Abstracts

Rationale: Epilepsy surgery (ES) is one of the major treatments of refractory partial epilepsy. It was proven to be effective in temporal lobe and extra-temporal epilepsies with or without a clear epileptogenic lesion. The majority of the ES studies have involved adult patients with no major co-morbidities. Fewer studies have been done in elderly patients who underwent ES. Most of these studies included patients older than 50 years of age, and evaluated short term outcome, and were limited to temporal lobe epilepsies. In this study, we retrospectively analyzed different outcome measures in all patients older than 60 years of age who underwent ES in our institution. Methods: We reviewed the Vanderbilt adult ES database between 1/1/2000 and 12/31/2010 and identified all elderly patients who underwent ES. Out of about 600 patients, 24 patients met our inclusion criteria. We recorded and analyzed the following variables: gender, age at epilepsy onset, seizure risk factors, epilepsy duration, pre-ES seizure frequency, count of anti-epileptic drugs (AEDs) trials and at initial evaluation. We included in our analysis structural (MRI) and functional imaging (PET scans), final epileptogenic focus localization and age at ES. We then included type of ES, complications, duration of post-ES follow up and Engel classification for seizure control. Wilcoxon rank sum test was conducted for continuous variables of interest and chi square or Fisher's exact test was used for categorical variables of interest.Results: Twenty four patients were analyzed, with a median age at ES of 62 years. Half of the patients were females, with a median age of epilepsy onset of 28 years. Median epilepsy duration was 36 years. The median time of follow-up after ES was 13.5 months. 41% of patients had either a vascular or a traumatic process as risk factors. 21% of patients had failed up to seven AEDs in their lifetime. 79% of patients were on more than two AEDs at initial evaluation. Seizure localization was either right or left temporal in 88 % of patients. 83% had MRI abnormalities while 54 % had abnormal PET scans. Selective amygdalo-hippocampectomy was the most common type of surgery performed in 54 % of patients. Persistent postoperative complications were seen in only 4 % of patients. 50 % of patients had Engel class 1 outcome at 2 years. 75% of patients were seizure-free with a median post-ES follow-up of 13.5 months. Higher rate of seizure freedom tended to occur in patients with older age at onset, shorter epilepsy duration, and older age at ES Conclusions: In the elderly, ES results in excellent seizure-free outcomes with low risk of complications. ES should be strongly considered in older patients with drug resistant partial epilepsy.