Refractory seizures secondary to radiation-induced focal cortical dysplasia/neuronal gigantism: illustrative case

BACKGROUND: Focal cortical dysplasia is a structural cause of drug-resistant epilepsy commonly identified in childhood. In rare cases, radiation-induced injury has led to radiation-induced cortical dysplasia, also known as “focal neuronal gigantism.” OBSERVATIONS: The authors present a 53-year-old woman with recurrent status epilepticus events after she had radiation therapy and surgery for a left frontal meningioma several years prior. Imaging revealed findings consistent with radiation necrosis and possible recurrence. The patient’s status epilepticus events required escalating therapies to manage. Scalp electroencephalography indicated that the seizure’s origin was in the left hemisphere. A craniotomy was performed to remove the left frontal lesion, and histopathology was consistent with radiation-induced focal cortical dysplasia/neuronal gigantism. The patient’s seizures ceased following the surgery, and she remains on maintenance antiseizure medications. LESSONS: Radiation-induced focal cortical dysplasia/neuronal gigantism is an incredibly rare complication of therapy. However, it warrants consideration in the context of radiation necrosis and intractable epilepsy.