Abstracts

Rationale. It is well known that bilateral temporal lobectomy causes severe amnesia; on the other hand, vagus nerve stimulation does not offer important seizure control1 (Engel class IV)2. As a result of this, patients who have drug resistant mesial temporal lobe epilepsy with bilateral foci usually are not offered surgery. Hippocampal stimulation has proved to be a safe and efficient procedure for patients who are not suitable candidates for temporal lobectomy, specially in those without hippocampal sclerosis3,4,5. Methods. We present a retrospective review of patients who underwent surgery for treatment of temporal lobe epilepsy. Five of them had bilateral foci. All patients went through a presurgical evaluation process that comprised clinical evaluation, surface EEG, neuropsychological evaluation, MRI, and depth electrode continuous video EEG. Electrodes were placed through occipital burr-holes. The first two patients had a first surgical procedure for electrode implantation and a second surgical procedure for implantation of extension and pulse generator. For the rest of the patients implantation was made in a single surgical procedure. Results. From june 1999 to july 2008 five patients with mesial temporal lobe epilepsy with bilateral foci have been surgically treated at our Epilepsy Surgery Clinic. The first four patients underwent bilateral hippocampal stimulation; one of them, patient 2, had left hippocampal sclerosis. Patient 5 had right hippocampal sclerosis, she underwent right temporal lobectomy and left hippocampal stimulation. By 18 months follow-up all patients had seizure reduction, with patient 2 in Engel class II and the rest of patients, in Engel class I. Conclusions. Patients with drug resistant mesial temporal lobe epilepsy who have bilateral foci can be offered surgical treatment. Hippocampal stimulation techniques and its combination with conventional ablative procedures have accomplished seizure reduction with no cognitive sequelae.