Refractory Epilepsy as a Late Effect of Chemoradiation in Childhood Cancer: A Case Series

Seizures are a common complication of both primary central nervous system (CNS) tumors and other oncologic processes with CNS involvement. They occur most frequently during induction or consolidation therapy, but there is a growing body of evidence that they can also develop later in life. Refractory epilepsy can develop as a late complication for survivors of pediatric cancer with CNS involvement who undergo chemoradiation therapy.

We report three patients who presented with atypical nonconvulsive seizures (behavioral arrest, falls, nonsensical speech) up to 14 years after cancer diagnosis. All underwent whole-brain radiation in addition to chemotherapy. None had a prior epilepsy diagnosis or known prior seizures. One patient suddenly passed away of unclear causes five months after diagnosis, and the other two continued to have EEG findings consistent with cerebral dysfunction and epileptogenicity years after diagnosis.

We hypothesize that the development of refractory epilepsy may be a late effect of radiation treatment. Given the high morbidity and mortality associated with epilepsy, early identification is crucial to improve outcomes and quality of life for this vulnerable population. This is especially true for patients with medication-refractory epilepsy as there is an increasing breadth of effective surgical options.