Abstracts

Over the years, the surgical approach to large hemispheric epileptic disorder has evolved toward more disconnection and less tissue removal, in an effort to limit morbidity and long-term complications. Peri-insular hemispherotomy is considered to have the maximal ratio of disconnection to excision among all procedures for hemispheric epilepsy. The goal of this study is to review the outcomes of children who have undergone this technique described in 1995. Charts of the nine patients who underwent hemispherotomy between 1993 and 2004 were reviewed. Pre-operative evaluation included video-EEG monitoring (7), MRI (9), and functional imaging (PET or SPECT) in six patients. Seizure outcome was recorded and related to the underlying pathology. The mean age at seizure onset was 1.6 years (range: 5 days-4.8 years). Six patients had complex partial seizures and three patients had infantile spasms followed by complex and simple partial seizures. The mean age at surgery was six years (range: 8 months-16 years). The mean follow-up after hemispherotomy was four years (1 month-11 years). The etiologies of epilepsy were vascular events (5), hemimegalencephalies (2), cortical dysplasia (1) and Rasmussen[apos]s syndrome (1). At last follow-up, eight (89%) patients were seizure free and one (11%) patient with hemimegalencephaly had a more than 75% reduction of seizures. All patients had hemiparesis pre-operatively. After surgery, seven had a stable motor deficit, while one improved and one worsened. One patient had a post-operative neuropsychological evaluation and was found to have a stable global developmental delay. The surgeries were well tolerated: three patients experienced transitory fever, one patient had a hemorrhage due to blood dyscrasia and there was no fatality. Peri-insular hemispherotomy is a valuable and well tolerated procedure for controlling seizures in children with intractable hemispheric epileptic disorders.