Longitudinal Seizure Outcome and Predictors After Hemispherectomy in 170 Children

In the December 5, 2012 issue of Neurology articles ahead of press, Drs. Moosa and colleagues from the Departments of Neurology, Neurosurgery, Section of Pediatric Epilepsy at the Cleveland Clinic present an important investigation looking at surgical results after completion of hemispherectomy operations in 170 children. Hemispherectomy is probably one of the most radical of epilepsy surgeries often not studied widely given the complexities of the procedure and the relatively small number of operations done around the world.. The Epilepsy Center Group at Cleveland Clinic reviewed its database of children who underwent the procedure between the years 1997 and 2009. One-hundred-eighty-six consecutive children were identified and various aspects of their case, including how they presented, the EEG, imaging studies and surgical data was collected and then the outcome of how these individuals did with regard to seizures were assessed via a questionnaire by contacting families from their medical records at their last follow-up visit.

Of 170 patients, there were no perioperative complications or deaths. The average follow-up period was 5.3 years. One-hundred-twelve ( 66% )were seizure free at followup. In 58 patients with seizure recurrence, eight had late remission and 16 had a greater than 90% seizure reduction. At last follow-up, 136 patients( 80%) were either seizure free or had major improvement. The estimated probability of seizure freedom after a hemispherectomy was 78% at six months; 76% at one year; 71% at two years; and 63% at five years. On multivariate analysis to pinpoint predictors of surgery success, bilateral PET abnormalities and acute postoperative seizures were those factors that independently predicted whether seizures were likely to recur. The authors concluded that the long-term seizure-free rates after hemispherectomy remain stable at 63% at five years and beyond.

This study helps to document the success rate of hemispherectomies. This procedure when performed in the right individual can be lifesaving. More data is needed to better identify the best clinical scenarios when this procedure can be done and its complication. Nevertheless, the study is important in furthering our understanding and knowledge of how individuals fare after this procedure.