Functional surgery in pediatric drug-resistant posterior cortex epilepsy: Electro-clinical findings, cognitive and...

Epilepsies originated from the occipital, parietal and/or the posterior edge of the temporal lobe are grouped together into posterior cortex epilepsy (PCE). Our objective was firstly to describe electro-clinical and imaging findings in the presurgical evaluation of children with PCE, and secondly to identify potential factors associated with surgical and cognitive outcomes.

From the total of patients referred to the Epilepsy Monitoring Unit of 'Hospital Universitario Niño Jesús' from 2003 to 2016, 55 had drug-resistant PCE. Different variables obtained from the multimodal presurgical work-up were analyzed among patients achieving seizure freedom after surgery (ILAE class 1) and patients with persistent seizures. Categorical variables were compared with Fisheŕs exact test and numeric variables with t-Student for independent samples, and multiple logistic regression were used to analyze predictive values.

Median duration of epilepsy until surgery was 5 years [3-10 years]. Fifty patients showed lesions in the MRI, and 62.5% had concordant MRI-PET corregistration. 37 (67%) patients were operated (lesionectomy in 21 subjects, tailored resection based on intracranial studies in 16), and 23 (62,2%) reached ILAE class 1, with a mean follow-up period of 3.51 [1-12] years. A lower number of basal seizures and antiepileptic drugs, a well-defined lesion on the MRI, an epileptogenic zone (EZ) restricted to the posterior quadrant and the normalization of postsurgical EEGs were associated with seizure freedom (p<0.05). Additionally, 65% of patients had a long-term improvement of cognitive performances.

Epilepsy surgery should be considered in children with drug-resistant PCE, especially in those with a restricted EZ.