Abstracts

Predictive Factors for Seizure Freedom After Epilepsy Surgery for Pediatric Low-grade Tumors and Focal Cortical Dysplasia

Abstract number : 3.326
Submission category : 9. Surgery / 9B. Pediatrics
Year : 2022
Submission ID : 2204101
Source : www.aesnet.org
Presentation date : 12/5/2022 12:00:00 PM
Published date : Nov 22, 2022, 05:23 AM

Authors :
Alena Hornak, BA – Boston Children's Hospital; Alyssa Ailion, Ph.D. – Attending Neuropsychologist, Neurology, Boston Children's Hospital; Melissa Tsuboyama, MD – Pediatric Neurologist, Neurology, Boston Children's Hospital; Phillip Pearl, MD – Director of Epilepsy and Clinical Neurophysiology, Neurology, Boston Children's Hospital; Song Dam, BS – Research Assistant, Neurology, Boston Children's Hospital; Trey Moore, BS – Research Assistant, Neurology, Boston Children's Hospital; Brigitte Wilson, BS – Research Assistant, Neurology, Boston Children's Hospital; Jeffery Bolton, MD – Pediatric Neurologist, Neurology, Boston Children's Hospital

Rationale: Epilepsy may be drug-resistant in up to a third of patients requiring alternative treatments, such as surgery. Among refractory epilepsy, tumor and focal cortical dysplasia (FCD) are common etiologies. Surgical treatment of tumor related epilepsy has one of the highest rates of seizure freedom in epilepsy surgery, whereas FCD has some of the lowest. Many factors may contribute to poorer seizure outcomes seen in FCD patients, such as subtle or non-lesional MRIs, multilobed epilepsy and longer disease duration. This study will investigate pre-operative characteristics that explain the difference in post-surgical seizure outcomes in patients with FCD and tumor. This research is important because it may help inform pre-surgical practices.

Methods: We completed a retrospective review of epilepsy surgery patients with tumor (n=26) or FCD (n=47) based on pathology reports at BCH between 2003-2020. FCD type 2 and low-grade gliomas were the most common pathologies (65% and 46%, respectively). All patients had a medical follow-up at least six months after surgery (FCD M=2.3 years; Tumor M=3.4 years).

Results: Patients with FCD had an earlier age of onset (t=-3.27, p=.01) and longer epilepsy duration (t=3.61, p< .01) than patients with tumors. There was no difference between FCD and tumor post-surgical seizure freedom (72 vs. 73%, respectively). An interaction between lesion location and etiology indicated that temporal lesions were more likely to result in seizure freedom for FCD; however, tumor patients had a high rate of seizure freedom regardless of lesion location (B=-3.08, p< .05). Additionally, an interaction between lesion location and resection status (i.e., complete/incomplete) indicated that patients with an extratemporal lesion had a greater chance of seizure freedom with complete resection, whereas patients with temporal lesions had a high rate of seizure freedom regardless of resection status (B=-3.01, p< .05). In a subset of the sample (FCD, n = 40; tumor, n= 13), SPECT and PET concordance were predictive of seizure freedom, with SPECT predictive for all patients and PET predictive for FCD.
Surgery