Abstracts

Rationale: Sedated electroencephalogram (EEG) is frequently ordered in children on the autism spectrum. Though largely a safe test, considerations like possibility of adverse reaction to sedation, healthcare costs and practical utility exist. The purpose of this study is to assess the diagnostic value of sedated EEGs in the pediatric autistic population. We also assessed if there was a change in the patient management solely based on the results of the sedated EEG.Methods: Retrospective chart review on all patients who had sedated EEGs done at our pediatric center from January 2007 to March 2013 was conducted. Based on the indication for ordering the study, two groups were identified. Patients with event/events with clear seizure semiology based on the ordering neurologist s notes were classified under Seizure group. All behavior indications like staring spells, abnormal behavior, stereotypic motor movements, and language regression were grouped as Other . Sedated EEG was labeled Positive if the report described focal slowing or epileptiform discharges. We looked at the correlation of positive sedated EEG finding with MRI abnormalities and the indication for the test (seizure versus other). We also reviewed the treating neurologist s follow up visits from the charts to determine if a change in treatment was made, before or after results of the sedated EEG. Statistical analyses were performed using Chi square and Fisher's Exact tests. Results: A total of 200 patients underwent sedated EEG study during the selected period. 97 were excluded due to inadequate documentation or were lost to follow up. Out of the 103 charts included, 80 were autistic (77.7%).11 autistic patients had EEG positive(13.75 %). Indication for ordering the test was Seizure in 61/103 (59.2%) and Other in 42/103 children (40.77%). Sedated EEG was negative in all patients with the indication as Other (95% confidence interval -0% to 6.9%).18 out of 61 (29.5%) in the group with indication as seizure had sedated EEG positive (95% CI -18.5% to 42.6 %).There was a significant association between indication of the test and sedated EEG (p value < 0.0001). No association between sedated EEG and autism were found (p value 0.11).19/80(23.7%) autistic patients had MRI abnormalities, out of which only 1 had EEG positive. Out of the 80 autistic patients, 73 ( 91.25. %) had no change in management after sedated EEG. 35/80(43.7% ) autistic patients were started on medication before sedated EEG results .Conclusions: Utility of sedated EEG was strongly correlated to the indication for ordering the test. Majority of the medical management change occurred before the test, based on the treating neurologist s clinical index of suspicion for seizures. Sedated EEG obtained for other indications was not a useful test.