1331. Predictors of Seizure Outcomes in Children with Rasmussen’s Encephalitis Undergoing Resective Epilepsy Surgery: An Individual Participant Data Meta-Analysis

Authors: H. Westley Phillips, MD; William Harris, BS; Aria Fallah (Los Angeles, CA)

Introduction: Rasmussen’s encephalitis (RE) is a progressive epileptic disorder of one cerebral hemisphere that causes intractable focal seizures, cognitive deterioration, and hemiparesis. RE generally occurs in children, with an annual incidence of approximately 2 in 10 million aged 18 years and younger. Despite improved understanding of the underlying inflammatory process, pharmacologic therapy has failed to provide sustained seizure reduction. With hemispherectomy and its modern variants, 70-90% of children achieve seizure freedom. However,a notable proportion of children incurring the risk of brain surgery, however, seizures persist. Methods: We conducted electronic literature searches of PubMed, Web of Science, and CINAHL for relevant articles from inception to May, 2018. We recorded all relevant preoperative factors reported in articles that may predict seizure outcomes at an individual participant level: sex, age at seizure onset, age at surgery, duration of seizures, side affected, types of seizures, seizure frequency, generalized seizures, number of AEDs, IQ, developmental delay, ictal EEG, interictal EEG, and MRI and our primary outcome was seizure status measured by the Engel Classification scale. Results: A total of 17 papers encompassing 187 patients were identified in the literature. Of those patients undergoing resective the vast majority received hemispheric surgery while only 39 patients underwent resections that were less than hemispheric. Of those receiving respective surgery of any kind, 60.43% achieved seizure freedom while the rest suffered from recurrent seizures. Of those patients achieving seizure freedom, only 6 were found in the less than hemispheric group (15.3%) versus (72.3%) in the hemispheric cohort. Conclusion: RE is a rare disorder in children affecting one cerebral which invariable leads to intractable epilepsy. In these patients, respective surgery, specifically hemispheric surgery leads to positive surgical outcomes however, a large number of these patients will experience recurrent seizures despite surgical intervention.