Abstracts

Rationale: parietal lobe epilepsies are the third most prevalent focal epilepsies. As it poses a difficult clinical and neurophysiological characterization, represents a challenge to the localization of the epileptogenic zone. The objective of this work is to evaluate clinical and neurophysiologic characteristics and long term surgical outcomes of parietal lobe patients followed at the Epilepsy Surgery Center of Clinical Hospital, Ribeirão Preto Medical School, University of São Paulo, Brazil.Methods: this is a retrospective cohort study from a single tertiary center. Data were obtained from medical records of pharmacoresistant patients evaluated clinically and with video-EEG monitoring between june, 1994, to december, 2014. Considering inclusion and exclusion criteria, we analysed 46 eligible patients that were submitted to a presurgical evaluation and diagnosed as having parietal lobe epilepsy. Among these, 19 were not submitted to a surgical treatment and 27 were submitted to a surgical treatment. Epidemiological data such as clinical characteristics, complementary exams results and post treatment outcomes were obtained.Results: the mean age (SD) of epilepsy onset was 7,5 (6,8), of the first video-EEG in our institution was made was 24,8 (12,6). Among presurgical parameters, only a high frequency of seziures during the video-EEG correlated with a higher chance to epilepsy surgery treatment occur. Within patients submitted to the epileptic surgical treatment, at the first postoperative year, 55,6% were classified as having Engel 1, 11,1% as having Engel 2 and 33,3% as Engel 3 or 4. On subsequent years, some patients were reclassified if a sustainable change in seizure frequency occurs. The Kaplan-Meier survival curve showed that surgical patients were more prone to remain in Engel 1 classification more time than non surgical patients (p=0,01). The main limitations of our study are a small number of patients selected and a bias of selection.Conclusions: in agreement with previous data shown from other studies, in this work we corroborated that parietal lobe epilepsy ensures a high challenge for clinical and neurophysiological characterization, thus, in epileptogenic zone localization. Besides this, parietal lobo epilepsy surgery for pharmacoresistant patients is a safe and effective treatment. The benefit of epilepsy surgery in our study prevail on the short and long period of time.