 123 were children with ASD. EEG abnormalities were found in 39 (31%). A control group of age and gender matched patients with normal EEGs was also obtained. Inclusion criteria: primary ASD, age above 4 years. Exclusion criteria: any concomitant disorder which would account for the autistic features. Packets mailed to families included 1) the Vineland Adaptive Behavior Scale II, 2) the Aberrant Behavior Checklist. On follow up telephone interview, the Childhood Autism Rating Scale (CARS) was administered to confirm diagnosis of ASD. Of 21 packets received, 11 had normal EEGs and 10 were abnormal. Results: There were no statistically significant differences in behavior when comparing normal to abnormal EEG findings. However, children with ASD and seizures had statistically significant lower scores in Daily living (p=0.009) and Socialization (p=0.007) than children without seizures. ASD children with seizures also had higher levels of hyperactivity and irritability compared to ASD children without seizures. Differences in irritability scores nearly reached statistical significance (p=0.058). In the statistical analysis, there was no significant difference in the degree of autism between the groups. Conclusions: Lack of statistically significant differences in behaviors when comparing normal to abnormal EEG findings may be due to the small sample size and possible parental bias. The presence of the significant findings of lower daily living, socialization scores, higher hyperactivity, irritability scores in patients with ASD and seizures could possibly be due to the impairment of quality of life and cognitive impairment that seizures have induced in the ASD population. Perhaps the increased level of neuronal irritability which causes the manifestation of the seizures is the same as that which causes the behaviors. This may lead to the conclusion that seizures (and not the EEG abnormalities that are found) are interconnected to the neurological disorder which causes certain behaviors. Clinically this may aid physicians in when to use EEG as a screening tool in children with ASD.