Abstracts

Many factors are considered in selecting epilepsy surgical candidates. Etiology and region of resection are often thought to be influential variables in predicting a successful outcome. We analyzed all pediatric patients who underwent initial resective surgery at Minnesota Epilepsy Group, PA from Jan 2000-Dec 2002. Diagnostic variables including etiology and region of resection were reviewed. Etiology was described as symptomatic or idiopathic. Etiology was also specifically categorized into congenital, genetic, infectious, neoplastic, traumatic, vascular, extra-temporal encephalomalacia, mesial temporal sclerosis, undetermined, as well as an [ldquo]other recognized pathology[rdquo] group. Regions of resection were organized into temporal versus extra-temporal. Extra-temporal was grouped into frontal, parietal, and multilobar resection. Subjects were scored at follow-up at 12- and 24-months by Engel classification. Outcomes of Engel I and II classes were considered beneficial. Statistical method utilized Fisher[apos]s Exact Test. Forty-six consecutive subjects were identified and reviewed; 23 (50%) underwent temporal lobe-only resection; extra-temporal resections included 10 (22%) frontal, 1 (2%) parietal, and 12 (26%) multi-lobe. 41/46 (90%) of subjects had follow-up data: 23/41 (56%) were seizure free at 12-months, and 19/33 (58%) were seizure free at 24-months. Of those patients with follow-up data at 12-months, 13/21 (62%) subjects with temporal lobe-only resection were seizure free compared to 10/21 (48%) with extra-temporal surgery. This was not a statistically significant difference (p[lt]0.268). However, temporal lobe surgery was statistically more successful achieving a beneficial outcome of Engel I-II in 17/21 (81%) subjects compared to 11/21 (52%) of the extra-temporal group (p=0.05). This trend continued to be significant at 24-months (p[lt]0.046). Subjects with symptomatic etiology achieved similar seizure freedom at 12-months in 21/35 (60%) compared to 2/7 (29%) subjects with probably symptomatic etiology (p[lt]0.134). Etiology did influence beneficial outcome (symptomatic 26/35: 74%; probably symptomatic 2/7: 29%) at 12-months (p[lt]0.031) but not at 24-months (symptomatic 23/30: 77%; probably symptomatic 1/3: 33%) (p[lt]0.174). This is may be influenced by low numbers within the probably symptomatic group. Pediatric patients with temporal lobe resections are more likely to achieve a beneficial outcome compared to extra-temporal resections, despite having similar seizure free rates. The major difference between these groups is Engel class II. Patients with symptomatic etiology achieved beneficial outcomes more often than those with probably symptomatic etiology at 12-months, but this trend failed after 24-months.