Hemispherectomy Outcome Prediction Scale: Development and validation of a seizure freedom prediction tool

Alexander G. Weil, Evan C. Lewis, George M. Ibrahim, Olivia Kola, Chi Hong Tseng, Xinkai Zhou, Kao Min Lin, Li Xin Cai, Qing Zhu Liu, Jiu Luan Lin, Wen Jing Zhou, Gary W. Mathern, Matthew D. Smyth, Brent R. O'Neill, Roy Dudley, John Ragheb, Sanjiv Bhatia, Daniel Delev, Georgia Ramantani, Josef ZentnerJeffrey Ojemann, Anthony C. Wang, Christian Dorfer, Martha Feucht, Thomas Czech, Robert J. Bollo, Galymzhan Issabekov, Hongwei Zhu, Mary Connelly, Paul Steinbok, Jian Guo Zhang, Kai Zhang, Eveline Teresa Hidalgo, Howard L. Weiner, Lily Wong-Kisiel, Samuel Lapalme-Remis, Manjari Tripathi, Poodipedi Sarat Chandra, Walter Hader, Feng Peng Wang, Yi Yao, Pierre Olivier Champagne, Qiang Guo, Shao Chun Li, Marcelo Budke, Maria Angeles Pérez-Jiménez, Christian Raftapoulos, Patrice Finet, Pauline Michel, Karl Schaller, Martin N. Stienen, Valentina Baro, Christian Cantillano Malone, Juan Pociecha, Noelia Chamorro, Valeria L. Muro, Marec von Lehe, Silvia Vieker, Chima Oluigbo, William D. Gaillard, Mashael Al Khateeb, Faisal Al Otaibi, Niklaus Krayenbühl, Jeffrey Bolton, Phillip L. Pearl, Aria Fallah

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Objective: To develop and validate a model to predict seizure freedom in children undergoing cerebral hemispheric surgery for the treatment of drug-resistant epilepsy. Methods: We analyzed 1267 hemispheric surgeries performed in pediatric participants across 32 centers and 12 countries to identify predictors of seizure freedom at 3 months after surgery. A multivariate logistic regression model was developed based on 70% of the dataset (training set) and validated on 30% of the dataset (validation set). Missing data were handled using multiple imputation techniques. Results: Overall, 817 of 1237 (66%) hemispheric surgeries led to seizure freedom (median follow-up = 24 months), and 1050 of 1237 (85%) were seizure-free at 12 months after surgery. A simple regression model containing age at seizure onset, presence of generalized seizure semiology, presence of contralateral 18-fluoro-2-deoxyglucose–positron emission tomography hypometabolism, etiologic substrate, and previous nonhemispheric resective surgery is predictive of seizure freedom (area under the curve =.72). A Hemispheric Surgery Outcome Prediction Scale (HOPS) score was devised that can be used to predict seizure freedom. Significance: Children most likely to benefit from hemispheric surgery can be selected and counseled through the implementation of a scale derived from a multiple regression model. Importantly, children who are unlikely to experience seizure control can be spared from the complications and deficits associated with this surgery. The HOPS score is likely to help physicians in clinical decision-making.

Original languageEnglish (US)
Pages (from-to)1064-1073
Number of pages10
Issue number5
StatePublished - May 2021


  • hemispheric surgery
  • prognostication tool
  • seizure outcomes

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology


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