Temporal lobe epilepsy surgery: outcome, complications, and late mortality rate in 215 patients

Abstract

Purpose: We studied the surgical outcome, complications, and the late mortality rate in a large group of patients with medically refractory temporal lobe epilepsy (TLE).

Methods: Two-hundred fifteen patients with TLE were treated surgically between 1984 and 1999 after a comprehensive presurgical evaluation. Patients were followed up at 6 weeks, 3-6 months, and yearly thereafter. In addition, questionnaires were sent on the anniversary of their surgery. Surgical outcome (Engel's classification), complication rate, and factors contributing to late mortality were analyzed. Standardized mortality ratios (SMRs) were calculated.

Results: There was no surgical mortality. Two (0.9%) had mild hemiparesis, one (0.4%) had a hemianopia, seven (3.2%) had transient cranial nerve palsies, and eight (3.7%) had transient postoperative language difficulties. One hundred forty-eight (69%) became seizure free, 43 (20%) had rare seizures, 14 (6.5%) had worthwhile seizure reduction, and 10 (4.6%) had no improvement (follow-up, 1-15 years). Three (2%) of 148 seizure-free patients died during follow-up, compared with eight (11.9%) of 67 not seizure-free patients. The mean duration of epilepsy before surgery for the surviving patients was 17.8 years, and for those patients who died, 25.9 years (p < 0.05). Six (5.7%) of 104 patients with right-sided resections died during follow-up, compared with five (4.5%) of 111 with left-sided resections.

Conclusions: Eighty-nine percent of patients became seizure free or had rare seizures, with low morbidity, and no surgical mortality. The late mortality occurred predominantly in patients with persistent seizures (SMR, 7.4). Those patients who died had a longer duration of epilepsy before surgery. In contrast, among those patients who became seizure free, the mortality rate was much lower, and similar to the general population of Indiana (SMR, 1.7).