Palliative hemispherotomy in children with bilateral seizure onset

Abstract

Intractable epilepsy is a significant burden on families and on the cognitive development and quality of life (QOL) of patients. Periinsular hemispherotomy (PIH) for medically intractable epilepsy can benefit patients who qualify for this procedure. The ideal hemispherotomy candidate has ipsilateral ictal and interictal epileptiform activity, unilateral MR imaging abnormalities, contralateral hemiplegia, and a normal contralateral hemisphere. However, certain patients present with a mixed picture of bilateral electroencephalography (EEG) findings and severe intractable epilepsy, prompting consideration of a more aggressive treatment approach. This report introduces the possibility of surgery for patients who normally would not meet criteria for this treatment modality. In this retrospective chart review, the authors report on 7 patients with bilateral seizure onset noted on routine or video-EEG monitoring. A QOL phone questionnaire, based on the Quality of Life in Childhood Epilepsy tool, was administered to a parent. The authors reviewed each patient's chart for surgical complications, changes in examination, QOL, limited neuropsychological outcomes, and seizure outcomes. They also investigated each chart for MR imaging and EEG findings as well as the patient's epilepsy clinic notes for seizure semiology and frequency. All patients enjoyed a decrease in seizure frequency and a subjective increase in QOL after PIH. Five patients (71%) achieved Engel Class I or II seizure control. The mean follow-up was 3.64 years (2-5.3 years). One patient is now off all antiseizure medication. No patient had a decrement in Full Scale IQ on postsurgical testing, and 2 (28.5%) of 7 individuals had increased adaptive and social functioning. Postsurgical examination changes included hemiplegia and homonymous hemianopia. Hemispherotomy in patients with intractable epilepsy is generally reserved for individuals with unilateral epileptiform abnormalities or lesions on MR imaging. Seven patients in this study benefited from surgery despite bilateral seizure onset with improvement in seizure control and overall QOL. Thus, bilateral ictal onset does not necessarily preclude consideration for hemispherotomy in selected patients with severe medically refractory epilepsy.