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Derivation and initial validation of a surgical grading scale for the preliminary evaluation of adult patients with drug-resistant focal epilepsy. Epilepsia 2017 05;58(5):792-800



Pubmed ID




Scopus ID

2-s2.0-85017465061   22 Citations


OBJECTIVE: Presently, there is no simple method at initial presentation for identifying a patient's likelihood of progressing to surgery and a favorable outcome. The Epilepsy Surgery Grading Scale (ESGS) is a three-tier empirically derived mathematical scale with five categories: magnetic resonance imaging (MRI), electroencephalography (EEG), concordance (between MRI and EEG), semiology, and IQ designed to stratify patients with drug-resistant focal epilepsy based on their likelihood of proceeding to resective epilepsy surgery and achieving seizure freedom.

METHODS: In this cross-sectional study, we abstracted data from the charts of all patients admitted to the New York University Langone Medical Center (NYULMC) for presurgical evaluation or presented in surgical multidisciplinary conference (MDC) at the NYU Comprehensive Epilepsy Center (CEC) from 1/1/2007 to 7/31/2008 with focal epilepsy, who met minimal criteria for treatment resistance. We classified patients into ESGS Grade 1 (most favorable), Grade 2 (intermediate), and Grade 3 (least favorable candidates). Three cohorts were evaluated: all patients, patients presented in MDC, and patients who had resective surgery. The primary outcome measure was proceeding to surgery and seizure freedom.

RESULTS: Four hundred seven patients met eligibility criteria; 200 (49.1%) were presented in MDC and 113 (27.8%) underwent surgery. A significant difference was observed between Grades 1 and 3, Grades 1 and 2, and Grades 2 and 3 for all presurgical patients, and those presented in MDC, with Grade 1 patients having the highest likelihood of both having surgery and becoming seizure-free. There was no difference between Grades 1 and 2 among patients who had resective surgery.

SIGNIFICANCE: These results demonstrate that by systematically using basic information available during initial assessment, patients with drug-resistant epilepsy may be successfully stratified into clinically meaningful groups with varied prognosis. The ESGS may improve communication, facilitate decision making and early referral to a CEC, and allow patients and physicians to better manage expectations.

Author List

Dugan P, Carlson C, Jett?? N, Wiebe S, Bunch M, Kuzniecky R, French J


Chad Carlson MD Professor in the Neurology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Cohort Studies
Drug Resistant Epilepsy
Epilepsy, Partial, Motor
Likelihood Functions
Magnetic Resonance Imaging
Referral and Consultation
Risk Assessment
Temporal Lobe