Abstracts

RATIONALE: Pathological findings in temporal neocortex have not been extensively investigated in comparison with those of medial structures of temporal lobe. The objective of this study was to investigate the clinical, imaging, electrophysiological, and pathological findings and to determine the surgical strategy in the patients who showed positive findings in the neocortex of temporal lobectomy specimen
METHODS: We selected 90 patients who showed [dsquote]epileptic pathology[dsquote] from a cohort of [gt] 250 cases of temporal lobectomy which were performed between 1992 and 2000. Patients with brain tumor and vascular lesions were excluded. All the patients underwent temporal lobectomy after thorough evaluation according to preoperative investigation protocol. All the patients were followed up more than 12 months. Seizure outcome was classified according to Engel[ssquote]s classification.
RESULTS: Pathological examination showed epileptic tumor in 6, Taylor type cortical dysplasia(CD) in 6, and occult CD in 78. However, hippocampal sclerosis(HS) was combined in 59 cases(66%). Past history revealed febrile convulsion in 21(20%). Aura was revealed in 36 (40%) and the most common form was psychic aura(20%). Sixty three patients (70%) showed the temporal lobe seizure patterns. Standard EEG showed unitemporal epileptiform disturbances in 41, bitemporal in 30 and multilobar abnormalities in 18. MRI findings showed negative in 8, unilateral hippocampal atrophy(HA)/sclerosis in 44, bilateral HA/HS in 12, CD in 7, tumors in 6, and others. Seizure outcome was graded as class 1 in 61(69%), class2 in 9(10 %), class 3 in 10 (11%), and Class 4 in 9(10%).
CONCLUSIONS: Cortical dysplasia was the most common findings in temporal neocortex in this study. HS was frequently associated with CD. These findings suggest that CD may contributes to the genesis and expression of temporal lobe epilepsy.
[Supported by: Honam Medical Center]