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Authors: Aria Fallah, MD, FAANS; Alexander Weil, MD; Evan Lewis, MD; George Ibrahim, MD, PhD; Olivia Kola, BS; Chi-Hong Tseng, PhD; Xinkai Zhou, MS (Los Angeles, CA)


To develop and validate a model to predict seizure freedom in children undergoing cerebral hemispheric surgery for the treatment of drug-resistant epilepsy.


We analyzed 1267 hemispheric surgeries performed in pediatric patients across 30 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 was handled using multiple imputation techniques.


Overall, 817/1267 (64%) hemispherectomies led to seizure freedom.  The regression model containing age at seizure onset, presence of generalized seizure semiology, etiologic substrate and  previous non-hemispheric resective surgery were predictive of seizure freedom (Training set AUC 0.68, Testing set AUC 0.61).   A simplified Hemispheric Surgery Outcome Prediction Scale (HOPS) score was devised and validated based on these results that can be used to predict seizure freedom.


Children most likely to benefit from hemispheric surgery can now be appropriately selected and counselled through the implementation of an easy-to-use scale.  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.