Results of reoperation for failed epilepsy surgery.

A total of 37 patients who failed epilepsy surgery were evaluated with magnetic resonance imaging and long-term scalp electroencephalographic monitoring before reoperation. Repeat surgery involved focal resections after initial focal resections (30 cases) or stereotactic lesions (one case), or focal resections following anterior corpus callosotomy (six cases). Patients with initial focal resections followed by enlargement of the original operative site had the most successful outcome, especially those with complex partial seizures of temporal lobe origin. The most common cause for poor outcome of the original operation in patients with temporal lobe epilepsy was insufficient hippocampal resection. Patients who were most likely to benefit from reoperation were: 1) those with initially incompletely resected structural lesions; 2) those who were initially evaluated with invasive ictal monitoring; and 3) those who underwent further resection of the initial operative site rather than resection of a different cortical region.