Abstracts

Rationale: Postsurgical outcome studies of patients with mesial temporal lobe epilepsy (MTLE) showed considerable amount of seizure recurrence in a long-term follow-up. Thus identification of predictive factors of long-term surgical outcome is important and useful to improve surgical outcome of MTLE. Methods: We enrolled 315 consecutive MTLE patients who had at least 2 years of postsurgical follow-up (ranged 2 to 17 years). Clinical characteristics and results of diagnostic tests were included as prognostic factors. Univariate and multiple logistic regression models were used to identify presurgical, surgical, and postsurgical factors that are independently predictive of the long-term outcome of our patients. And Kaplan-Meier survival curves were applied to define long-term seizure outcome. Results: Two conditions were significantly associated with poor seizure outcome at the last follow-up according to univariate analyses: the presence of cortical dysplasia in lateral temporal lobe as not detected on MRI (p=0.032) and the seizure recurrence during first postoperative year (p<0.001). Multivariate logistic regression analysis revealed the independent factors for prediction of unfavorable seizure outcome: seizure recurrence within first postoperative year (p<0.001), and existence of cortical dysplasia in lateral temporal lobe that was confirmed by histopathology (p=0.021). Conclusions: The absence of cortical dysplasia in lateral temporal lobe was an independent prognostic factor for favorable surgical outcome in our study. We also observed that the absence of seizure recurrence within first postoperative year was the predictor for good surgical outcome.