Pearls & Oy-Sters: Tiny Frontal Lesion Presenting With Generalized Epilepsy

A 19-year-old woman presented with drug-refractory epilepsy since age 7 years. She had bilateral tonic seizures, generalized paroxysmal fast activity, and trains of anteriorly predominant <2.5 Hz generalized spike-wave discharges, but no intellectual disability. Structural MRI demonstrated a solitary 1 cm nodule of subcortical heterotopia in the right frontal pole that had been felt to be unrelated because of the "generalized" field of epileptiform discharges. A sEEG study targeting the nodule and adjacent frontal lobe demonstrated almost continuous epileptiform discharges from the nodule with more than 60 electrographic seizures arising broadly from the frontal electrodes. Radiofrequency thermocoagulation to the nodule resulted in more than 3 years of seizure freedom. This case demonstrates that highly focal lesions can produce a generalized electroclinical phenotype.