Paediatric epilepsy surgery in the posterior cortex: a study of 62 cases

Past surgical series have emphasized the diagnostic complexity of posterior cortex epilepsy (PCE). Available data are sparse, especially in children, and most published series report a high number of surgical failures and post-operative neurological deficits. In this article, we present a paediatric cohort of 62 children who underwent surgery for pharmaco-resistant PCE before the age of 16 years with a mean postoperative follow-up of 6.94 years (range: 2-16). Mean age at epilepsy onset was 3.2 years and 28 children (45%) had onset before 1 year of age. The mean age at surgerywas 7.9 years (range: 1-16). Daily seizureswere present in 63% of children. MRIwas positive in 58 cases (93.5%) and invasive stereo-EEG was judged mandatory in 24/62 (39%) of patients. Surgery was confined to the parietal lobe in 11 children, the occipital lobe in 8, the occipito-parietal region in four, the occipito-temporal region in 18, and involved both the temporal and parietal lobes in the remaining 21. Following surgery, 53 subjects (85.5%) remained seizure-free and among those who underwent a SEEG procedure,75¬hievedseizure freedom. Focal cortical dysplasia was the most frequent histopathological diagnosis (50%), followed by tumoural (24%) and gliotic lesions (14.5%). An older age at epilepsy onset, the presence of a rather restricted epileptogenic area, and a complete resection of the epileptogenic zone were predictive of a favourable surgical outcome.These results demonstrate that a good surgical outcome is possible in children with pharmaco-resistant PCE. Accurate analysis of the chronology of ictal semiology and electrophysiological features, viewed in the context of the complete electroclinical pattern, provides a topographical orientation for PCE and, together with the presence of a lesion detectable on imaging, may improve the rate of surgical success of PCE at paediatric age.