Auras as a prognostic factor in anterior temporal lobe resections for mesial temporal sclerosis

BACKGROUND AND PURPOSE: Anterior temporal lobectomy for mesial temporal sclerosis (MTS) is a very effective measure for the control of seizures, and the probability of becoming seizure-free is approximately 70-90%. However, 30% of patients still experience seizures after surgery. An aura is a subjective ictal phenomenon that may precede an observable seizure. However, there are few studies on the prognostic factor aura although, being the initial symptoms of epileptic seizures, many types of auras have significant localizing or lateralizing value. This study hypothesized that the type of pre-operative aura may predict the post-surgical outcome in patients with medically refractory temporal lobe epilepsy due to MTS. METHODS: Of 1214 patients evaluated for surgery in the Epilepsy Center of Faculdade de Medicina de São Jose do Rio Preto (FAMERP), a tertiary Brazilian epilepsy center, 400 underwent anterior temporal lobectomy (ATL) for MTS. The number and type of auras were analyzed and compared with the Engel classification for outcome. RESULTS: Analyzing the patients by the type of aura, those who had extratemporal auras had the worst post-surgical result according to the Engel classification. Although mesial auras are apparently a good prognostic factor, patients without aura also had a worse prognosis. There were no differences between simple and multiple auras. To identify the most appropriate candidates for ATL, it is very important to consider the favorable prognostic factors for counseling patients in daily practice. CONCLUSIONS: Patients with symptoms and clinical signs that suggest extratemporal involvement may have unfavorable outcomes.