Prognostic Factors in Anterior Temporal Lobectomy for Mesial Temporal Lobe Epilepsy: Multivariate Analysis

Background : In order to identify the prognostic factors of anterior temporal lobectomy (ATL) for mesial temporal lobe epilepsy (TLE), we performed multivariate analyses in patients with mesial TLE. Methods : One hundred eighty six patients with mesial TLE (112 men and 74 women; mean age 28.98.7 years) were included. The primary outcome variable was a the patient's status in the third postoperative year: seizure free (except aura), or not. Clinical, electroencephalographic, radiological, intracarotid amobarbital test, and pathologic data were considered. Clinical data included age at surgery, age at nonfebrile seizure onset, duration of epilepsy, sex, seizure frequency, secondary generalization, history of febrile seizure, and existence of aura. Results : One hundred fifty eight patients (84.9%) had remission of seizure. Univariate analysis found age at surgery (p=0.006) and MRI abnormality including hippocampal sclerosis ipsilateral to surgery (p=0.01) to be significant. Multivariate analyses using logistic regressions, the younger age at surgery (p=0.002) and MRI lateralization (p=0.02) were found to be the significant predictors for good surgical outcome. Conclusions : Age at surgery and hippocampal findings on MRI are independent prognostic factors for ATL in mesial TLE. These findings suggest that mesial TLE is a progressive disorder and surgical outcome is better when early ATL is performed, at least in medically intractable cases.