Corpus callosotomy for children suffering from intractable focal epilepsy presenting a non-laterialized EEG and unilateral lesion

Objective: It is known that epilepsy surgery is a successful treatment even for children in their 1 st year of life who suffer from intractable focal epilepsy. Age dependent bilateral or even generalized EEG-findings and semiology may complicate the electro-clinical-anatomical correlation. Due to frequent seizures with encephalopathic course surgery is considered early on; therefore, rapid lateralization and localization of the epileptogenic zone is necessary. In 5 children with either suspected or actual unilateral epileptogenic lesion and non-lateralized interictal and ictal epileptiform discharges we performed a corpus callosotomy (CC) to lateralize the epilepsy. Methods: Out of 311patients who underwent epilepsy surgery between 09/1998 and 11/2010at the Epilepsy Center for Children and Adolescents, Schoen Klinik Vogtareuth, retrospective data of 5 patients in which CC was performed are presented. All patients underwent video-EEG long-term monitoring at least once plus high resolution MRI. Presurgical intensive diagnostic work up ruled out etiologies other than focal epilepsy caused by a lesion. Results: 5 patients had CC (f:1; m:4). All were severely retarded mentally. Etiology: Malformation of cortical development in 3, polymicrogyria in 2 patients. Average age at onset of epilepsy: 0,37 y, at surgery: 1,8 y, postoperative follow up: 12 months. Lateralization and localization of the epilepsy was possible In 2 patients after CC: One of the two underwent temporo-parieto-occipital resection, the other underwent hemispherotomy. Seizure outcome: After CC: Seizure-free: None; after the 2 nd surgery: Seizure-free: 1, >50% seizure reduction: 1 Conclusion: CC was helpful in 2 patients to lateralize the epilepsy in accordance with the side of the lesion and in order to find a decision regarding 2 nd surgery, which then led to an improvement of epilepsy. In 2 of the remaining 3 patients seizure frequency was reduced and interaction improved. CC can be helpful in the diagnostic work-up of infantile unilateral lesional epilepsy.