Abstracts

We wished to study variables that influence outcome, in terms of seizure control, among patients with mesial temporal sclerosis who undergo surgery. We compared two surgical techniques. Some patients had a standard temporal lobectomy, and others had a selective amygdalo-hippocampectomy. In this retrospective study, we compared the outcomes of these surgical techniques with respect to seizure control., 61 patients with medically refractory epilepsy and mesial temporal sclerosis (seen on MRI and subsequent pathological examination) were evaluated. The two groups were very similar with regard to age, age at surgery, duration of epilepsy, handedness, risk factors such as febrile seizures, and side of resection. The number of anti-epileptic medications, before and after surgery, was the same in the two groups. 30 patients had a standard temporal lobectomy, and 31 had the more selective procedure. The choice of procedure was arbitrary. Follow-up information was collected at 6, 12, 18 and 24 months, and yearly thereafter. The mean duration of follow-up was 4.38 +/- 1.02 years. Outcome was assessed using the Engel classification. Patients were classified as Class I outcomes if they were seizure-free for the previous year. To simplify the statistics, patients in Classes II, III, and IV were pooled. Neuropsychological testing was done before surgery, and 6-12 months after surgery., Class I outcomes ranged from 63% to 96%. A trend towards a difference between the two surgical groups, with more Class I outcomes among those who had the standard procedure, was detected 4 years after surgery (89% vs. 67%), and a statistically significant difference was apparent 5 years after surgery (96% vs. 63%, p[lt] .01). However, if the data were analyzed with Class I defined as seizure-free since surgery, there was no difference between the two groups. Neuropsychological testing did not show a significant difference between the two groups before or after surgery., These data suggest that in patients with mesial temporal sclerosis a better outcome with respect to seizure control may be seen with a wider resection of the anterior-lateral temporal lobe. The difference, if there is one, depends on how a Class I outcome is defined. Roughly the same % of patients in both groups has post-operative seizures; but after several years, a higher % of those who had the wider resection has been seizure-free for at least a year. The clinical significance of this difference is uncertain.,