Abstracts

Selection of pediatric epilepsy surgical candidates requires analysis of many variables to identify patients likely to significantly benefit with minimal complication/s. This retrospective review will identify predictive trends between diagnostic variables and outcome. We analyzed patients who underwent initial resective surgery at Minnesota Epilepsy Group from Jan 2000-Dec 2001. Seizure semiology, ictal/interictal scalp EEGs, and MRIs were analyzed. Neuropsych testing, MRS, PET with glucose, alpha-methylo-L-tryptophan, flumazenil isotopes, and SPECT studies were reviewed if obtained in the evaluation. Diagnostic abnormalities were characterized by their lateralization/location in the frontal, temporal, parietal or occipital lobe. Findings were categorized by support, neutrality or conflict with region of resection. Supporting variables were located within the region of resection. Neutral findings were ipsilateral but not in the region of resection. Any diffuse or contralateral anbormality to the region of resection was defined as a conflicing variable. Diffuse cognitive dysfunction was excluded. Patients were scored at follow-up at 6-, 12-, 24-months by Engel classification, percent seizure reduction, change in neuropsych status, and complication. 29 consecutive subjects were identified and reviewed; 13 (44.8%) underwent temporal lobe only resections; extra-temporal resections included 6 (20.7%) frontal; 1 (3.4%) parietal, 9 (31%) multi-lobe. In subjects with available follow-up data, 13/25 (52%) were seizure free at 12-months and 9/20 (45%) were seizure free at 24-months. At 12-months, 7/11 (63%) patients with temporal lobectomy were seizure free compared with 6/14 (43%) with extra-temporal resections. Age of epilepsy onset, duration, and etiology did not vary between outcome groups of Engel class I or II vs Engel class III or IV. Subjects with [lt]2 diagnostic variables in conflict were significantly more likely to be in Engel I or II at 12- (p[lt]0.001) and 24-months (p[lt]0.001) by Fischer[rsquo]s Exact Test. 12/16 (75%) of subjects with [lt]2 conflicting variables were seizure free at 12- months. Supporting and neutral variables did not differ between the outcome groups. The majority of conflicting variables were noted through scalp EEG recording, however conflicting MRI and neuropsychological variables also contributed to poor outcome. Subjects with [lt]2 diagnostic abnormalities contralateral to the targeted epileptogenic zone achieved Engel class I or II surgical outcome in 93% and 87% of cases at 12- and 24- months respectively. None of the individuals with [lt]2 conflicting variables attained Engel I or II outcome at 24-months.