Award: American Academy of Pediatrics Award

Authors: Omeed Modiri; Diana Babayan, MPH; Srinivas Chivukula, MD; George Ibrahim, MD, PhD, FRCSC; Alexander Weil, MD, FRCSC; Albert Tu, MD, FRCSC; Joyce Wu, MD; Aria Fallah, MD, MSc, FRCSC (New York, NY)

Introduction: Tuberous Sclerosis complex is a rare genetic disorder affecting multiple organ systems, and causes epilepsy in most patients. TSC is attributed to a mutation in one of two different genes, TSC1 or TSC2. While differences in disease phenotypebased on the gene mutation has been analyzed in prior studies, little is known about the differences in treatment outcome. The aim of this study was to compare the efficacy of respective epilepsy surgery and vagus nerve stimulation (VNS) between patients with a TSC1 or TSC2 mutation. Methods: A retrospective study of TSC patients was conducted using the TSC Natural History Database. Data was extracted regarding patient demographics, mutation type, epilepsy treatment, and outcome. The review of data was focused on patients treated with surgical resection and VNS. The seizure outcomes were then compared between patients with a mutation in TSC1 or TSC2. Results: A total of 42 patients with a TSC1 mutation and 145 patients with a TSC2 mutation were identified. We found that children with TSC2 mutation were diagnosed at an earlier age than children with a TSC1 mutation (p<.001), and infantile spasms were more common in TSC2 patients(p<.001). Among patients undergoing resective surgery, those with a TSC2 mutation may have inferior outcomes than those with a TSC1 mutation. A total of 66% of TSC1 patients had their epilepsy controlled with surgical resection, compared to 47% of TSC2 patients (p=0.09). In patients with VNS, the treatment outcomes between both groups were similar. Conclusion: Patients with a TSC2 mutation are more likely to experience infantile spasms and be diagnosed earlier than TSC1 patients, and may respond less favorably to resective epilepsy surgery. Due to the small sample size, we were unable to determine which one or combinations of these characteristics is most important for surgical prognosis. Further studies are needed to confirm these findings.