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

Area of Science:

• Pediatric Neurosurgery
• Epilepsy Surgery
• Clinical Prediction Modeling

Background:

• Drug-resistant epilepsy in children often necessitates surgical intervention.
• Cerebral hemispheric surgery is a treatment option for severe pediatric epilepsy.
• Predicting seizure freedom post-surgery is crucial for patient selection and management.

Purpose of the Study:

• To develop and validate a predictive model for seizure freedom in pediatric patients undergoing cerebral hemispheric surgery.
• To identify key predictors of successful surgical outcomes in this population.
• To create a practical tool for clinical decision-making.

Main Methods:

• Analysis of 1267 hemispheric surgeries across 32 centers and 12 countries.
• Development of a multivariate logistic regression model using a training set (70%) and validation set (30%).
• Inclusion of predictors such as age at seizure onset, seizure semiology, PET hypometabolism, etiology, and prior surgeries; multiple imputation for missing data.

Main Results:

• Overall seizure freedom achieved in 66% of patients at 3 months and 85% at 12 months.
• A predictive model incorporating age, generalized seizure semiology, contralateral PET hypometabolism, etiology, and prior surgery demonstrated predictive value (AUC = 0.72).
• A Hemispheric Surgery Outcome Prediction Scale (HOPS) was developed.

Conclusions:

• The HOPS score can aid in selecting pediatric candidates most likely to benefit from hemispheric epilepsy surgery.
• Implementation of the HOPS score may help avoid surgical complications in children unlikely to achieve seizure control.
• The HOPS score supports clinical decision-making for pediatric epilepsy surgery.