Abstracts

Rationale: Surgical therapy may improve the quality of life of patients with medically intractable partial epilepsy by reducing or eliminating seizures and enabling reduction of the dosages or number of antiepileptic drug (AED) therapies administered, thereby improving adverse effects. We describe the comparative number of pre-operative and post-operative antiepileptic drug therapies administered in patients who received epilepsy surgery. Methods: We retrospectively reviewed our epilepsy surgery database, and included patients with resective operations between 1993-2005. All patients received a standardized preoperative series of investigations, including a seizure protocol magnetic resonance image (MRI) of the brain, electroencephalography (EEG) and inpatient prolonged video-EEG monitoring, positron emission tomography (PET) scanning, and neuropsychological and sodium amytal (Wada) testing. Selected patients also received ictal single photon emission computed tomography (SPECT). Patients subsequently received either anterior temporal lobectomy, extratemporal resection, or multiple subpial transections after localization of the surgical epileptic focus and determination of functional anatomy. The number of AEDs utilized just before surgery and currently were analyzed. We attempted to contact all patients with greater than one year follow-up by a mailed survey, or if they failed to respond, by telephone.Results: 175 patients underwent epilepsy surgery. 96 (54.9%) of these agreed to complete a seizure outcome survey, and of these, 92 had data regarding AED usage before and after surgery. The mean number of antiepileptic drugs each patient received pre-operatively was 2.16 (range 0-4), and postoperatively was 1.28 (range 0-4). Comparing the number of AEDs utilized before and after surgery, 54 patients (58.7%) had AED reduction, 31 (33.7%) had no change in AED number, and 7 (7.6%) had the number of AEDs increased. 70 patients (76%) received polytherapy with 2 or more AEDs pre-operatively, while 33 (36%) received polytherapy post-operatively. 15 (16%) were drug-free post-operatively, compared with 2 (2%) pre-operatively.Conclusions: The majority of patients who received epilepsy surgery enjoyed reduction of the number of AEDs received following surgery, particularly of AED polytherapy. A substantial minority of patients were able to discontinue medication after surgery. Epilepsy surgery is a drug-sparing non-pharmacologic therapy. Additional analysis of quality of life and adverse effects data will be informative in recognizing the impact of AED reduction following operative intervention.