Annals of Neurology

Comparative Effectiveness of Stereo-EEG versus Subdural Grids in Epilepsy Surgery

4 October, 2021

Lara Jehi MD, Marcia Morita-Sherman MD, Thomas E. Love PhD, Fabrice Bartolomei MD, William Bingaman MD, Kees Braun MD, Robyn Busch PhD, John Duncan FRCP, Walter J. Hader MD, Guoming Luan MD, John D. Rolston MD, Stephan Schuele MD, Laura Tassi MD, Sumeet Vadera MD, Shehryar Sheikh MD MPH, Imad Najm MD, Amir Arain MD, Justin Bingaman, Beate Diehl MD, Jane de Tisi BA, Matea Rados MD, Pieter Van Eijsden MD, Sandra Wahby MSc, Xiongfei Wang MD, Samuel Wiebe MD

Annals of Neurology 30 September 2021 Accepted Author Manuscript. DOI: 10.1002/ana.26238


To compare the outcomes of subdural electrode (SDE) implantations versus stereo-electroencephalography (SEEG), the two predominant methods of intracranial EEG (iEEG) performed in difficult to localize drug-resistant focal epilepsy.


The Surgical Therapies Commission of the International League Against Epilepsy created an international registry of iEEG patients implanted between 2005-2019 with ≥ 1 year follow-up. We used propensity score matching to control exposure selection bias and generate comparable cohorts. Study endpoints: 1) likelihood of resection after iEEG; 2) seizure-freedom at last follow-up; and 3) complications (composite of either post-operative infection, symptomatic intracranial hemorrhage, or permanent neurologic deficit).


Ten study sites from seven countries and three continents contributed 2,012 patients, including 1,468 (73%) eligible for analysis (526 SDE, 942 SEEG) of whom 988 (67%) underwent subsequent resection. Propensity score matching improved covariate balance between exposure groups for all analyses. Propensity-matched patients who underwent SDE had higher odds of subsequent resective surgery (odds ratio OR = 1.4, 95% CI 1.05 – 1.84), and higher odds of complications (OR=2.24, 95% CI 1.34-3.74; unadjusted: 9.6% after SDE vs. 3.3% after SEEG). Odds of seizure-freedom in propensity-matched resected patients were 1.66 times higher (95% CI 1.21, 2.26) for SEEG compared to SDE (unadjusted: 55% seizure-free after SEEG-guided resections vs. 41% after SDE)


Compared to SEEG, SDE evaluations are more likely to lead to brain surgery in patients with drug-resistant epilepsy, but have more surgical complications and lower probability of seizure-freedom. This comparative-effectiveness study provides the highest feasible evidence level to guide decisions on iEEG.