Authors :
Presenting Author: Alexandria Valdrighi, MD – Stanford
Brenda Porter, MD, PhD – Stanford
Ann Hyslop Segeren, MD – Stanford Medicine Children’s Health
Aditi Trivedi, MD – Stanford University
William Gallentine, MD – Stanford
Katherine Xiong, MD – Stanford
michaela Castello, MD,PhD – Stanford
Hyunmi Kim, MD, PhD, MPH, FAES – Stanford
Juliet Knowles, MD/PhD – Stanford University
Chris Lee-Messer, MD, PhD – Stanford
Emily Spelbrink, MD, PhD – Stanford
Fiona Baumer, MD – Stanford
H. Westley Phillips, MD – Stanford University School of Medicine
Vivek Buch, MD – Stanford University
Laura Prolo, MD – Stanford
Kelly Mahaney, MD – Stanford
Rationale:
Epilepsy surgery in patients with tuberous sclerosis complex (TSC) is associated with reduced seizure frequency and improved cognition, yet surgical utilization is low. Complex and dynamic epileptogenic networks and underdeveloped success predictors may contribute to gaps. We examined post-operative surgical outcomes and in those with recurrent seizures, determined if these were coming from adjacent tissue to the original resection or distant epileptic foci with prior interictals. Methods:
We retrospectively identified patients with TSC aged 0-18 at Stanford with surgery between 2011-2024. We reviewed medical records for number and type of surgeries, outcomes at last follow-up and age at first surgery. We assessed location of seizure recurrence (same, new) and if new foci had prior interictals. Results:
38 patients were included. Patient had between 1-5 surgeries (13 one surgery, 13 two, 5 three, 6 four, 1 five). Median age at first surgery was 3 years [1.25-7.75]. Median age at first surgery was similar between single 3 [2-5] and repeat 3[1-6] surgeries. A similar percent of those needing repeat surgeries underwent an initial resection (68%) vs. ablation (58%). Median follow-up time was 2.17 years [1.25-3.59]. Post-operative seizure freedom rates declined with subsequent surgeries (1: 58%, 2: 48%, 3: 42%, 4: 29%, 5: 0%). Most post-operative seizure recurrences were from nearby or adjacent seizure foci (58%;n=36). Recurrence from new epileptic foci was highest after the first surgery (44%;n=11). Most (69%;n=18) with new foci had prior interictals detected on preoperative EEGs from the eventual epileptogenic zone.
Conclusions:
Age at first surgery and surgery type were similar in single versus repeat surgeries signifying that other factors need to be examined for predicting outcomes. Most seizure recurrences were from a prior targeted source but, there was a high rate of recurrence from new foci with prior interictals. After resection of a primary seizure focus, other foci may develop increased epileptogenicity and become dominant seizure nidi. Connectivity metric analysis could assist surgical planning by identifying future epileptogenic tubers. Recurrence rates from new foci gradually decreased over time indicating that resistant epileptogenic sources likely contributed to subsequent surgeries. Additionally, it may suggest that targeting a few dominant seizure foci better disrupts epileptogenic networks to prevent kindling of new sources.
Funding: None