Abstracts

Rationale: : About 20-40% of patients with epilepsy have pharmacoresistant epilepsy. The benefit of surgery in drug resistant epilepsy has been demonstrated at various sites globally. This along with numerous recent technological advances in diagnostic and therapeutic modalities has resulted in increased number of patients considered for surgical intervention. We present the seizure outcome and prognostic factors after epilepsy surgery. Methods: We performed a retrospective review of all patients that underwent epilepsy surgery at University of Kentucky between January 2011 to November 2017 and identified 92 patients. We reviewed patient characteristics including gender, age, age at onset of seizures, age at surgery, family history of epilepsy, types and frequency of seizures, presence of status epilepticus, number of antiepileptics used, EEG findings, imaging findings, use of invasive monitoring, type of surgery, pathology, postoperative inpatient stay, postoperative complications, use of VNS and presence of psychiatric comorbidities to determine if they could predict seizure outcome. We report seizure outcomes using Engel classification. Results: We identified a cohort of 92 patients. 8 patients were lost to follow up and 2 patients were not deemed candidate for surgery after depth electrode placement. 49% were males and 51% were females. Mean age of seizure onset was 15 years and mean age at surgery was 32 years. Delay between onset and time to surgery was 17 years. 44% patients had temporal lobectomy, 21% patients had extra-temporal lobectomy, 13.5% patients had lesionectomy, 13.5% patients had corpus callosotomy and 8% patients had responsive neurostimulation. 9% patients had status epilepticus prior to surgery out of which 5% patients had status epilepticus within a year prior to surgery. 1% patient had status epilepticus after surgery which was secondary to not taking antiepileptics for 1 week. Histopathological analysis was performed on 80% of patients. 10% patients had cortical dysplasia, 11% had hippocampal sclerosis, 21% had tumor, 30 % had other focal abnormalities and 28% were unremarkable. 56% patients achieved surgical freedom described as Engel Class 1. 16 % patients demonstrated good surgical outcome with Engel Class 2. 28% patients were categorized as having poor surgical outcome of Class 3 and Class 4. Seizure freedom was achieved in 69% of patients with temporal lobectomy, 45% with extra-temporal lobectomy, 46% with lesionectomy, 7% with corpus callosotomy and 37% with responsive neurostimulation. Patients with 1-4 focal seizures with altered awareness had statistically significant improvement in seizure outcome [Figure 1]. Patients with generalized seizures also had significant improvement in seizures [Figure 1]. In our study, 14 patients had post-operative complications of which 12 resolved. Permanent complication rate was 1.82%. 1 patient developed quadrantanopia and 1 patient developed supplemental area syndrome. Conclusions: In this study, epilepsy surgery was associated with seizure freedom or significant improvement in seizure control in seventy-two percent of patients with pharmacoresistant epilepsy. Lower frequency of focal seizures with alteration of awareness was favorable prognostic factors for seizure freedom Funding: None