PREDICTORS OF SEIZURE OUTCOMES IN CHILDREN WITH TUBEROUS SCLEROSIS COMPLEX UNDERGOING RESECTION EPILEPSY SURGERY: AN INDIVIDUAL PARTICIPANT DATA META-ANALYSIS

Abstract

<p><strong>Objective</strong>: To perform a systematic review and individual participant data meta-analysis to identify preoperative factors associated with a good seizure outcome in children with Tuberous Sclerosis Complex (TSC) undergoing resective epilepsy surgery.</p> <p><strong>Data sources</strong>: Electronic databases (MEDLINE, EMBASE, CINAHL and Web of Science), archives of major epilepsy and neurosurgery meetings, and bibliographies of relevant articles, with no language or date restrictions.</p> <p><strong>Study selection:</strong> We included case-control or cohort studies of consecutive participants undergoing resective epilepsy surgery that reported seizure outcomes. We performed title and abstract and full text screening independently and in duplicate.</p> <p><strong>Data extraction</strong>: One author performed data extraction which was verified by a second author using predefined data fields including study quality assessment using a risk of bias instrument we developed. We recorded all preoperative factors that may plausibly predict seizure outcomes.</p> <p><strong>Data synthesis</strong>: To identify predictors of a good seizure outcome (i.e. Engel Class I or II) we used logistic regression adjusting for length of follow-up for each preoperative variable.</p> <p><strong>Results</strong>: Of 9863 citations, 20 articles reporting on 181 participants were eligible. Good seizure outcomes were observed in 126 (69%) participants (Engel Class I: 102(56%); Engel class II: 24(13%)). On univariable analysis, absence of generalized seizure semiology (OR=3.1, 95%CI=1.2-8.2, p=0.022), no or mild developmental delay (OR=7.3, 95%CI=2.1-24.7, p=0.001), unifocal ictal scalp electroencephalographic (EEG) abnormality (OR=3.2, 95%CI=1.4-7.6, p=0.008) and EEG/Magnetic resonance imaging concordance (OR=4.9, 95%CI=1.8-13.5, p=0.002) were associated with a good postoperative seizure outcome.</p> <p><strong>Conclusions</strong>: Small retrospective cohort studies are inherently prone to bias, some of which are overcome using individual participant data. The best evidence suggests 4 preoperative factors predictive of good seizure outcomes following resective epilepsy surgery. Given the low incidence of children with TSC undergoing epilepsy surgery, large long-term prospective multicenter observational studies are required to further evaluate the predictive factors identified in this review.</p>